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Europhysics Conference on High-Energy Physics 2011

Europe/Paris
Dauphine (Alpes Congrès - Alpexpo)

Dauphine

Alpes Congrès - Alpexpo

    • 16:00 18:30
      Registration 2h 30m EVE (University Campus)

      EVE

      University Campus

    • 18:30 19:45
      Welcome reception - cheese & wine party 1h 15m EVE (University Campus)

      EVE

      University Campus

    • 19:45 22:30
      General public inauguration show 2h 45m EVE (University Campus)

      EVE

      University Campus

      More info:
      http://lpsc.in2p3.fr/grand-public/nuits-des-particules.html

    • 09:00 10:30
      Astroparticle Physics Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 09:00
        Neutrino Telescope Mini-review 30m
        Orateur: Alexander Kappes (Humboldt-University Berlin / DESY)
        Slides
      • 09:30
        Searches for point sources of high energy cosmic neutrino with the ANTARES telescope 15m
        The ANTARES observatory is currently the largest neutrino telescope in the Northern Hemisphere. It is well suited to detect high energy neutrinos produced in astrophysical sources as it can observe a full hemisphere of the sky at all the times with a duty cycle close to unity and an angular resolution about 0.3 degrees. Due to its location in the South of France, ANTARES is sensitive to up-going neutrinos from many potential galactic sources in the TeV to PeV energy regime. Results from a time-integrated unbinned method as well as the sensitivity of the detector using 2007-2008 data are presented. Moreover, using a time-dependant search for the transient sources, the background rejection and point-source sensitivity can be drastically improved by selecting a narrow time window around the assumed neutrino production period. The gamma-ray light curves of blazars measured by the LAT instrument on-board the Fermi satellite reveal important time variability information. A strong correlation between the gamma-ray and the neutrino fluxes is expected in a hadronic scenario. First results on the search for nine bright and variable Fermi sources are also presented.
        Orateur: damien dornic (IFIC)
        Slides
      • 09:45
        Towards the Very Large Volume Mediterranean Neutrino Telescope, KM3NeT 15m
        KM3NeT ($km^3$ Neutrino Telescope) will be one of the world’s largest particle detectors, built at the bottom of the Mediterranean Sea, providing a window for the observation of the Universe through high energy neutrinos. KM3NeT will complement the South Polar IceCube neutrino telescope in its field of view and significantly surpass it in sensitivity and discovery potential. The underwater KM3NeT facilities will also provide continuous connectivity for long-term deep-sea scientific measurements in the geo- and biological sciences. In this talk we describe the major technical aspects of the KM3NeT design and we report on results concerning the evaluation of the sensitivity of the neutrino telescope to detect high energy astrophysical neutrinos. In particular, we present results on the discovery potential of the telescope in detecting galactic (point-like and extended) and extragalactic, transient (Gamma Ray Bursts) high energy neutrino sources as well as measuring the ultra high energy, diffuse neutrino flux.
        Orateur: Dr Apostolos Tsirigotis (Physics Laboratory, School of Science and Technology, Hellenic Open University)
        Slides
      • 10:00
        Probing Flavor Transition Mechanisms of Astrophysical Neutrinos 15m
        The determination of neutrino flavor transition mechanism by neutrino telescopes is presented. We first propose a model-independent parameterization for flavor transitions (such as standard three-flavor oscillations, neutrino decays or others)of astrophysical neutrinos propagating from their sources to the Earth. We demonstrate how one can constrain parameters of the above parameterization by performing flavor identifications in neutrino telescopes. Given the anticipated flavor discrimination capability in IceCube, we work out the allowed regions for the flavor transition parameters. The possibility of distinguishing neutrino decay models from the standard neutrino oscillation by IceCube detector is discussed.
        Orateur: Prof. Guey-Lin Lin (Institute of Physics, National Chiao-Tung University)
        Slides
      • 10:15
        Non-minimal Kaluza-Klein dark matter 15m
        We discuss experimental signatures of non-minimal Kaluza-Klein dark matter. In the minimal Universal Extra Dimensions model, there is a unique possible dark matter candidate, the first Kaluza-Klein excitation of the U(1) gauge boson B. On the other hand, in non-minimal models, allowing for general boundary localized terms, the mass spectrum is different, and such models allow for other dark matter candidates. In this talk, we focus on the first Kaluza-Klein excitations of the Z boson and the neutral Higgs boson. These are the possible non-minimal WIMP type candidates that are not already ruled out by experiments. For these dark matter particles, the phenomenological predictions are changed from the minimal Kaluza-Klein dark matter scenario. We discuss recent results on the relic abundance, the indirect detection signatures from neutrinos and gamma rays, and the prospects of direct detection.
        Orateur: Henrik Melbéus (Royal Institute of Technology (KTH))
        Transparents
    • 09:00 10:30
      Flavour Physics and Fundamental Symmetries Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 09:00
        Neutron EDM in Four Generation Standard Model 15m
        New experiments under construction aim to push neutron electric dipole moment down by one to two orders of magnitude, to an eventual sensitivity of 10^{−28} e cm. The Standard Model would still be out of reach. However, there is renewed interest in the direct search for a possible fourth generation of quarks, which may carry sufficient CP violation for the baryon asymmetry of the Universe. We estimate the neutron EDM in the presence of a fourth generation, and find it would be dominated by the strange quark chromoelectric dipole moment, assuming it does not get wiped out by a Peccei-Quinn symmetry. The three electroweak loop contribution is comparable in strength to the two-loop electroweak/one-loop gluonic contribution. With m_{b′}, m_{t′} at 500 GeV or so, and with a Jarlskog CPV factor that is consistent with hints of New Physics in b → s transitions, the neutron EDM is still far below 10^{−28} e cm.
        Orateur: Dr Fanrong Xu (National Taiwan University)
        Slides
      • 09:15
        Particle Physics at the high-precision/low-energy frontier with Ultracold Neutrons at the Institut Laue-Langevin in Grenoble 15m
        Due to their outstanding property to be storable and hence observable for long periods of time (several hundreds of seconds) in suitable material or magnetic traps, ultra-cold neutrons (UCN) with energies around 100 neV are an unique tool to study fundamental properties of the free neutron, like its beta-decay lifetime, its electric dipole moment and its wave properties. The search for the electric dipole moment (EDM) of the neutron plays a prominent role in particle physics because of its direct bearing on CP and T violation: a non-zero value of the neutron EDM would be evidence of CP and T violation. Precision measurements of the neutron lifetime provide stringent tests of the standard electroweak model as well as crucial inputs for tests of Big-Bang nucleosynthesis. Neutron lifetime can be related to CKM Matrix unitarity. Neutron lifetime also dominates the uncertainty in theoretical calculation of primordial 4He. In this talk current ILL experiments linked to these fundamental questions are presented and a brief outlook is given.
        Orateur: Dr Peter Geltenbort (Institut Laue-Langevin)
        Slides
      • 09:30
        The neutron Electric Dipole Moment experiment (nEDM) - exploring the low-energy precision frontier 15m
        The search for a permanent neutron electric dipole moment with ultracold neutrons (UCN) is one of the prominent experiments to test CP-violation at the low-energy precision frontier. Extensions to the SM can provide enough CP violation to accommodate for the observed baryon asymmetry of the universe, while at the same time predicting nEDM values in the range of 10^-26 to 10^-28 ecm. This is just below the present upper bound of 2.9*10^-26 ecm [1] which was limited mostly by counting statistics. An improved nEDM measurement is very timely and complements direct searches for new physics at the Large Hadron Collider. The nEDM Collaboration of 15 European institutes [2] prepares its first data taking phase at the high intensity superthermal UCN source at PSI [3] aiming to improve the nEDM sensitivity by a factor five within two years. The final goal of the collaboration is a factor 50 improvement with a newly designed instrument. Our research and development efforts with the present and future nEDM apparatus and connected systematics will be presented. [1] C.A. Baker et al.,Phys. Rev. Lett 97 (2006) 131801 [2] http://nedm.web.psi.ch [3] http://ucn.web.psi.ch
        Orateur: Dr Geza Zsigmond
        Slides
      • 09:45
        A New Limit on Time-Reversal-Invariance Violation in Beta Decay: Results of the emiT-II Experiment 15m
        We have measured the D-coefficient in the triple correlation of the neutron spin with proton and electron momenta by observing coincidences in the decay of polarized neutrons. A non-zero value of D can arise due to parity-even-time-reversal-odd interactions that imply CP violation due to the CPT theorem. (Final-state effects also contribute to D at the level of 1e-5 and can be calculated with precision of 1% or better [1]. The D coefficient is uniquely sensitive to the phase, φAV, of the ratio of axial-vector (A) and vector (V) amplitudes: λ=gA/gV as well as to scalar and tensor interactions that could arise due to beyond-Standard-Model physics such as leptoquarks [2]. The experiment was performed with the NG-6 cold-neutron beam at the NIST Center for Neutron Research in Gaithersburg, Maryland. The neutron beam is polarized, passes through a spin flipper and is collimated into a spectrometer, which measures proton-electron coincidences in an octagonal detector array concentric with the neutron beam. The recoil protons were accelerated to ~28 keV and detected by surface barrier detectors. The electrons were detected in plastic scintillators. The detector is highly segmented, allowing the triple correlation to be isolated and separated from a variety of systematic effects due to the parity-odd-time-reversal even correlations [3]. A 14-month run in 2002-2003 produced a sample of over 300 million proton- electron coincidence events. A blind analysis and extensive study of all significant systematic effects has recently been completed with the result D = (-0.96±1.89 (stat)±1.01(sys))e-4. The corresponding upper limit on D is a factor of three improvement over the previous upper limit for neutron decay [4,5] and over the upper limit measured in 19Ne decay [6], and thus our result represents the most sensitive test of time- reversal invariance in beta decay. Assuming only vector and axial vector interactions in beta decay, the result can be interpreted as a measure of the phase φAV = (180.013±0.028)°. This result also improves constrains on certain non-VA interactions. 1. S. Ando et al. Phys. Lett. B 667, 109 (2009). 2. P. Herczeg, in Proc. of the 6th Int. PASCOS-98, (1998). 3. H.P. Mumm et al., Rev. Sci. Inst. 75, 5343 (2004). 4. L.J. Lising et al. Phys. Rev. C 62, 055501 (2000). 5. T. Soldner et al. Physics Letters B 581 49 (2004). 6. A.L. Hallin et al., Phys. Rev. Lett. 52, 1054 (1984).
        Orateur: Dr Hans Pieter Mumm (NIST)
        Slides
      • 10:00
        Recent BABAR Tau Physics Results 15m
        We report recent BABAR results in tau physics, including a search for CP violation in tau -> Ks0 pu nu, a search for second class currents in the process tau -> K/pi eta nu, and discuss recent results of exclusive branching fraction measurements related to V_us.
        Orateur: Mme Aleksandra Adametz
        Slides
      • 10:15
        Rare tau decays at Belle 15m
        We report results of a search for tau lepton decays strongly suppressed in the Standard Model based on the world-largest data sample accumulated with the Belle detector at the KEKB asymmetric-energy e+e- collider. The decays include: lepton flavor and lepton number violating tau decays into a lepton (e or mu) and two charged mesons (K or pi), lepton flavor violating decays into a lepton (e or mu) and a photon as well as lepton and baryon number violating tau decays into a Lambda and a charged meson (K or pi). The sensitivity to the branching fractions is significantly improved compared to our previous results and in some cases reaches O(10^{-8}).
        Orateur: Dr Kiyoshi Hayasaka (Nagoya University)
        Slides
    • 09:00 10:30
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 09:00
        Tevatron anomalies and LHC cross-checks 30m
        Tevatron anomalies and LHC cross-checks
        Orateur: German Rodrigo
        Slides
      • 09:30
        Update on W+2jets at CDF 15m
        We present an updated study of the invariant mass and other kinematic distributions of jet pairs produced in association with a $W$ boson using data collected with the CDF detector utilizing an integrated luminosity of $\sim$ 7~fb$^{-1}$. The distributions are compared in detail to the Standard Model predictions.
        Orateur: Dr VIVIANA cavaliere (CDF Collaboration, University of Illinois at Urbana Champaign)
        Slides
      • 09:45
        Study of the dijet invariant mass distribution in $\boldsymbol{W+2}$ jet candidate events in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV 15m
        We present a study of the dijet invariant mass spectrum in events with at least two jets produced in association with a $W$ boson, using data collected with the D0 detector which correspond to an integrated luminosity of 4.3 fb$^{-1}$. We perform a detailed comparison of the observed distribution with the background prediction, taking into account systematic uncertainties, to check the presence of an excess in the 120-160 GeV region recently claimed by the CDF Collaboration.
        Orateur: Dr Jadranka Sekaric (University of Kansas)
        Transparents
      • 10:00
        New physics in the third generation quark sector: LHC predictions from LEP and Tevatron anomalies 15m
        The last decade of particle physics beyond the Standard Model has seen extensive developments on an alternative to supersymmetry: the scenarios with warped extra dimensions. Those constitute a new paradigm in the sense that they are dual, through the AdS/CFT correspondence, to composite Higgs models. These scenarios predict strong deviations from the Standard Model mainly in the bottom and top quark sector. In that sense, the LEP anomaly on forward-backward bottom asymmetry (A^b_FB) and the recent Tevatron anomalies on the top asymmetry (A^t_FB) could be interpreted as early signatures of such warped models. We will discuss warped model realizations allowing to address both A^b_FB and A^t_FB, taking also into account the new constraints issued from top pair and dijet production rates at the LHC. Then, I will describe what are the predictions of these warped models at LHC, pointing out the complementarity between Tevatron and LHC on top physics. There are typically two types of predicted signatures at LHC: a resonance peak in the top pair invariant mass distribution (due to the exchange of a Kaluza-Klein excitation of the gluon) or the production of exotic colored fermions (custodians) around a few hundred's of GeV.
        Orateur: Dr Grégory MOREAU (LPT/Orsay)
        Papier
        Transparents
      • 10:15
        Exotics Searches in Top, Top-like and Diboson Final States with the ATLAS Detector 15m
        We summarize the analysis of events with top, top-like and diboson final states in pp collision data recorded with the ATLAS detector. The data are compared to the Standard Model predictions with the goal of searching for new phenomena, e.g. searches for anomalous top-quark production and decay in several channels, including a search for top-quark pair production with anomalous missing transverse energy, top-quark pair resonances, fourth generation quarks decaying to top quarks, gravitons and heavy gauge bosons decaying into dibosons.
        Orateur: Thorsten Kuhl
        Slides
    • 09:00 10:30
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 09:00
        Jet Production at HERA with ZEUS 15m
        Differential inclusive-jet cross sections have been measured in photoproduction for boson virtualities Q2 < 1 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb-1. These cross sections have the potential to constrain the gluon density in the proton and the photon when included as input to fits to extract the proton parton distribution functions. A value of alphas(Mz) has been extracted from the measurements. For the first time, differential inclusive-jet cross sections have been measured in neutral current deep inelastic ep scattering using the anti-kt and SIScone algorithms, as well as the nominal kt cluster algorithm. The measurements were made for boson virtualities Q2 > 125 GeV2 and the jets were identified in the Breit frame. Measurements of the ratios of cross sections using different jet algorithms are also presented and values of alphas(Mz) are extracted from the data. Single- and double-differential inclusive dijet cross sections in neutral current deep inelastic ep scattering have been measured using an integrated luminosity of 374 pb-1. The measurement was performed at large values of the photon virtuality, Q2, between 125 and 20000 GeV2. Single- and double-differential dijet cross sections have also been measured in photoproduction for boson virtualities Q2 < 1 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb-1. These cross sections have the potential to constrain the gluon density in the proton and the photon when included as input to fits to extract the proton parton distribution functions. Next-to-leading-order QCD calculations give a good description of the measurements.
        Orateur: Joerg Behr
        Slides
      • 09:15
        Jet Production at HERA and determination of alpha_s with H1 15m
        Inclusive-jet, dijet and trijet differential cross sections have been measured in neutral current deep-inelastic ep scattering for exchanged boson virtualities 150 < Q2 < 15000 GeV2 with the H1 detector at HERA. The measurements are used to determine value of the strong coupling alpha_s(M_Z). Additionally, the production of jets is studied at low four momentum transfer squared $5 < Q2 < 100 GeV2$ using integrated luminosity of 300 $pb^{-1}$. Cross sections are measured as a function of Q2 and jet transverse momentum and compared to the perturbative next-to-leading order QCD calculations corrected for hadronisation effects. Finally, the production of jets is studied in deep-inelastic e+p scattering at low negative four momentum transfer squared 5 < Q2 < 100 GeV2 and at inelasticity 0.2 < y < 0.7 using data recorded by the H1 detector at HERA in the years 1999 and 2000, corresponding to an integrated luminosity of 43.5 pb-1. Inclusive jet, 2-jet and 3-jet cross sections as well as the ratio of 3-jet to 2-jet cross sections are measured as a function of Q2 and jet transverse momentum. The 2-jet cross section is also measured as a function of the proton momentum fraction xi. The measurements are well described by perturbative quantum chromodynamics at next-to-leading order corrected for hadronisation effects and are subsequently used to extract the strong coupling alpha_s.
        Orateur: Artem Baghdasaryan
        Slides
      • 09:30
        Meaningful characterisation of perturbative theoretical uncertainties 15m
        We consider the problem of assigning a meaningful confidence to uncertainty estimates of perturbative series. We analyse the assumptions which are implicit in the conventional estimates made using renormalisation scale variations. We then formulate a Bayesian model that, given equivalent initial hypotheses, allows one to characterise a perturbative theoretical uncertainty in a rigorous way in terms of the confidence of an interval for the remainder of the series. We compare its outcome to the conventional uncertainty estimates in the simple case of the calculation of QCD corrections to the e+e- -> hadrons process. We find comparable results, but with important conceptual differences. This work represents a first step in the direction of a more comprehensive and rigorous handling of theoretical uncertainties in perturbative calculations used in high energy phenomenology.
        Orateur: Nicolas Houdeau (LPTHE (CNRS - UPMC))
        Transparents
      • 09:45
        Inclusive jet and dijet cross-section measurements in CMS 15m
        We present inclusive jet and dijet cross-section measurements in proton-proton collisions at a center-of-mass energy of 7 TeV at the CERN LHC, using the 2010 data collected by the CMS experiment. The data are compared to NLO pQCD predictions and are found to be in good agreement.
        Orateur: Keith Jarid Rose
        Slides
      • 10:00
        Multijet measurements with the CMS detector at 7TeV 15m
        We present measurements sensitive to QCD multijet production using data from proton-proton collisions at sqrt(s) = 7 TeV collected with the CMS detector at the CERN LHC. The hadronic event shapes, the dijet azimuthal decorrelation and the ratio of the 3 jet to 2 jet production cross-sections confront the QCD multijet dynamics at a previously unexplored kinematic regime. The data are compared to various QCD Monte Carlo models.
        Orateur: Prof. Panagiotis Kokkas (University of Ioannina - Greece)
        Slides
      • 10:15
        Measurement of single and multi-jet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with ATLAS 15m
        Single and multiple et cross sections have been measured in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The anti-kt algorithm is used to identify jets. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and angle. The measurements extend the previously measured kinematic region to higher rapidities, and to both higher and lower values of transverse momentum. The results are compared to next-to-leading-order QCD calculations matched to leading-logarithmic parton showers. Additionally, measurements are presented of multijet cross sections, and of the azimuthal correlation between dijets, which are sensivitive to higher or QCD effects. Measurements of dijets separated by large intervals of rapidity are also presented, where a veto is applied based on the presence of further jets with the rapdity interval. The measurements are compared to NLO QCD and higher multiplictity LO QCD calculations matched to parton showers using leading-logarithmic approximations in the scale, Q2. The large rapdity-interval distribitions are also compared to calcultations using approximations based on resumming the leading-logarthmic terms in rapidity.
        Orateur: M. Paolo Francavilla (Universita' di Pisa)
        Transparents
    • 09:00 10:30
      Top and Electroweak Physics Stendhal

      Stendhal

      Alpes Congrès - Alpexpo

      Président de session: Dr Jan Stark (Stark)
      • 09:00
        Top-quark production at hadron colliders 30m
        Mini-review.
        Orateur: Dr Roberto Bonciani (LPSC)
        Slides
      • 09:30
        Measurements of single top production in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV utilizing data collected with the D0 detector at the Fermilab Tevatron Collider 20m
        We present studies of single top production using the D0 experiment. Single top events are selected with an isolated electron or muon missing transverse energy, two, three or four jets, with one or of them identified as originating from the fragmentation of $b$ quarks. From the cross section measurement we obtain new bounds on the Kobayashi-Maskawa $|V_{tb}|$ matrix element. A model-independent measurement of $t$-channel electroweak production of single top gives a cross section $\sigma(p\bar{p}\to tbq+X)=2.90\pm0.59{\text(stat+syst)}$ pb for a top quark mass of 172.5 GeV. We estimate the probability of the background to fluctuate and produce a signal as large as the one observed to be $1.6\times10^{-8}$, corresponding to a significance of 5.5 standard deviations. We also present search for anomalous top quark production and for CP violation in single top production. The total width of the top quark, $\Gamma_t$, is measured from the partial decay width $\Gamma(t\to Wb)$ measured using the $t$-channel cross section for single top quark production and from the branching fraction $\mathcal{B}(t\to Wb)$ measured in $t\bar{t}$ events
        Orateur: Shabnam Jabeen (Brown University)
        Slides
      • 09:50
        Single-top quark studies in ATLAS 20m
        We present the result of searches for single top-quark production in the t- and Wt-channels in 7 TeV proton-proton collisions with the ATLAS detector. The t-channel search is based on the selection of events with a single lepton (muon or electron), jets and missing transverse energy. The Wt-channel analysis is based on the selection of events with one or two leptons, jets and missing transverse energy.
        Orateur: Dominic Hirschbuehl
        Slides
      • 10:10
        Measurement of single top production in pp collisions at 7 TeV with the CMS detector 20m
        We present a measurement of the inclusive single top production cross section in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV, using data collected with the CMS experiment during the year 2011. The analysis considers decay channels where the W from the top decays into electron-neutrino or muon-neutrino, and makes use of kinematic characteristics of electroweak single top production for the separation of signal from backgrounds using multivariate methods. The result, which supersedes an earlier measurement based on 2010 data, is compared with the most precise standard model theory predictions. We also present measurements of various differential single top quark production cross sections. In addition, we present the first measurement of single top quark production in the tW-channel in pp collisions, in which a top quark is produced in association with a W boson. The experimental signature is similar to top pair production, and there is interference at higher orders between the two processes. The measurement is performed using final states in which the associated W boson as well as the one originating from the top quark decay leptonically. Multivariate methods are used to extract the cross section. The result is compared with current standard model theory predictions.
        Orateur: Alberto Orso Maria Iorio (stituto Nazionale di Fisica Nucleare (INFN))
        Transparents
    • 09:00 10:30
      Ultrarelativistic Heavy Ions Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      Président de session: Jose Guilherme Milhano
      • 09:00
        ATLAS Results on Pb+Pb Collisions 30m
        A wide research program provided by heavy ion collisions is ongoing at the Large Hadron Collider with the aim of studying the properties of QCD matter at extreme temperatures and densities. The large acceptance, high granularity and broad pseudorapidity coverage of the ATLAS Detector is well suited to perform detailed analyses on bulk phenomena, jets and leptonic probes. Measurements of these observables provided by the 9 \mub-1 of Pb+Pb collision data collected during the Fall 2010 Pb+Pb run at the nucleon-nucleon center of mass energy of 2.76 GeV are presented.
        Orateur: Dr Helena Santos (LIP)
        Transparents
      • 09:30
        Overview of CMS results from heavy-ion collisions 30m
        We will present results of the CMS experiment from PbPb collisions at $srqrt{s_{NN}}$ = 2.76 TeV, probing quark and gluon matter at unprecedented values of energy density. The CMS apparatus provides calorimetry, muon and tracking systems covering a large range in pseudorapidity, complemented by a flexible two-level trigger system. This allows us to study the production of jets, photons, charged hadrons, quarkonia and vector bosons at large transverse momenta as a function of collision centrality. In addition, the large acceptance enables detailed studies of particle correlations in heavy ion collisions.
        Orateur: Yen-Jie Lee (Massachusetts Institute of Technology)
        Slides
      • 10:00
        ALICE results for Pb-Pb collisions 30m
        ALICE (A Large Ion Collider Experiment) is the LHC experiment specifically designed to study QCD matter under extreme conditions of temperature and pressure. The aim is to study the Quark-Gluon Plasma obtained with high energy nucleus-nucleus collisions and to characterize its properties. Results from the ALICE experiment for sqrt(s_NN)=2.76 TeV Pb-Pb collisions will be presented and compared with predictions and lower energy heavy-ion collisions.
        Orateur: Dr Boris Hippolyte (IPHC Strasburg)
        Transparents
    • 10:30 11:00
      Coffee 30m Lobby

      Lobby

      Alpes Congrès - Alpexpo

    • 11:00 13:00
      Astroparticle Physics Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 11:00
        Gamma&Cosmic Rays Mini-review 30m
        Orateur: Javier Rico
        Slides
      • 11:30
        Measurement of the cosmic ray energy spectrum above 1 EeV at the Pierre Auger Observatory 15m
        Authorship: The Pierre Auger Collaboration The Pierre Auger Observatory is measuring the ultra-high energy cosmic ray extended air showers from simultaneous observation of fluorescence and surface detectors with unprecedented precision. The high statistics of the surface detector allows a good determination of the cosmic ray flux above an energy of 3 EeV. This bound is extended down to 1 EeV using a unique technique that exploits the hybrid detection power. The spectrum is presented displaying two clear features in the energy range between 1 and 100 EeV.
        Orateur: Dr Corinne Berat (LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble)
        Transparents
      • 11:45
        Searches for anisotropies of cosmic rays at the Pierre Auger Observatory 15m
        We report on the analysis of the distribution of the arrival directions of ultra high energy cosmic rays detected at the Pierre Auger Observatory. From $2.10^{17}~$eV to $3.10^{19}~$eV, we present the results of searches for first harmonic modulations in the right-ascension distribution of cosmic rays and discuss the obtained upper limits which constitute the most stringent bounds at present above $2.10^{17}~$eV. At the highest energies, the observation of the flux steepening is consistent with the shortening of the horizon of ultra high energy cosmic rays and leads to the possibility of "cosmic ray astronomy". Thus, we present the analyses searching for correlation of cosmic rays with nearby extragalactic astrophysical objects.
        Orateur: Haris, for the Pierre Auger Collaboration Lyberis (Institut de Physique Nucléaire d'Orsay, Università degli Studi di Torino, Université Paris VII Denis Diderot)
        Slides
      • 12:00
        Mass composition of Ultra High Energy Cosmic Rays at the Pierre Auger Observatory 15m
        Authorship: The Pierre Auger Collaboration The mass composition of ultra-high energy cosmic rays is a critical issue to understand their origin and nature. The Pierre Auger Observatory is a hybrid instrument which provides a powerful environment for the determination of the primary mass, being able to discriminate between photons, neutrinos and hadrons. Results on limits of photon and neutrino fluxes together with hadronic identification are presented. The dependence of average primary mass with energy by comparison with current predictions from models is finally discussed.
        Orateur: Dr Hernan Wahlberg (IFLP - Universidad Nacional de La Plata)
        Transparents
      • 12:15
        Gamma-ray astronomy and cosmic-ray physics with ARGO-YBJ 15m
        The ARGO-YBJ detector, located 4300 m a.s.l. on the Tibet plateau, is a ground-based, full-coverage array of Resistive Plate Chambers (RPCs) covering a surface of 78 x 74 m^2, surrounded by a guard ring of RPCs enclosing a total surface of about 11000 m^2. ARGOYBJ was designed to detect extensive air showers generated by cosmic rays and gamma rays with primary energy greater than few hundred GeV, in order to study the region of the cosmic-ray spectrum out of the reach of both satellite-based experiments and traditional ground-based arrays. The experiment has been running with its complete layout since November 2007, collecting over 2.5 x 10^11 events. The main results obtained by ARGO-YBJ will be presented here, and specifically: - the monitoring of astronomical gamma-ray sources, such as the Crab nebula and the MRK 421 AGN; - the moon shadow; - the intermediate-scale and large-scale anisotropy map; - the proton-proton inelastic cross section at center-of-mass energy between 70 and 500 GeV where no accelerator data are available.
        Orateur: Dr Paolo Camarri (University of Roma "Tor Vergata" and INFN Roma Tor Vergata)
        Slides
      • 12:30
        LHCf physics results and future perspectives 15m
        The LHCf experiment is a double arm sampling calorimeter, installed +/-140 m away from the Atlas LHC interaction point. The detectors allow precise measurement of energy and impact point of the neutral particles (mainly photons and neutrons) produced very forward in the LHC proton-proton interactions, in the pseudorapidity region greater than 8; this measurement is crucial for the calibration of the hadronic interaction models widely used in the High Energy Cosmic Ray field. The experiment has successfully taken data in 2010, at 7 TeV center of mass energy, and it was later on removed to avoid radiation damage once the LHC luminosity was increased. In this talk the main LHCf physics results will be reported, focusing in particular in the single photon energy spectra comparison between experimental data and the expectations of the various models. The upgrade phase, foreseen to reduce the radiation damage effects in the next 14 TeV 2014 center of mass energy run, will also be presented.
        Orateur: Prof. Alessia Tricomi (University and INFN Catania)
        Slides
      • 12:45
        Density Imaging of Volcanoes With Atmospheric Muons using GRPCs 15m
        Their capability to penetrate through large depths of material renders high-energy atmospheric muons a unique probe for geophysical studies. Provided the topography is known, the measurement of the attenuation of the muon flux permits a cartography of density distributions revealing spatial and possibly also temporal variations. A Collaboration between volcanologists, astroparticle- and particle physicists, TOMUVOL, has been formed in 2009 to study tomographic muon imaging of volcanoes with high-resolution, large-scale tracking detectors. By exploiting Glass Resistive Plate Chambers (GRPCs) with a semidigital readout developped for ILC hadronic calorimetry within the CALICE collaboration, TOMUVOL aims to improve the understanding of volcanic processes and may finally contribute to reducing volcanic hazards. Presently TOMUVOL is operating a muon telescope at the flank of the Puy de Dôme, an inactive volcanic dome situated in the Massif Central (south-central France). Three GPRC planes are in continuous operation, controlled remotely through a long-range Wifi link. This contribution presents the geophysical motivation for muon imaging as well as the results after several months of data taking at the Puy de Dôme including measurements of the horizontal muon flux and first radiographic images.
        Orateur: Dr Cristina Carloganu (LPC Clermont Ferrand)
        Slides
    • 11:00 13:00
      Flavour Physics and Fundamental Symmetries Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 11:00
        Charmless Hadronic B Decays with BABAR 15m
        We present recent BABAR results on charmless hadronic B decays. In particular, we measure the branching fractions, longitudinal polarization fraction f_L and charge asymmetry in B -> rho(f_0) K* events, and report results of studies of B -> phi phi K and B0->K+pi-pi0. We also present the results of a recent study of the inclusive branching fractions of B-meson decays to charmless final states containing a charged or neutral kaon.
        Orateur: Eugenia Puccio
        Slides
      • 11:15
        Recent BABAR results on CP violation in B decays 15m
        We report on the study of the decay B+ ->D0(D0bar) K+ where the D0 or D0bar decaying to Kpipi0, with the Atwood Dunietz and Soni (ADS) method. We measure the ratios Rads, R+, and R- that, since the processes B+ -> D0barK+ and B+ -> D0K+ are proportional to Vcb and Vub, respectively, are sensitive to rB and to the weak phase gamma. We also report the results of CP violation studies of B->Dcp pi+pi- and B0->D*D*.
        Orateur: M. Denis Derkach
        Transparents
      • 11:30
        phi2 and phi3 measurements at Belle 15m
        We present a time-dependent measurement of CP violation parameters in $B^0 \to \pi^+\pi^-$ decays. We present also a measurement of the branching fraction of $B^0 \to \rho^0 \rho^0$ decays, which could provide a tighter constraint of the CKM angle $\phi_2$. In addition we present measurements of branching ratios of other charmless $B$ decays into 4 charged pions. We present a measurement of the branching fraction and time-dependent CP violation parameters of $B^0 \to a_1^{\pm}\pi^{\mp}$ decays. The measurement of $B\to\pi^0\pi^0$ is vital in the extraction of the UT angle $\phi_2$, from an isospin analysis of the $B\to\pi\pi$ system. In addition, this process is expected to exhibit direct CP violation, a measurement of which would place additional constraints on $\phi_{2}$, and a new measurement of $B\rightarrow\pi^0\pi^0$ would help resolve the significant disagreement in the Belle and BaBar measurements of this mode. The decay $B^- \to D^{(*)} K^-$ ($D = D^0$ or $\bar{D}^0$) includes the $b \to u$ transition and plays a crucial role in the measurement of the CP-violating angle $\phi_3$. We present the results of a study of the decay $B \to D^{(*)} K^-$ where the $D$ meson is reconstructed from $K^+ \pi^-$ and from $CP$ modes. We report the first measurement of the angle $\phi_{3}$ of the unitarity triangle using a binned model-independent Dalitz plot analysis technique of $B^{\pm} \rightarrow DK^{\pm}$, $D \rightarrow K^{0}_{S}\pi^{+}\pi^{║щ}$ decay chain. These results are obtained from the final data sample that contains 772 million $B\overline{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.
        Orateur: Dr Jeremy Dalseno (MPI, Munich)
        Slides
      • 11:45
        Direct CPV and charmless B decays at Belle 15m
        We report the measurements of branching fractions and direct $CP$ asymmetries for neutral $B$ meson decays to the $hh$ final states, where $h$ stands for a pion or a kaon. We also study the charged $B$ meson decays into one charged and one neutral kaon or pion. We present improved measurements of the branching fraction and the $CP$ asymmetry of $B\to\eta h$. Here $h$ denotes $\pi^{\pm}$, $K^{\pm}$ or $K^0_S$, and the $\eta$ is reconstructed through the decay channels $\eta\to\gamma\gamma$ and $\eta\to\pi^+\pi^-\pi^0$. We report the results of a search for the charmless hadronic decay $B^+ \to \omega\rho^+$. These analyses are performed using the large data sample collected with the Belle detector near the $\Upsilon(4S)$ resonance at the KEKB asymmetric $e^+e^-$ collider.
        Orateur: Dr Paoti Chang (NTU, Taipei)
        Transparents
      • 12:00
        Updated measurements of hadronic B decays at CDF 15m
        We present the updated analysis of Bd, Bs , and Lambda_b decays into charmless two-body final states using 6/fb of data collected by the CDF experiment. We report the first evidence for the pure-annihilation decay Bs->pi^+pi^- and improved limits on the Bd->K+K- branching ratio. We also report the first measurement of branching fractions and CP-violating asymmetries of doubly-Cabibbo suppressed B+ --> D0 K decays in hadron collisions, using the approach proposed by Atwood, Dunietz, and Soni (ADS) to infer information on the CKM angle gamma in 7.0 fb-1 of data. The relevant parameters are determined with accuracy competitive with best B factory measurements.
        Orateur: Dr Michael Joseph Morello (INFN and University of Pisa)
        Slides
      • 12:15
        CPV and CPT in B decays at Belle 15m
        Using the large data sample collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we present an improved measurement of time-dependent CP violation in the neutral $B$ decays into charmonium and $K^0$. CPT is expected to be a fundamental symmetry with no significant deviations. Nonetheless we can introduce an artificial perturbation parameter to the $B^0-\bar{B}^0$ mixing system that violates CPT symmetry. The CPT violating parameter, which is a complex number but expected to be zero, can be probed through proper time difference distributions in correlated B meson pair decays. We present a measurement of the CPT violating parameter. We report measurements of branching fractions and CP violation parameters in the neutral B meson decays into $D^+D^-$ and $D^{*+}D^{*-}$. We report the first observation of the radiative decay $B^0 \to \phi K^0 \gamma$ and measurements of time-dependent $CP$-violation. These measurements are sensitive to new physics from right-handed currents. We also report an updated measurement of the branching fraction in $B^+ \to \phi K^+ \gamma$ as well as measurements of a new radiative penguin decay $B \to \omega K^{+}(K^0) \gamma$.
        Orateur: Dr takeo Higuchi (KEK, Tsukuba)
        Slides
      • 12:30
        The study of gamma/phi_3-sensitive hadronic decays at LHCb 15m
        Temporary : merging of (abstracts 380,386,396) The relative abundances of the three decay modes B0 -> DK, B0 -> Dπ and Bs ->Dsπ produced in 7 TeV pp collisions at the LHC are determined from data corresponding to an integrated luminosity of ∼35 pb−1. The relative branching ratio of B0 -> DK with respect to B0 -> Dπ is found to be B(B0 ->DK) = (2.01 \pm 0.18 stat \pm 0.12 syst ) x 10−4 . The ratio of fragmentation fractions fs /fd is determined through the relative abundances of B0 -> DK and B0 -> Dπ with respect to Bs -> Dsπ, leading to fs /fd = 0.253 \pm 0.017 \pm 0.018 \pm 0.020, where the uncertainties are respectively statistical, systematic, and theoretical. Using a large data sample accumulated at a centre-of-mass energy √s = 7 TeV with the CERN LHCb experiment, we study the decays B± -> DK± where the neutral D meson decays into two track final states. These measurements are sensitive to the value of the CKM Unitarity Triangle angle gamma. Using data collected by the LHCb detector we reconstruct a sample of the main charmless charged two-body $B$ hadron decay modes, namely $B^0 \rightarrow \pi^+\pi^-$, $B^0 \rightarrow K^+\pi^-$, $B^0_s \rightarrow K^+K^-$, $B^0_s \rightarrow \pi^+K^-$, $\Lambda_b \rightarrow p K^-$ and $\Lambda_b \rightarrow p \pi^-$. We provide preliminary values of the direct $\mathcal{CP}$ asymmetries in the $B^0 \rightarrow K^+\pi^-$ and $B^0_s \rightarrow \pi^+K^-$ decays, of the relative branching fractions and of the $B^0_s \rightarrow K^+K^-$ lifetime. We also discuss the prospects for the measurement of time-dependent CP violation in the $B^0 \rightarrow \pi^+\pi^-$ and $B^0_s \rightarrow K^+K^-$ decays.
        Orateur: M. Angelo Carbone
        Slides
      • 12:45
        The SuperB physics programme 15m
        The study of B_{u,d,s} and D decays at SuperB can provide both stringent constraints on new physics scenarios, and over constraints on the CKM description of quark mixing and CP violation in the Standard Model. The rich landscape of new physics sensitive observables in both tree dominated and loop or flavor changing neutral current rare decays complements measurements possible at existing facilities. We discuss the physics potential of what can be learned from B and D decays at SuperB. One of the unique features of SuperB is a polarized electron beam. This opens the way for SuperB to be a Super tau factory, capable of performing precision tau measurements and searches for CP violation and charged Lepton Flavor Violation, as well as performing precision electroweak physics, including the measurement of sin^2theta_W at energies corresponding to the Y(4S) and psi(3770).
        Orateur: M. Alberto Lusiani
        Transparents
    • 11:00 13:00
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 11:00
        Search for New Physics in the All-Hadronic Final States at CMS 20m
        We present results of a number of searches for new physics in all-hadronic final state using pp data at the center-of-mass energy of 7 TeV collected with the CMS detector at the LHC in 2010 and 2011. The sought signals include monojet production in models with large extra dimensions, high-mass resonances decaying in ttbar pairs in all-hadronic decay channel, microscopic black holes, quark compositeness, and resonances decaying into multijet final states.
        Orateur: Kai Yi
        Transparents
      • 11:20
        Exotics Searches in Jet Final States with the ATLAS detector 20m
        We summarize the analysis of events with jets in the final state in pp collision data recorded with the ATLAS detector. The data are compared to Standard Model predictions with the goal of searching for new phenomena: heavy resonances, contact interactions and gravitationally-mediated effects in large extra dimensions, including gravitational scattering and quantum micro-black holes.
        Orateur: Adam Gibson
        Slides
      • 11:40
        Search for Non-Resonant New Phenomena in the Lepton and Photon Final States 20m
        We present the results of a search for non-resonant signal for new physics in leptonic and photonic final states in pp collisions at 7 TeV collected with CMS in 2010 and 2011. These include searches for W'(lv), first and second generation leptoquarks, large extra dimensions in dilepton and diphoton channel, quark-lepton compositeness, anomalies in the transverse momentum of the leptonically decaying Z-bosons, and RPV SUSY in multilepton final states.
        Orateur: Christos Leonidopoulos (FNAL)
        Slides
      • 12:00
        Exotics Searches in Photon and Lepton Final States with the ATLAS Detector 20m
        Studies of leptons and photons at the Large Hadron Collider are some of the most direct and sensitive ways to search for new phenomena. We present the results based on data collected with the ATLAS detector at the LHC and discuss current sensitivities and future discovery prospects.
        Orateur: Tetiana Hryn'ova (LAPP)
        Slides
      • 12:20
        Search for narrow resonances in the lepton, photon, and jet final states at CMS 15m
        We discuss the results of searches for narrow resonances decaying into pairs of leptons, photons, or jets, using pp collisions at 7 TeV delivered by LHC and collected with the CMS detector in 2010 and 2011. These include searches for Z' bosons, RS gravitons, dijet resonances, and excited leptons.
        Orateur: Jordan Tucker
        Slides
      • 12:35
        Search for long-lived massive particles at CMS 15m
        Several models of new physics, including split supersymmetry, predict the existence of a heavy particle, which is long-lived on timescales of the bunch spacing of the LHC. We present the results of several searches for these particles, using various experimental techniques, from out-of-time decays in the CMS calorimeter to use of highly displaced vertices, timing, and dE/dx techniques. We present results of these searches based on data recorded with CMS in 2010 and 2011.
        Orateur: Jie Chen
        Slides
      • 12:50
        Search for heavy resonances decaying into ZZ at CDF 10m
        We report on a search for heavy resonances decaying into pairs of Z bosons using 6fb^-1 of ppbar collisions at sqrt(s)=2TeV collected by CDF. The analysis explores three final states corresponding to decays of Z pairs into four charged leptons, two charged leptons plus neutrinos, and two charged leptons plus jets. The results of the search are interpreted in the framework of theoretical models that predict heavy resonances decaying into ZZ, and for heavy resonance masses above 300GeV/c^2 we are sensitive to production cross-sections times branching ratio to ZZ below 0.2pb.
        Orateur: Dr Aidan Robson (Glasgow University)
        Transparents
    • 11:00 13:00
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 11:00
        Measurement of three-jet differential cross sections $\boldsymbol{d\sigma_{\text{3jet}} / dM_{\text{3jet}}}$ in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV 15m
        We present the first measurement of the inclusive three-jet differential cross section as a function of the invariant mass of the three jets with the largest transverse momenta in an event in $p\bar{p}$ collisions at $\sqrt{s}=1.96\, \mathrm{TeV}$. The measurement is made in different rapidity regions and for different jet transverse momentum requirements and is based on a data set corresponding to an integrated luminosity of $0.7\, \mathrm{fb}^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider. The results are used to test the three-jet matrix elements in perturbative QCD calculations at next-to-leading order in the strong coupling constant. The data allow discrimination between parametrizations of the parton distribution functions of the proton.
        Orateur: Dr Peter Svoisky (University of Oklahoma)
        Transparents
      • 11:15
        POWHEG: status and perspectives 15m
        I will review recent developments and applications of the POWHEG method, to merge NLO calculations with Shower Monte Carlo programs, in the POWHEG-BOX framework. Particular emphasis will be given to comparisons with LHC data and on the implementation of new processes.
        Orateur: Dr Simone Alioli (DESY)
        Transparents
      • 11:30
        Study of Substructure of High Transverse Momentum Jets Produced in Proton-Antiproton Collisions at \sqrt{s} = 1.96 TeV 15m
        We present a study of the substructure of jets with transverse momentum greater than 400 GeV/c produced in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider and recorded by the CDF II detector. We measure for the first time the distributions of the jet mass, angularity and planar flow in a 5.95/fb data sample. The observed substructure for high mass jets are found to be consistent with predictions from perturbative quantum chromodynamics.
        Orateur: M. Raz Alon (Weizmann Institute of Science)
        Slides
      • 11:45
        NLO event samples for the LHC 15m
        We introduce a twiki page with collections of generated event samples at LHC energies including a heavy quark-antiquark pair. These samples are generated with the POWHEG method and can be used to preparedistributions at the NLO accuracy with first radiation treated according to the parton shower approach. The event files are stored according to the Les Houches accord and standard parton shower Monte Carlo programs can be used to shower these events further and simulate events at the hadron level, ready for almost arbitrary experimental analysis. Currently the available final states are the following: (i) t + T, (ii) t + T + H, (iii) t + T + b + B, (iv) t + T + jet, while the generation of four other final states are in progress.
        Orateur: Prof. Zoltan Trocsanyi (University of Debrecen)
        Slides
      • 12:00
        Studies of the internal properies of jets with the ATLAS detector 15m
        The internal properties of jets are sensitive to fragmentation and QCD radition. Jet substricture may be used to indentify the decays of boosted hadronically decaying particles. Measurements of jets shapes, of single-jet mass, of charged particle multiplcitites, and of some key substructure variables are presented and compared to QCD calculations.
        Orateur: David Miller
        Slides
      • 12:15
        Analysis of the anomalous-dimension matrix of n-jet operators in SCET to 4 loops 15m
        Extending previous results obtained in arXiv:0903.1126, we perform a diagrammatic analysis of the anomalous-dimension matrix of n-jet operators in SCET, investigating for possible new structures arising at 4 loop.
        Orateur: Dr Leonardo Vernazza (Johannes-Gutenberg-Universität)
        Transparents
      • 12:45
        Jet resolution and energy scale uncertainty in ATLAS 15m
        About one year after the first proton proton collisions at a centre of mass energy of sqrt(s)= 7 TeV the ATLAS experiment has achieved an accuracy of the jet energy measurement between 2-4% for jet transverse momenta from 20 GeV to 2 TeV in the pseudo-rapidity region up to eta=4.5. The jet energy scale uncertainty is derived from in-situ single hadron response measurement a long with systematic variations in the Monte Carlo simulation. In addition, the transverse momentum balance between a central and a forward jet in events with only two jets at high transverse momentum is exploited. The obtained uncertainty is confirmed by direct in-situ measurements exploiting the transverse momentum balance between a jet and a well measured reference like the photon transverse in photon-jet events or the total transverse track momentum. Jets in the TeV-energy regime can be also tested using a system of well calibrated jets at low transverse momenta against a high-pt jet. The jet energy resolution can be determined in in-situ from the measurement of the transverse momentum balance of a system of two jets (transverse momentum asymmetry). The measurement is based on the direct transverse momentum balance and a decomposition of the transverse jet momentum along the bi-sector of the two jets. Good agreement between data and Monte Carlo simulations is found. Sophisticated jet calibration schemes based on cell energy weighting or exploiting the internal jet structure are also presented. Such calibration schemes improve the jet resolution by 20-30% and in addition reduce the flavour dependence of the jet response.
        Orateur: Caterina Doglioni
        Transparents
    • 11:00 13:00
      Top and Electroweak Physics Stendhal

      Stendhal

      Alpes Congrès - Alpexpo

      Président de session: Prof. Stefan Dittmaier Dittmaier (University of Freiburg)
      • 11:00
        Measurement of the top pair production cross section and properties of top quark production and decay in proton-antiproton collisions at $\boldsymbol{\sqrt{s}}$=1.96 TeV using the D0 Detector 30m
        We present measurements of the inclusive top quark pair production cross section in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV utilizing data collected with the D0 detector at the Fermilab Tevatron Collider. Results for the lepton (e or mu)+jet, dilepton, tau+jet and fully hadronic decay modes are provided. We also present a measurement of the forward-backward charge asymmetry in top quark production and use the cross section measurements to extract the branching ratio $\boldsymbol{B(t\to Wb)/B(t\to Wq)}$
        Orateur: Dr Christian Schwanenberger (University of Manchester)
        Transparents
      • 11:30
        Measurements of the top quark pair production cross section in pp collisions at 7 TeV using the CMS detector 30m
        We present several measurements of the top-pair production cross section in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. We use data collected with the CMS experiment during the year 2011. Measurements are presented in the lepton+jets final state, where events are selected by requiring exactly one isolated and highly energetic muon or electron, and at least four jets. In addition the di-lepton final state, consisting of two electrons or muons, at least two jets, and significant missing energy in the transverse plane, is used. First measurements of the cross section for the production of top quark pairs in proton-proton collisions at the LHC in the fully hadronic channel, as well as in final states involving tau leptons, specifically the tau+jets mode and the e-tau / mu-tau dilepton modes are also shown. The results, superseding previous measurements based on 2010 data, are combined and compared with the theory predictions.
        Orateur: Andreas Meyer (DESY)
        Slides
      • 12:00
        Top-quark pair plus photon production at NLO QCD and the top quark electric charge 20m
        I want to discuss the next-to-leading order QCD corrections to the production of a top-quark pair in association with a hard photon. This process allows a direct measurement of the top quark electromagnetic couplings. For a realistic description of this process we incorporated top quark and W-boson decays using the narrow width approximation. Photon radiation off top quark decay products is included and yields a significant contribution to the cross section. I will present our findings for ttbar+gamma production at the Tevatron using the selection criteria of a recent CDF analysis. For the LHC I will discuss the impact of the QCD corrections to the ttbar+gamma process on the measurement of the top quark electric charge.
        Orateur: Dr Andreas Scharf (SUNY Buffalo)
        Slides
      • 12:20
        Top-quark pair production at two loops 20m
        At LHC, top-quark pair production is an important process to test the Standard Model and search for new physics. I discuss an analytical approach to the virtual corrections at NNLO in QCD. Some technical details will be given for the methods employed in the calculation.
        Orateur: Andreas von Manteuffel (University of Zurich)
        Transparents
      • 12:40
        Soft-gluon resummation in top-quark production at hadron colliders 20m
        Techniques and results concerning soft gluon resummation at the level of total and differential cross sections in top-quark pair production at hadron colliders are presented. In particular, the theoretical framework underlying resummation at NLO+NNLL level for differential cross sections is briefly review, and the consequences for observables such as the total inclusive pair-production cross section, the invariant mass and transverse momentum distributions, and the forward-backward asymmetry are discussed.
        Orateur: Ben Pecjak (Johannes Gutenberg-Universitaet Mainz)
        Slides
    • 11:00 13:00
      Ultrarelativistic Heavy Ions Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      Président de session: Dr Alexander Milov (Weizmann Institute of Science)
      • 11:00
        New Theoretical Developments in Medium Modifications of Jets 30m
        The LHC offers unprecedented opportunities to study the jets produced in heavy ion collisions. The release of the first LHC heavy ion data on jets has been accompanied by a surge of related theoretical activity. These recent efforts have focused on the identification and development of necessary ingredients to promote and complement the existing theoretical formulations, originally developed for the study of single parton energy loss in the presence of a medium, to the case of fully reconstructed jets. I will review recent efforts including those to account for the colour flow and the role of colour coherence effects in the parton cascade, and the relevance of transport of soft jet components away from the jet. Whenever appropriate I will discuss the phenomenological implications of these novel effects and discuss their relevance to the understanding of the available data.
        Orateur: Dr Jose Guilherme Milhano (CENTRA-IST, Lisbon & CERN PH-TH)
        Transparents
      • 11:30
        Summary of the latest PHENIX Heavy Ion Results 30m
        The PHENIX Experiment at the Relativistic Heavy Ion Collider of the Brookhaven National Laboratory has been taking data for over 10 years. The accumulated data sets span multiple beam energies and collision systems that provide an increasingly detailed picture of the hot and dense medium produced in central heavy ion collisions. I will summarize our latest results and give an outlook of our future program.
        Orateur: Dr Chris Pinkenburg (BNL)
        Transparents
      • 12:00
        The RHIC Beam Energy Scan 30m
        For almost 30 years, hadron production in heavy ion collisions has been an important observable for probing the state of nuclear matter. Mapping out the phase diagram of strongly interacting matter is a challenging open task in quantum chromodynamics (QCD). The goal of the RHIC $Beam$ $Energy$ $Scan$ program (BES) is to study the phase diagram of strongly interacting matter to search for the critical point (CP) and the onset of deconfinement. Currently the most promising predictions for identifying these phenomena are non-monotonic deviations in the energy dependence of elliptic flow, hadron yield production, and the critical point fluctuations of conserved quantum number like baryon number and strangeness. Furthermore a scan would provide more information about where the constituent quark scaling of elliptic flow will break and can be used as a signature for the onset of deconfinement. We will present recent results on particle yield and spectra, directed ($v_{1}$) and elliptic flow ($v_{2}$), and event-by-event fluctuations at $\sqrt{s_{NN}}$ = 7.7, 11.5, and 39 GeV. The measurements will be compared to measurements at SPS, higher RHIC, and LHC energies, as well as string hadronic and hydrodynamic model calculations.
        Orateur: Dr Michael Mitrovski (STAR Collaboration)
        Transparents
      • 12:30
        Medium Induced Collinear Radiation from Soft Collinear Effective Theory (SCET) 15m
        The propagation of hard partons through the strongly interacting matter created in high energy heavy-ion collisions involves widely separated scales. The methods of Effective Field Theories (EFT) can provide a factorized description at lowest nontrivial order, and a formalism where the correction to this factorization are calculable systematically order by order in the small ratios between the different scales. In this talk I will present our recent results on the calculation of the spectrum of the gluons emitted by the hard parton, where the radiated gluons are collinear with the incoming hard parton and with arbitrary energy (not necessarily much softer than the energy of the hard parton). I will also briefly discuss how to extend the analysis to include the emission of gluons collinear in arbitrary directions and gluons with all the components of their momentum scaling as the medium characteristic energy scale (soft gluons).
        Orateur: M. Francesco D'Eramo (MIT)
        Transparents
      • 12:45
        NA61/SHINE ion program. 15m
        This presentation will summarize status and plans of the NA61/SHINE ion program. The NA61/SHINE at the CERN SPS facility is the successor of the former NA49 experiment. The study of central Pb+Pb collisions by NA49 indicate that the threshold for deconfinement is reached already at the low SPS energies. Theoretical considerations predict that SPS accelerator will cover one of the most interesting regions of the phase diagram (T - $/mi_{B}$) of strongly interacting matter in which a 1-st order phase boundary between hadronic and partonic phases and the critical point are located. The main physics goals of the NA61/SHINE ion program are to study the properties of the onset of deconfinement and to find signatures of the critical point by performing an energy (beam momentum 13A-158A GeV/c) and system size (p+p, p+Pb, Be+Be, Ar+Ca, Xe+La) scan. The successful increase in the event rate will give us a unique possibility to obtain the inclusive and correlated yields of high $p_{T}$ hadrons at 158 GeV/c. The first data for this 2-dimensional scan were taken in 2009 and 2010 for p+p interactions at 13, 20, 31, 40, 80, 158 GeV/c beam momentum. This contribution will summarize physics arguments for the NA61/SHINE ion program, show the detector performance, the current status of the experiment and plans for the next years. The broad physics program of NA61/SHINE experiment includes also a precision measurements of hadron spectra for the T2K neutrino experiment and for the Pierre Auger Observatory and KASCADE cosmic-ray projects. This subjects will be discussed in separate contribution.
        Orateur: Dr Roman Planeta (Institute of Physics Jagiellonian University)
        Slides
    • 13:00 14:30
      Lunch 1h 30m les Ecrins

      les Ecrins

      Alpes Congrès - Alpexpo

      Venue is in room Ecrin at Alpexpo for people having reserved lunches on site.

    • 14:30 16:00
      Astroparticle Physics Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 14:30
        Mini-review Direct Dark Matter Detection and recent XENON100 results 30m
        Orateur: Dr Teresa Marrodán Undagoitia (Universität Zürich)
        Slides
      • 15:00
        Status and prospects of the EDELWEISS direct WIMP search 15m
        EDELWEISS is a direct search for WIMP dark matter using cryogenic heat-and-ionization germanium detectors. We report the final results of the second stage of the experiment, EDELWEISS-II, obtained with an array of ten 400 g detectors equipped with interleaved electrodes for the rejection of surface events. Limits on the elastic and inelastic cross-sections of spin-independent interactions of WIMPs were derived from a total exposure of 384 kg.day, obtained following fourteen months of continuous operation at the Laboratoire Souterrain de Modane. We also present the prospects of EDELWEISS-III, which plans to accumulate more than 3000 kg.day of data with 40 new 800 g detectors. All the surfaces of these new detectors are fully covered with interleaved electrodes, resulting in an increase of fiducial mass and of the rejection capabilities.
        Orateur: Jules Gascon (Universite de Lyon, Universite Lyon 1, CNRS/IN2P3)
        Transparents
      • 15:15
        Direct Dark Matter and Axion Detection with CUORE 15m
        The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment to search for neutrinoless double beta decay in Te-130 and other rare processes. CUORE is a bolometric detector composed of 988 TeO2 crystals, with the total mass of about 1 tonne. The large detector mass, low backgrounds, and the low energy threshold of a few keV make the experiment well suited for direct detection of galactic dark matter particles and solar axions. We discuss the development of a novel low-energy trigger that enables such searches, and present the preliminary results from a test run with four CUORE-like crystals at Gran Sasso National Laboratories in Italy.
        Orateur: Mme Cecilia Maiano (University of Milano Bicocca and INFN, Sezione di Milano-Bicocca)
        Slides
      • 15:30
        From CDMS to SuperCDMS 15m
        The CDMS experiment is a search for dark matter employing subkelvin germanium detectors. A dual phonon-ionization measurement allows to reject the dominant radioactive background. We present results from CDMS and progress towards SuperCDMS. We will also report the result of a joint analysis of CDMS and EDELWEISS data.
        Orateur: Philippe Di Stefano (and the CDMS Collaboration) (Department of Physics, Queen's University)
        Transparents
      • 15:45
        Overview of Searches for Supersymmetry with the ATLAS detector 15m
        ATLAS searches for supersymmetry in data from the 2010 and 2011 running of the LHC will be reviewed. These searches were performed in various channels containing different lepton and jet multiplicities in the final state. Although ATLAS searches for supersymmetry in channels both with and without missing transverse momentum, this talk will concentrate on the missing transverse momentum channels, in order to make the connection with dark matter.
        Orateur: Anyes Taffard
        Slides
    • 14:30 16:00
      Flavour Physics and Fundamental Symmetries Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 14:30
        Radiative flavour violation in the MSSM 15m
        In this talk I review the consequences of radiative flavour violation in the MSSM. Since self-energies can be chirally enhanced and therefore of order one it is possible to generate the light-quark masses and the CKM matrix via loops. In the case of CKM generation in the down-sector constraints from b->s gamma, and in the case of CKM generation in the up-sector from epsilon_K, are observed. In the second case the rare decay K-> pi nu nu receives sizable contributions while in the first case additional contributions to B_s->mu mu via neutral Higgs penguins occur. These Higgs penguins can also contribute to Bs mixing and are capable to explain the observed CP asymmetry. In conclusion I show that for SUSY masses around 1 TeV radiative flavour-violation is an interesting solution to the SUSY flavour and CP problem.
        Orateur: Dr Andreas Crivellin (ITP Bern)
        Slides
      • 14:45
        U(2) and Minimal Flavour Violation in Supersymmetry 15m
        Rather than sticking to the full U(3)^3 approximate symmetry normally invoked in Minimal Flavour Violation, we analyze the consequences on the current flavour data of a suitably broken U(2)^3 symmetry acting on the first two generations of quarks and squarks. A definite correlation emerges between the mixing amplitudes in the K, B_d and B_s systems, which can resolve the current tension in the CKM fit, while predicting the B_s mixing phase. The preferred region for the gluino and the left-handed sbottom masses is below about 1 to 1.5 TeV.
        Orateur: Dr David Straub (Scuola Normale Superiore, Pisa)
        Slides
      • 15:00
        Bs decays at Belle 15m
        Using fully reconstructed $B_{s}$ mesons, we measure the branching fractions for the decays of $B_s \to D_s^{(*)+}D_s^{(*)-}$ exclusively. Assuming these decay modes saturate decays to CP-even final states, the branching fraction determines the relative width difference between the $CP$-odd and $CP$-even $B_s$ states. We study the decay $B^0_s\to J/\psi \phi$, $\phi \to K^+ K^-$. In this sample $B^0_s$ mesons are produced in three $\Upsilon(5S)$ decays: $\Upsilon(5S) \to B^*_s\overline{B}^*_s$, $B^*_s\overline{B}_s$ and $B_s\overline{B}_s$, where the $B^*_s$ mesons decay to $B_s \gamma$. We determine the absolute branching fraction of the decay $B^0_s\rightarrow J/\psi \phi$, which is an important mode for measuring the CP violating phase $\beta_s$ in the $B_s \overline{B}_s$ mixing. The latter is of particular interest as it is sensitive to physics beyond the Standard Model. We also report the first observation of $B_s^0\to J/\psi f_0(980)$ and first evidence for $B_s^0\to J/\psi f_0(1370)$, which are CP-eigenstate decay modes. We measure the branching fractions $\mathcal{B}(B_s^0\to J/\psi f_0(980);f_0(980)\to\pi^+\pi^-)=(1.16^{+0. 31}_{-0.19}(\mathrm{stat.})^{+0.15}_{-0.17}(\mathrm{syst.})^{+0.26}_{-0. 18}(N_{B_s^{(*)}\bar B_s^{(*)}})) \times 10^{-4}$ with a significance of $8.4\sigma$, and $\mathcal{B}(B_s^0\to J/\psi f_0(1370);f_0(1370)\to\pi^+\pi^-)=(0.34 ^{+0.11}_{-0.14}(\mathrm{stat.})^{+0.03}_{-0.02}(\mathrm{syst.})^{+0.08} _{-0.05}(N_{B_s^{(*)}\bar B_s^{(*)}})) \times 10^{-4}$ with a significance of $4.2\sigma$. The last error listed is due to uncertainty in the number of produced $B_s^{(*)}\bar B_s^{(*)}$ pairs. We have also performed the first search for charmed baryonic $B_s^0$ decay, $\bar{B}_s^0\rightarrow\Lambda_c^+\pi^-\bar{\Lambda}$. The measurement precision of the $B_s^0$ branching fraction at Belle is limited by the poor knowledge of the $B_s^0$ production fraction, $f_s=\sigma(B_s^{(\ast)}\bar B_s^{(\ast)})/\sigma(b\bar b)$. We present the status of the current measurements and discuss their main limitations. Using dilepton events, a new independent measurement of $f_s$ is presented, together with its impact on the precision of Belle's $B_s^0$ measurements. We present a measurement of the CP violation parameter sin2$\phi_1$ at the $\Upsilon$(5S) resonance using a new tagging method called the B-$\pi$ tagging. This method in general uses a $\Upsilon$(5S) decay to a charged B meson, a neutral B meson, and a charged pion. The neutral B meson decays to a CP eigenstate, and the charged B meson is reconstructed as missing mass of the neutral B meson and the charged pion. The initial flavor of the neutral B meson is determined by the charge of the pion at the moment of the $\Upsilon$(5S) decay. CP violating parameters can be derived from asymmetry of the number of BB$\pi^+$ and BB$\pi^-$ events without measuring decay time. Since the B-$\pi$ tagging method have different systematic errors from the analyses on the $\Upsilon$(4S) resonance and thus complementary. In this analysis, the neutral B meson is reconstructed as J/$\psi$K$_{\rm S}$. All these results are based on a data sample collected with the Belle detector at the $\Upsilon(5S)$ resonance with an integrated luminosity of 121.4 fb$^{-1}$ at the KEKB asymmetric-energy $e^+ e^-$ collider.
        Orateur: Dr Remi Louvot (EPFL, Lausanne)
        Transparents
      • 15:15
        Measurements of CP violation in the Bs system at D0 15m
        We report a new measurement of the $CP$-violating phase $\phi_s$, of the decay width difference for the two mass eigenstates $\Delta \Gamma_s$, of the mean $B^0_s$ lifetime $\overline{\tau}_s$, and of magnitudes of the decay amplitudes, from the flavor-tagged decay $B^0_s\to J/\psi \phi$. For the first time, we consider possible contributions from the decay $B^0_s \rightarrow J/\psi K^+K^-$, with the $K^+K^-$ in a $s$ wave. This measurement is based on 8 fb$^{-1}$ of $p\overline{p}$ collisions recorded with the D0 detector at a center-of-mass energy $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider. We also present a combination of the constraints on the $B^0_s$ width difference, $\Delta\Gamma_s$, and of the $CP$-violating phase, $\phi_s$ obtained combining with measurement with the results from the search for CP violation in semileptonic $B^0_s\rightarrow\mu^+D^-_sX$ decays, the measurement of the branching ratio for the decay $B^0_s\rightarrow D^{(*)+}_s D^{(*)-}_s$ and the measurement of the like-sign asymmetry for semileptonic $b$ decays. Finally the prospects for including additional information from the $B^0_s\to J/\psi f_0(980)$, $f_0(980)\to\pi^+\pi^-$ decay are also discussed.
        Orateur: Dr Sergey Burdin (University of Liverpool)
        Transparents
      • 15:30
        Anomalous like-sign dimuon charge asymmetry at D0 15m
        We present an improved measurement of the charge asymmetry $A$ of like-sign dimuon events in 9 fb$^{-1}$ of $p\overline{p}$ collisions recorded with the D0 detector at a center-of-mass energy $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider. From $A$, we extract the like-sign dimuon charge asymmetry in semileptonic $b$-hadron decays. We also study the dependence of charge asymmetry on muon impact parameter. Additional constraints on the $CP$ violation in the $B$ meson sector are also derived from a measurement of the flavor-specific semileptonic asymmetry in the $B^0_d\to\mu D+X$ channel.
        Orateur: Guennadi Borissov
        Slides
      • 15:45
        Time dependent CP-violation measurements and related studies in B_s decays at LHCb 15m
        The determination of the CP-violating phase $\phi_s$ in $B^0_s \rightarrow J/\psi \phi$ decays is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model but can be significantly enhanced in many models of new physics. To perform the first LHCb analysis of $\phi_s$ on 2010 data at a centre of mass energy of 7 TeV, many milestones needed to be achieved first, such as for example the measurements of the $B$ hadron lifetimes, the measurement of the polarization amplitudes in $B^0 \rightarrow J/\psi K^*$ decays and the measurement of the CP violation in mixing in $B^0 \rightarrow J/\psi K_s$ decays. We will present our latest result of the $\phi_s$ analysis and related measurements. One of the challenges for all measurement of time dependent asymmetries in the $B_s$ system is to resolve the extremely fast $B_s$ oscillation. Due to its excellent proper time resolution, the LHCb collaboration was able to performed the world most precise $\Delta m_s$ measurement based on a data set of 36 pb$^{-1}$ only. One of the key ingredients to this analysis is the flavour tagging. We will present in this talk the status of opposite and same side flavour tagging and the latest $\Delta m_s$ result. The LHCb collaboration has performed a first analysis of the CP-violating phase $\phi_s$ in tree dominated $B^0_s \rightarrow J/\psi \phi$ decays exploiting an angular analysis to separate CP even and CP odd eigenstates. Additional modes have been studied for complementary analysis, e.g. by using penguin decays or by using decays to CP eigenstates. In this talk we will present the first observation of the decay $B_s \rightarrow J/Psi f_0$ and of $B_s \rightarrow K^*\overline{K^*}$. The potential of these decays an other alternative $B_s$ modes to study CP violation in mixing will be discussed. We investigate the resonance structure in the pi+pi- system produced in B_s -> J/psipi+pi- decays. Such decays can be used to measure the CP violating phase in B_s decays. This ?final state is known to have large component of scalar f0(980) and a spectrum of additional events at higher masses. While the f0(980) part is a CP eigenstate, higher mass states could also be scalars and be simply added into the analysis. Using pp collisions at 7 TeV centre-of-mass energy collected by the LHCb detector, the angular distributions of the decays are analyzed and the spin-parity of the various components is determined.
        Orateur: M. Christian Linn
        Transparents
    • 14:30 16:00
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 14:30
        A search for charged massive long-lived particles at D0 15m
        We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb$^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. CMLLPs are predicted in many theories of physics beyond the Standard Model. We look for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss $dE/dx$ inconsistent with muons produced in beam collisions. We present 95\% C.L. upper limits on the production cross section for $\tilde{\tau}$ and exclusion mass ranges for $\tilde{\chi}^{\pm}$ in two SUSY scenarios and for long-lived $\tilde{t}$ squarks.
        Orateur: Prof. Sudeshna Banerjee (Tata Institute of Fundamental Research)
        Transparents
      • 14:45
        Searches with top quarks at D0 15m
        We present two searches involving final states with top quarks or with topologies similar to those observed in top quark decays. The first is a search for the pair production of a fourth generation $t'$ quark and its antiparticle, followed by their decay to a W boson and a jet, based on an integrated luminosity of 5.3 fb$^{-1}$ of $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV. The second is a search for the production of a heavy gauge boson $W'$, that decays to third generation quarks. In both cases we set 95\% C.L.~upper limits on the production cross sections and translate these into limits on the mass of the fourth generation quarks oir of the $W'$ boson in a variety of models.
        Orateur: Prof. Dhiman Chakraborty (Northern Illinois University)
        Slides
      • 15:00
        Searches for new physics at HERA (H1) 15m
        New results on searches at HERA with the H1 Experiment are presented.
        Orateur: M. Hayk Pirumov (PI Heidelberg)
        Slides
      • 15:15
        Search for physics beyond the SM in ep collisions at HERA 15m
        Various channels were explored to look for physics beyond the standard model. A search for first generation leptoquarks as a unique signal for new physics was augmented by searches for unnaturally large number of events in channels where the number of events predicted in the SM is small. Such a channel is the production of single top. Another such channel is the production of tau pairs. Limits are presented and SM quantities are evaluated in the absence of an indidcation of new physics.
        Orateur: Lorenzo Bellagamba
        Slides
      • 15:30
        Higgs searches 30m
        Higgs searches
        Orateur: Margarete Muehlleitner
        Transparents
    • 14:30 16:00
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 14:30
        High Q2 Neutral and Charged Current in polarised collisions at HERA II with H1 15m
        The inclusive single differential cross section $d\sigma/dQ2$ and the reduced double differential cross section $\tilde{\sigma}(x,Q2)$ are presented for neutral and charged current processes, $e^{\pm}p \rightarrow \nu X$, in interactions with longitudinally polarised lepton beams using the complete HERA-II data set. The cross sections are measured in the region of large negative four-momentum transfer squared $Q2 \geq 200$ GeV$^2$ and inelasticity $y<0.9$. Together with the corresponding cross section obtained from the previously published unpolarised data, the polarisation dependence of the charged current cross section is measured and found to be in agreement with the Standard Model prediction. The neutral current data are consistent with the expected $Q2$ dependence of polarised cross sections. The data are compared to predictions of the Standard Model which is able to provide a good description of the data.
        Orateur: Shiraz Habib
        Slides
      • 14:45
        Inclusive e-p cross sections at HERA and determinations of F_L 15m
        A combination of the inclusive cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current deep-inelastic ep scattering at HERA is presented. The combination uses data from unpolarised ep scattering taken during the HERA-I phase as well as measurements with longitudinally polarised electron or positron beams from the HERA-II running period. The combination method takes the correlations of systematic uncertainties into account. The inclusion of the large HERA-II data set leads to an improved uncertainty especially at large four momentum transfer squared Q2. A combination is presented of the inclusive deep inelastic cross sections measured in neutral and charged current unpolarised $e^{\pm}p$ scattering at HERA during the period $1994$-$2000$. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions HERAPDF1.0 with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result. A combination of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations for ep scattering with nominal and reduced proton-beam energies, Ep=920 GeV, Ep=460 GeV and 575 GeV, is presented. The combination method used takes the correlations of systematic uncertainties into account, resulting in improved accuracy. From the combined data the proton structure function, FL, is extracted in the region of 2.5<800 GeV2. Finally, a measurement is presented of the inclusive neutral current e\pm p scattering cross section using data collected by the H1 experiment at HERA during the years 2003 to 2007 with proton beam energies Ep of 920, 575, and 460 GeV. The kinematic range of the measurement covers low absolute four-momentum transfers squared, 1.5 GeV2 < Q2 < 120 GeV2, small values of Bjorken x, 2.9 \cdot 10-5 < x < 0.01, and extends to high inelasticity up to y = 0.85. The structure function FL is measured by combining the new results with previously published H1 data at Ep = 920 GeV and Ep = 820 GeV. The new measurements are used to test several phenomenological and QCD models applicable in this low Q2 and low x kinematic domain.
        Orateur: Vladimir Chekelian
        Slides
      • 15:00
        Nuclear corrections in neutrino--nucleus DIS and their compatibility with global NPDF analysis 15m
        We perform a global chi^2-analysis of nuclear parton distribution functions using data from charged current neutrino-nucleus deep-inelastic scattering (DIS), charged-lepton-nucleus DIS, and the Drell-Yan (DY) process. We show that the nuclear corrections in nu-A DIS are not compatible with the predictions derived from l^+A DIS and DY data. We quantify this result using a hypothesis-testing criterion based on the chi^2 distribution which we apply to the total chi^2 as well as to the chi^2 of the individual data sets. We find that it is not possible to accommodate the data from nu-A and l^+A DIS by an acceptable combined fit. Our result has strong implications for the extraction of both nuclear and proton parton distribution functions using combined neutrino and charged-lepton data sets.
        Orateur: Dr Ji Young Yu (LPSC)
        Transparents
      • 15:15
        Diffractive structure functions and extraction of PDFs with H1 15m
        In 2004, the H1 Collaboration at HERA installed the Very Forward Proton Spectrometer (VFPS) located at 220m from the interaction point, in the cold section of the proton ring. The spectrometer consists of two Roman Pot stations equipped with scintillating fiber detectors. The device allows the measurement of diffractive proton momentum in the range 0.009 < xpom < 0.025, where xpom is the energy fraction lost by the proton in the interaction, with a very high acceptance (above 90%). The inclusive diffractive deep inelastic scattering, ep -> e gamma* p -> e X p, has been measured with the H1 detector at HERA using VFPS to measure the scattered proton momentum. The cross section is measured differentially in Q2, xpom and beta and compared to previously measured cross section at HERA. A measurement of the longitudinal diffractive structure function F_L^D at low Q2 is also presented. Measurements of the diffractive cross-section at centre of mass energies \sqrt{s} of 225 and 252 GeV in the Q2 range of [2.5; 7] GeV2, using HERA data taken in 2007, are combined with a published measurement at $\sqrt{s}$ of 300 GeV. The structure function F_L^D is extracted from these cross-sections at high values of inelasticity y. Measurements of the cross section for the diffractive process ep -> eXY are also presented, where Y is a proton or a low mass proton excitation carrying a fraction 1-x_IP > 0.95 of the incident proton longitudinal momentum and the squared four-momentum transfer at the proton vertex satisfies |t| < 1.0 GeV2. The cross section is measured for photon virtuality in the range 3.5 < Q2 < 90 GeV2, triple differentially in x_IP , Q2 and beta=x/x_IP , where x is the Bjorken scaling variable. These measurements are done after selecting diffractive events showing a large rapidity interval between the hadronic systems X and Y. Recent H1 measurements of the diffractive DIS cross section based on the reconstruction of a large rapidity gap or the detection of the scattered proton in the FPS or VFPS detectors have been used to extract a new set of diffractive parton distribution functions. The NLO QCD fit fully exploits the possibility that, according to the DDIS factorisation theorem which holds at fixed x_pom, the parton content of the colourless exchange may depend continuously on the x_pom variable. In particular the new fitting strategy does not assume proton vertex factorisation nor inputs from Regge theory in its x_pom dependence.
        Orateur: Paul Laycock
        Slides
      • 15:30
        Quantifying the impact of collider isolated photon data on global PDF fits 15m
        Isolated prompt photon production in proton-(anti)proton collisions proceeds mostly through quark-gluon Compton scattering [1] and has been proposed since long to directly constrain the gluon distribution in the proton. There exist 25 pT-differential measurements of isolated photon production at collider energies in the range sqrt(s)=0.2-7 TeV which are well reproduced by next-to-leading-order (NLO) perturbative QCD predictions, yet the photon data have not been included in global parton distribution functions (PDF) fits since more than 10 years. We present a quantitative study of the impact of including these data sets into global PDF fits based on the JETPHOX NLO code [2] supplemented with the NNPDF2.1 parton densities [3]. By running over hundreds of PDF replicas and using the NNPDF reweighting technique [4] we quantify the additional constraints that all these data (and coming LHC measurements) will impose on the gluon distribution of the proton. [1] R.Ichou and D.d'Enterria, Phys.Rev.D82(2010)014015;arXiv:1005.4529 [2] S.Catani, M.Fontannaz, J.P.Guillet, E.Pilon, JHEP 0205(2002)028;hep-ph/0204023 [3] R.D. Ball et al. [NNPDF Coll.], Nucl.Phys.B849(2011)296; arXiv:1101.1300 [4] R.D. Ball et al. [NNPDF Coll.], Nucl.Phys.B849(2011)112; arXiv:1012.0836
        Orateur: Prof. David d'Enterria (CERN)
        Slides
      • 15:45
        ATLAS studies of Soft QCD Processes at 7 TeV 15m
        Using Minimum Bias data recorded in 2010, ATLAS has carried out several studies of the global properties of pp collisions at 7 TeV. A precise measurement of the total inelastic cross-section is presented in a well-defined fiducial volume, taking advantage of the precise knowledge of the luminosity available from van der Meer scans First detailed studies of diffraction cross-sections are also reported, based on pseudo-rapidity gap distributions. The fraction of the inelastic cross-section arising from diffractive processes is studied, and the differential cross-section is measured as a function of gap size.
        Orateur: Dresden Deepak Kar
        Slides
    • 14:30 16:00
      Top and Electroweak Physics Stendhal (Universe)

      Stendhal

      Universe

      Président de session: Marjorie Shapiro (LBL)
      • 14:30
        Measurement of the top-quark pair production cross section in ATLAS 30m
        We present measurements of the top-quark pair-production in proton-proton collisions at sqrt(s)= 7 TeV with the ATLAS detector at the Large Hadron Collider. The cross section is measured in several channels, including the single lepton, dilepton and all hadronic channel, some using information from b-tagging.
        Orateur: Maria Jose Costa
        Slides
      • 15:00
        Precise measurements of the top mass and direct measurement of the mass difference between top and antitop quarks at D0 30m
        We report on measurements of the top quark mass using dilepton and lepton+jet data collected with the D0 detector. These results are compared to the top mass extracted from the $t\bar{t}$ cross section using higher-order quantum chromodynamics calculations. We also present a direct measurement of the mass difference between top and antitop quarks ($\Delta m$) in lepton+jets $t\bar{t}$ final states using the “matrix element” method.
        Orateur: Gianluca Petrillo (University of Rochester)
        Transparents
      • 15:30
        Measurement of Top Quark Pair Production and Decay Properties in pp collisions at 7 TeV using the CMS detector 15m
        We present measurements of various differential cross sections in top pair production in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. We use data collected by the CMS experiment during the year 2011. Cross sections are measured differentially as a function of various variables. We also present a measurement of the charge asymmetry in top-pair production. In order to measure the charge asymmetry in charge-symmetric initial state processes, the difference of absolute pseudo rapidities of top and anti-top is used. The results are compared with various theory predictions, and discussed in the context of forward-backward asymmetry measurements at Tevatron.
        Orateur: Dr Amanda Deisher (UCLA/ETH)
        Slides
      • 15:45
        Top quark mass measurement in ATLAS 15m
        We present a measurement of the top-quark mass in proton-proton collisions at = 7 TeV with the ATLAS detector at the Large Hadron Collider. The top mass is extracted directly in the single lepton channel with template methods and indirectly from the measurement of the production cross-section.
        Orateur: Dr Anne-Isabelle ETIENVRE (CEA-DAPNIA)
        Transparents
    • 14:30 16:00
      Ultrarelativistic Heavy Ions Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      Président de session: Dr Boris Hippolyte (IPHC Strasburg)
      • 14:30
        Initial conditions in heavy ion collisions: from RHIC to the LHC 30m
        I will present a brief review of the different approaches to the description of bulk particle production in heavy ion collisions at RHIC and the LHC, with emphasis in the Color Glass Condensate approach (CGC). In the CGC approach coherence effects are taken into account through non-linear QCD renormalization group equations and also in the use of semi-classical methods appropriate at high gluon densities. Recent improvements in the phenomenological implementations of CGC ideas, such as inclusion of running coupling correctionsor the use of Monte Carlo techniques, allow for a consistent, unified description of data from different systems: from e+p to A+A collisions, including latest LHC data.
        Orateur: Dr Javier L. Albacete (Universidade de Santiago de Compostela)
        Transparents
      • 15:00
        First results on the event-by-event fluctuations and correlations in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$~TeV 15m
        Fluctuations of thermodynamic quantities are fundamental for the study of the QGP phase transition. Among the several observables calculated on an event-by-event basis, the different measures of the charge and mean transverse momentum fluctuations are of particular interest since they are considered to be indicators of the existence and of the order of this transition as well as of the thermalization in central A-A events. We will review the first results from the event-by-event physics program of the ALICE experiment in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$~TeV. The experimental results will be compared to previously published data and available model predictions. The implications of the evolution of the fluctuations after the hadronization will be discussed and quantified.
        Orateur: Dr Panos Christakoglou (NIKHEF)
        Transparents
      • 15:15
        Measurements of Higher-Order Flow Harmonics at PHENIX 15m
        Measurement of anisotropic particle production transverse to the beam direction, referred to as collective flow, has provided a powerful tool for characterizing ultrarelativistic heavy-ion collisions. We will present recent results on higher-order flow harmonics for different particle species at various Au+Au collision energies measured with the PHENIX experiment at the Relativistic Heavy Ion Collider. Through comparison of our flow measurements to hydrodynamic models, we derive constraints on the properties that characterize the strongly-coupled quark gluon plasma created during these collisions.
        Orateur: Dr Robert Pak (Brookhaven National Laboratory)
        Slides
      • 15:30
        Three-dimensional Kaon Source Imaging from STAR Experiment at RHIC 15m
        Three-dimensional source imaging techniques in conjunction with detailed model comparisons have shown the viability of disentangling the spatio-temporal information contained in two-pion interferometric measurements from ultra-relativistic heavy ion collisions. This has led to the observation of non-Gaussian tails in the 3D pion source function and the extraction of finite pion emission duration at RHIC energies. The STAR Collaboration has recently also extracted the 3D kaon source function from a high statistics two-kaon interferometric measurement from Au+Au collisions at sqrt_sNN = 200 GeV. Such measurement offers a window into the fireball freeze-out dynamics with a much cleaner probe with smaller resonance decay contributions than for the pion case. The extracted space-time characteristics are compared with those obtained from pion analysis. The implications with respect to the validity of the Buda-Lund hydrodynamic expansion scenario are discussed.
        Orateur: Dr Michal Sumbera (Nuclear Physics Institute ASCR)
        Transparents
      • 15:45
        Transverse momentum spectra of identified charged hadrons with the ALICE detector in PbPb collisions at the LHC 15m
        The measurement of identified charged hadron production at mid-rapidity (|y| < 0.5) performed with the ALICE experiment is resented for PbPb collisions at a nucleon-nucleon c.m. energy of 2.76 TeV. The transverse momentum spectra of charged pions, kaons, protons and antiprotons are measured from 200 MeV/c up to 3 GeV/c for pions and kaons and from 400 MeV/c up to 5 GeV/c for protons and antiprotons using the dE/dx and the time-of-flight particle-identification techniques. Preliminary results on charged hadron production yields and particle ratios are reported as a function of pT and collision centrality. Finally, the results are discussed in terms of hydrodynamics-inspired models and compared with published RHIC data in Au泡u collisions at c.m. energy of 200 GeV per nucleon pair and Monte Carlo predictions.
        Orateur: Dr Roberto Preghenella (INFN Bologna)
        Transparents
    • 16:00 16:30
      Tea 30m Lobby

      Lobby

      Alpes Congrès - Alpexpo

    • 16:30 18:30
      Astroparticle Physics les Ecrins 3

      les Ecrins 3

      Alpes Congrès - Alpexpo

      • 16:30
        Indirect Detection Dark Matter Searches Mini-review 30m
        The self-annihilation, or decay, of dark matter particles could result in significant contributions to cosmic ray fluxes of various kinds, providing a unique opportunity to detect dark matter by means other than through its gravitational interaction. A wealth of observational data, both existing and upcoming, makes these indirect detection channels ever more interesting. I review the various messengers used in indirect dark matter searches and compare their respective advantages and disadvantages. I also briefly comment on the complementarity between indirect and direct detection methods, where one hopes to observe the recoil energy that dark matter particles would cause when interacting with a terrestrial detector.
        Orateur: Torsten Bringmann Bringmann (Hamburg University)
        Slides
      • 17:00
        Radio signals of particle dark matter 15m
        In most of particle dark matter (DM) models, the DM candidate injects sizable fluxes of high-energy electrons and positrons through its annihilations or decays. Emitted in regions with magnetic field, they in turn give raise to a synchrotron radiation, which typically covers radio and infrared bands. We discuss the possibility of detecting signatures of Galactic and extra-galactic DM in the isotropic total intensity and small-scale anisotropies of the radio background.
        Orateur: Dr Marco Regis (University of Turin and INFN)
        Slides
      • 17:30
        Indirect searches for Dark Matter with the ANTARES neutrino telescope 15m
        Using the ANTARES neutrino telescope, the largest neutrino telescope in the Northern hemisphere, with its first configuration with 5 lines of photodetectors to the actual nominal one corresponding to a total of 12 lines, we have studied our ability to search indirectly for an evidence of Dark Matter annihilations in heavy astrophysical objects as the Sun and the Galactic centre. First results have been obtained using the data recorded by ANTARES in 2007 and 2008, and compared with neutrino fluxes predicted within a minimal supersymmetric extension of the Standard Model with supersymmetry-breaking scalar and gaugino masses constrained to be universal at the GUT scale, the CMSSM, as well as a minimal Universal Extra-Dimensions scenario with one extra compact dimension where all the Standard Model fields propagate into the bulk, the UED. The current limits over the neutrino/muon fluxes coming from Dark Matter annihilations, and the spin-dependent cross-section with protons, as well as the expected sensitivities predicted after several years of data taking with ANTARES will be presented for each source.
        Orateur: Dr Guillaume Lambard (IFIC)
        Transparents
      • 17:45
        Probing annihilations and decays of low-mass galactic dark matter by track and cascade events in IceCube DeepCore 15m
        The deployment of DeepCore array significantly lowers IceCube’s energy threshold to about 10 GeV and enhances the sensitivity of detecting neutrinos from annihilations and decays of light dark matter. To match this experimental development, we provide a complete analysis of track and cascade event rates in DeepCore array due to neutrino flux produced by annihilations and decays of galactic dark matter. We also calculate the background event rates due to atmospheric neutrino flux for evaluating the sensitivity of DeepCore array to galactic dark matter signatures. Unlike previous approaches, which set the energy threshold for track and cascade events at around 50 GeV (this choice makes the estimation of atmospheric background event rate much simpler, i.e., the oscillation effect in atmospheric neutrino flux can be neglected), we have set the energy threshold at 10 GeV to take the full advantage of DeepCore array. We compare our calculated sensitivity with those obtained by setting a 50 GeV threshold energy. We conclude that our choice of threshold energy significantly improves the sensitivity to dark matter signature for WIMP mass below 100 GeV.
        Orateur: Dr Fei-Fan Lee (National Chiao Tung University)
        Slides
      • 18:00
        Pamela main results after 5 years of data taking 15m
        The PAMELA satellite-borne experiment was launched from the Bajkonur cosmodrome in June 2006. The combination of a permanent magnet silicon strip spectrometer and a silicon-tungsten imaging calorimeter allows precision studies of the charged cosmic rays to be conducted over a wide energy range with high statistics. After five years of successfully operation in space, the data gathered by the PAMELA experiment are showing very interesting features in cosmic rays spectra, namely in the fluxes of protons, heliums and electrons, that may challenge the current paradigm of cosmic-ray acceleration and propagation in the Galaxy. In addition, PAMELA measurements of cosmic antiproton and positron fluxes are setting strong constraints to the nature of Dark Matter. This talk illustrates the most recent scientific results obtained by the PAMELA experiment.
        Orateur: Oscar Adriani (University of Florence and INFN Sez. di Firemze)
        Slides
      • 18:15
        AMS-2 Status and Updates 15m
        Orateur: Bruna Bertucci
        Slides
    • 16:30 18:30
      Flavour Physics and Fundamental Symmetries Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 16:30
        Hadronic matrix elements for exclusive rare $B$ decays 15m
        I will report on the QCD calculation of the hadronic matrix elements relevant for the exclusive rare $B$ decays, such as $B\to K^{(*)}\ell^+\ell^-$ and $B\to K^*\gamma$. The hadronic input for the decay observables, in addition to the heavy-light form factors, contains specific contributions, generated by the four-quark and penguin operators, such as the charm-loop effects. The corresponding hadronic matrix elements are calculated by the same method as the form factors, applying OPE and light-cone sum rules in QCD. This technique allows one to take into account the nonfactorizable soft-gluon contributions. The results are expressed in terms of (process-dependent) corrections to the short-distance coefficients of the effective Hamiltonian. The impact of these corrections on the most important observables, e.g., on the forward-backward asymmetry in $B\to K^* \ell^+\ell^-$, is estimated.
        Orateur: M. Alexander Khodjamirian (Siegen University)
        Transparents
      • 16:45
        b-quark mass and B decay constant from Nf=2 lattice QCD simulations. 15m
        Precision tests of the Standard Model as well as several New Physics scenarios in the beauty flavour physics are possible, due to the large amount of experimental data already available now and to come in the future. While the theoretical uncertainty is limiting the significance of such tests, lattice QCD offers a powerful approach to compute the necessary non-perturbative hadronic contributions. We report on the status of the ALPHA Collaboration project of lattice Heavy Quark Effective Theory applied to these problems. In a first step the b quark mass and the B decay constant are computed with the effect of Nf=2 dynamical quarks taken into account. The heavy quark is described by HQET (including all effects of order 1/mb) in order to keep the cut-off effects under control. Coefficients of the effective theory have been determined non-perturbatively. Hadronic matrix elements are obtained by solving a Generalised Eigenvalue Problem on a matrix of 2-point correlators. We have considered several lattice spacings and sea quark masses to deal with cut-off effects and chiral extrapolation.
        Orateur: Benoit Blossier (CNRS)
        Slides
      • 17:00
        Heavy-quark masses and heavy-meson decay constants from QCD sum rules 15m
        We present the sum-rule extraction of the decay constants of the D, Ds, B, and Bs mesons from the two-point correlator of heavy-light pseudoscalar currents. We use the OPE of this correlator in terms of the running heavy-quark mass, for which the perturbative expansion exhibits a reasonable convergence. Our main emphasis is laid on the control over the uncertainties in the decay constants, related both to the input QCD parameters and to the limited accuracy of the method of sum-rules. The latter becomes possible due to the application of our procedure of extracting hadron observables that involves as novel feature dual thresholds depending on the Borel parameter. Our results for the decay constants contain the full analysis of both the statistical and systematic uncertainties.
        Orateur: Dr Dmitri Melikhov (HEPHY, Vienna & SINP, Moscow)
        Transparents
      • 17:15
        Exclusive B-Decays in ATLAS 15m
        The ATLAS B physics program relies on exclusive decays, in particular involving a J/\psi. ATLAS capabilities to reconstruct the properties of D-mesons and B-hadrons in exclusive decay modes will be demonstrated and prospects for future measurements highlighted.
        Orateur: Alessandro Cerri
      • 17:30
        Semileptonic B and Charm Decays with BABAR 15m
        We present recent results of studies of semileptonic B and charm decays from BABAR. In particular, we describe a recent measurement of the B-> D(*)tau nu branching fraction, and a study of Bs production and semileptonic decays using BABAR data collected above the Upsilon(4S). We also discuss the determination of |Vub| from exclusive B->pi/rho l nu and and from fully inclusive measurements and present recent branching fraction measurements of B->Lamdba_c p X l nu, B -> Ds K l nu and D+->K-pi+ e nu.
        Orateur: M. Manuel Franco Sevilla
        Slides
      • 17:45
        Recent BABAR measurements of hadronic B branching fractions 15m
        We report on recent results of measurements of hadronic B decay branching fractions from BABAR. These results include B0->D(*)0h0 (where h0 is a neutral hadron), B->D(*)D(*)K, B->D(*)ppbar and B->D(*)0Ks0.
        Orateur: M. Alessandro Gaz
        Slides
      • 18:00
        Exclusive (semi-)leptonic B meson decays at Belle 15m
        We report a search for $B$ decays into invisible final states. The signal is identified by fully reconstructing the accompanying $B$ meson and requiring no other charged particles and no extra energy deposited in the calorimeter. The upper limit obtained will be reported and the corresponding physics will be discussed. We report measurements of the $B \to D_{s}^{(*)} K \ell \nu$ decay branching fractions and of the characteristics of the $D_{s}^{(*)}K$ system. We report a measurement of $B \to \tau \nu$ decays. A sample of $B\bar B $ pair events are tagged by reconstructing one $B$ meson decaying to hadronic final states. We obtain the branching fraction of $B\to\tau\nu$ and present a direct determination of the product of the $B$ meson decay constant $f _{B}$ and the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ub} $. We also discuss constraints on the charged Higgs. The branching fractions of the purely leptonic decays $B^+ \to \ell^+ \nu_{\ell}$, ($\ell= e$, $\mu$) are expected to be very small due to helicity suppression in the Standard Model. With contributions from new physics beyond the Standard Model, helicity suppression may be avoided. Moreover, these modes have a very clean experimental signature. In this study, we present a search for $B^+ \to \ell^+ \nu_{\ell}$ decays using the hadronic $B$-meson tagging method, where a novel technique of neural-network-based $B$-meson tagging method is applied for the optimal background suppression. We also report a study of the charmless semileptonic B-meson decays $B^+ \to \eta \ell^+ \nu$ and $B^+ \to \eta^{\prime} \ell^+ \nu$, in events in which the decay of one $B$ meson is fully reconstructed in an hadronic final state. These results are obtained from the large data sample collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.
        Orateur: Dr Phillip Urquijo Urquijo (University of Bonn)
        Slides
      • 18:15
        Hadronic and semileptonic b-hadron decays at LHCb 15m
        In a data sample corresponding to ∼36 pb−1 of pp collisions at a centre-of-mass energy sqrt(s) = 7 TeV, we make the first observation of the decay Lambda_b -> Lambda_c+Ds- and measure its branching fraction relative to that of Lambda_b -> Lambda_c+π-. We also present related measurements of B hadron decays. In a data sample corresponding to ∼36 pb−1 of pp collisions at a centre-of-mass energy sqrt(s) = 7 TeV, we observe for the first time the decay Bs -> D0 K∗0. A clear signal of 34.5 ± 6.9 events is obtained with a statistical significance over 9 standard deviations and we measure its branching ratio relative to that of B0 → D0 rho0: B(Bs -> D0K∗0)/B(B0 ->D0 rho0) = 1.39 \pm 0.31 \pm 0.17 \pm 0.18, where the first uncertainty is statistical, the second systematic and the third is due to uncertainty in the hadronisation fraction fd/fs. We report first observations of the Cabibbo-suppressed decays B^{-,0} -> D^{0,-}Kππ, and measure their branching fractions relative to the B^{-,0} → D^{0,-}πππ Cabibbo-favoured modes. The measurements are conducted with the LHCb experiment using 35 pb−1 of data collected at sqrt(s) = 7 TeV. The LHCb experiment is pursuing a broad programme of measurements of $B_S$ and $\Lb$ semileptonic decays, with the goal of identifying exclusive hadronic final states and measuring their form factor shapes. We report first measurements of $B_S \to D_S\mu \nu X$, $B_S\to DK\mu\nu X$, and $\Lambda_b\to \Lambda _c \mu\nu X$ based on the 2010 and early 2011 LHCb data samples.
        Orateur: Mme Marina Artuso
        Slides
    • 16:30 18:30
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 16:30
        Light Higgs searches with N-subjettiness 15m
        We introduce a jet shape observable, N-subjettiness, that helps to discriminate the fat jet from a highly boosted color singlet particle decaying to N partons and the QCD jet. As an illustration, a toy scheme for the light Standard Model Higgs search via fully hadronic decay channels from `pp -> H W/Z' is suggested. Issues regarding the subjet definition as required by the N-subjettiness are discussed for both the SISCone and the anti-kT jet algorithm.
        Orateur: M. Jihun Kim (Seoul National Univerity)
        Slides
      • 16:45
        Measurement of diboson production in lepton plus jets decays at the Tevatron 15m
        We present the result of measurements of the cross sections for the simultaneous production of two vector bosons ($WW$, $WZ$, $ZZ$) in lepton plus jets decays at a center-of-mass energy of $\sqrt{s}=1.96$ TeV using data collected with the CDF and D0 detectors at the Fermilab Tevatron. We then present the results of searches for the $WZ$ or $ZZ$ production where one ot the bosons decays leptonically ($W\to\ell\nu$, $Z\to\ell^+\ell^-$ or $Z\to\nu\bar{\nu}$) and the other $Z$ boson decays to $b\bar{b}$. These final states are direct analogs of the final states used in the Standard Model Higgs searches in final states with leptons and $b$ quark pairs and thuis provide a crucial validation benchmark of the Higgs boson signal isolation techniques involved.
        Orateur: M. Thibault Guillemin (LAPP)
        Transparents
      • 17:00
        Search for the Higgs boson in the W+W- decay at Tevatron 20m
        We present the result of searches for the Standard Model Higgs boson produced via the $H\to W W^{(*)}\to\ell^+\ell'^-$ ($\ell,\ell'=e,\mu,\tau$) process at a center-of-mass energy of $\sqrt{s}=1.96$ TeV with the CDF and D0 detectors at the Fermilab Tevatron collider. A Higgs particle with a mass greater than 140 GeV decays primarily into a pair of $W$-bosons and the leptonic decay channels of the $W$ provide a clear signature. This decay channel provides the highest sensitivity to the Higgs boson at the Tevatron and sensitivity to the Standard Model Higgs boson is expected with the dataset considered in these analyses, corresponding to integrated luminosities of up to 8.9 fb$^{-1}$. Recent improvements to the sensitivity will be discussed.
        Orateur: Boris Tuchming (Saclay)
        Transparents
      • 17:20
        Other searches for a high mass Higgs boson at Tevatron. 15m
        We present the result of searches for the Standard Model Higgs boson at the Tevatron in channels which provide additional sensitivity in the high mass region. These include specialized searches for the $H\to W W^{(*)}\to\ell^+\ell'^-$ associated production with a $W$ or a $Z$ boson, resulting in three-leptons final states, searches for the $H\to W W^{(*)}$ decay in final states with 2 jets, a lepton and missing transverse energy, and searches for the $H\to Z Z^{(*)}$ decay in final states with four leptons or two leptons and two jets. These searches complement the main search channel $H\to W W^{(*)}\to\ell^+\ell'^-$.
        Orateur: Dr Antonio Limosani (University of Melbourne)
        Slides
      • 17:35
        NLO QCD and electroweak corrections to Higgs strahlung off W/Z bosons at Tevatron and the LHC with HAWK 15m
        Higgs strahlung off W/Z bosons at Tevatron and the LHC, ppbar/pp -> WH/ZH, is an important process class for discovering a light Higgs boson. In the talk, first results on electroweak (and QCD) corrections for these reactions are shown that support the full differential information and the decays of the W/Z bosons, i.e. the actually considered processes are ppbar/pp -> l nu H / l l H. The precise knowledge of differential distributions is particularly important in view of the fact that reconstructing Higgs strahlung at the LHC has to proceed via the investigation of "fat b jets" of highly boosted Higgs bosons and that electroweak corrections usually show strong variations in transverse-momentum distributions. Both results and details of the calculation, which is embedded in the HAWK Monte Carlo generator first designed for Higgs production via vector-boson fusion, are presented.
        Orateur: Prof. Stefan Dittmaier Dittmaier (University of Freiburg)
        Slides
      • 17:50
        Search for the Standard Model Higgs boson in final states with b quarks at the Tevatron 20m
        We present the result of searches for a low mass Standard Model Higgs boson produced in association with a $W$ or a $Z$ boson at a center-of-mass energy of $\sqrt{s}=$1.96~TeV with the CDF and D0 detectors at the Fermilab Tevatron collider. The search is performed in events containing one or two $b$-tagged jets in association with either two leptons, or one lepton and an imbalance in transverse energy, or simply a large imbalance in transverse energy. Datasets corresponding to up to 8.5~fb$^{-1}$ of integrated luminosity are considered in the analyses. These are the most powerful channels in the search for a low mass Higgs boson at the Tevatron. Recent sensitivity improvements will be discussed.
        Orateur: Karolos Potamianos
        Slides
      • 18:10
        Search for the Standard Model Higgs boson in final states with photons or taus at the Tevatron 15m
        Although the sensitivity to a low mass Standard Model Higgs boson at the Fermilab Tevatron is highest for channels involving the $H\to b\bar{b}$ decay, other channels contribute significantly to the combined Higgs search. We report the results of searches for the Higgs boson in the diphoton final state using up to 8.5~fb$^{-1}$ of integrated luminosity collected by the CDF and D0 detectors at $\sqrt{s}=1.96$ TeV. Both gluon fusion and associated production processes are exploited. Whilst the branching ratio to the diphoton final state is small in the Standard Model, this channel contributes appreciably to the overall Higgs sensitivity at the Tevatron. Combined limits from the Tevatron experiment for this channel are presented and the result of these searches are also interpreted in fermiophobic models where the diphoton branching ratio is considerably larger. In addition we present the results of searches in final states with two taus and two jets. These final states are sensitive to a combination of associated production, gluon-gluon fusion and vector boson fusion production processes and further enhance the sensitivity to the Standard Model Higgs boson.
        Orateur: Azeddine Kasmi
        Transparents
    • 16:30 18:30
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 16:30
        Heavy flavour production measurements in p-p collisions at the LHC with ALICE 15m
        The measurement of heavy flavour production in proton-proton collisions at the LHC allows to study the production mechanisms and to test perturbative Quantum Chromodynamics at a new energy domain. Furthermore, it will provide important reference for investigations of medium effects in Pb-Pb collisions, where charm and beauty are regarded as a good probe for parton-medium interaction dynamics. Open heavy flavour production can be measured through hadronic D meson decays at central rapidity and semi-leptonic D and B meson decays at central and forward rapidities by the ALICE experiment. We present preliminary results of these studies in p-p collisions at sqrt(s) = 2.76 and 7 TeV and compare these to pQCD predictions. The cross section measurements of J/psi production in the di-electron channel at central rapidity and in the di-muon channel at forward rapidity will be discussed as well.
        Orateur: Dr Yvonne Pachmayer (University of Heidelberg)
        Transparents
      • 16:45
        Measurements of B-quark production at 7 TeV with the CMS experiment 15m
        Measurements performed by the CMS experiment of the cross section for inclusive b-quark production in proton-proton collisions at \sqrt(s) = 7 TeV are presented. The measurements are based on different methods, such as inclusive jet measurements with secondary vertex tagging or selecting a sample of events containing jets and at least one muon, where the transverse momentum of the muon with respect to the closest jet axis or its impact parameter discriminate b events from the background. Measurements of the total and differential cross sections versus transverse momentum and rapidity for B+, B0, Bs mesons are also presented. Finally, a measurement of the angular correlations between beauty and anti-beauty hadrons is presented, probing for the first time the small angular separation region. The B hadrons are identified by the presence of secondary vertices from their decays and their kinematics reconstructed combining the decay vertex with the primary interaction vertex.The results are compared with predictions based on perturbative QCD calculations at leading and next-to-leading order.
        Orateur: Mauro Dinardo
        Transparents
      • 17:00
        Heavy Flavor Production in ATLAS 15m
        We present a measurement of the inclusive and dijet differential cross sections of heavy flavoured hadrons and b-jets produced in proton--proton collisions at s=7\,TeV, using data collected with the ATLAS detector. Jets are reconstructed using the anti-kt algorithm with jet radius parameter R=0.4\,. The presence of a displaced vertex from the decay of long-lived hadrons, or the presence of a muon with significant transverse momentum relative to the jet axis, is used to select a jet sample enriched in b-jets and the invariant mass of the charged particle tracks forming the vertex is fitted to extract the fraction of jets from b-quark production. The inclusive cross section is measured as a function of jet transverse momentum, in the range 20<\pt<260\,GeV, and of rapidity, in the range 0<|y|<2.1, where jets are fully contained in the tracking detectors of ATLAS. The dijet cross section is measured in the same rapidity range as a function of the dijet invariant mass, extending up to 670 GeV. The resulting cross sections are compared with next-to-leading-order QCD predictions.
        Orateur: Andreas Salzburger
        Slides
      • 17:15
        QCD effects and search for new physics in t−>bW 15m
        The most general new physics effective operators in the decay of an unpolarized top quark into a bottom quark and a W gauge boson are considered at next-to-leading order in QCD. We find that the dipole operator O_{LR} contribution to the transverse-plus W helicity fraction F_+ is significantly enhanced compared to the leading order result at non-vanishing bottom quark mass. Nonetheless, presently the most sensitive observable to direct O_{LR} contributions is the longitudinal W helicity fraction F_L. In particular, the most recent CDF measurement of F_L already provides the most stringent upper bound on O_{LR} contributions, even when compared with indirect bounds from the rare decay B -> X_s gamma.
        Orateur: Prof. Svjetlana Fajfer (Institute Jozef Stefan and Ljubljana University)
        Slides
      • 17:30
        Exclusive production of Higgs boson, $b \bar b$ and gluonic jets 15m
        We discuss the central exclusive production of Higgs boson and $q\bar{q}$ pairs in proton-proton (proton-antiproton) collisions at LHC and Tevatron. The amplitude for both processes is derived within the $k_t$-factorization approach and discussed in different kinematical asymptotia. In particular, we consider important high-$p_t$ and massless quark limits for $q \bar q$ production. Rapidity distributions, quark jet $p_t$ distributions, invariant $q\bar{q}$ mass distributions, angular azimuthal correlations between outgoing protons and between ougoing jets are presented. Exclusive $b \bar b$ production constitutes an irreducible background for exclusive Higgs production The $b{\bar b}$ background is analyzed in detail, in particular we study how to impose cuts to maximize signal-to-background ratio and show some solutions. We consider also central exclusive production of $gg$ dijets. The amplitude for the process is derived within the $k_t$-factorization approach (with both the standard QCD and the Lipatov's effective 3-gluon verticies) and is considered in various kinematical asymptotia, in particular, in the important limit of high-$p_t$ jets. Compared to earlier works we include emissions of gluons from different gluonic $t$-channel lines. Rapidity distributions, gluon jet $p_t$ distributions, invariant dijet mass distributions, angular azimuthal correlations between outgoing protons and jets are presented. We explore the competition of the standard diagram with both jets emitted from a single $t$-channel gluon and the one with the emission from both $t$-channel gluons. We find that the latter contribution is much smaller than that known from the literature. It becomes comparable only when the jet rapidity difference is large or the gluon transverse momenta are very small. It can, therefore, give contributions to the central diffractive production of mesons. We compare our results with the Tevatron data for exclusive dijets. \item R. Maciu{\l}a, R.S. Pasechnik and A. Szczurek, "Exclusive double-diffractive production of open charm in proton-proton and proton-antiproton collisions", Phys. Lett. {\bf B685} (2010) 165. \item R. Maciu{\l}a, R. Pasechnik and A. Szczurek, ``Exclusive $b \bar b$ pair production and irreducible background to the exclusive Higgs boson production'', Phys. Rev. {\bf D82} (2010) 114011. \item R. Maciu{\}a, R. Pasechnik and A. Szczurek, ``Central exclusive quark-antiquark dijet and Standard Model Higgs boson production in proton-(anti)proton collisions, arXiv:1011.5842, to be published in Phys. Rev.D
        Orateur: Prof. Antoni Szczurek (Rzeszow University and Institute of Nuclear Physics PAN)
        Transparents
      • 17:45
        Heavy Flavor production at HERA with ZEUS 15m
        The production of D*+, D0, D+, D+_s and lambda_c+ charm hadrons in ep scattering at HERA was measured with the ZEUS detector using the full HERA II data sample. The measurement has been performed in the photoproduction regime. The fractions of c quarks hadronising as a particular charm hadron, f(c-> D,lambda_c) were derived and are compared to the previous HERA results and to those obtained in e+e- annihilations. Inclusive photoproduction of D* mesons has also been measured with the ZEUS detector at HERA. The measurement was performed for photon-proton centre-of-mass energies in the range 130 < W < 285 GeV and photon virtuality Q2 < 1 GeV2. The D* mesons have been reconstructed from the decay channels D+ -> D0 pi_s+ with D0 -> K- pi+ or D0 -> K- pi+ pi+ pi- (+c.c.). Charm production has been measured with the ZEUS detector in deep inelastic ep scattering at HERA. The measurement is based on the full reconstruction of the decay chain D*->D0pis, D0->Kpi and exploits the full HERA II statistics. Differential cross sections have been measured and the charm contribution to the proton structure function, F2c, has been extracted. Charm production in deep inelastic scattering has also been measured. The hadronic decay channels D+ -> K0S pi+, Lambda_c+ -> p K0S and Lambda_c+ -> Lambda pi+, and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < pT(D+,Lambda_c+) < 10GeV, |eta(D+,Lambda_c+)| < 1.6, 1.5 < Q2 < 1000GeV2 and 0.02 < y < 0.7. Inclusive and differential cross sections for the production of D+ mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into Lambda_c+ baryons is extracted.
        Orateur: Olena Bachynska
        Slides
      • 18:00
        Heavy flavour production at HERA with H1 15m
        Measurements of cross sections for events with charm and beauty jets in deep inelastic scattering with the H1 detector at HERA are presented. The numbers of charm and beauty jets are determined using variables reconstructed using the H1 vertex detector with which the impact parameters of the tracks to the primary vertex and the position of secondary vertices are measured. The measurements are compared with QCD predictions and with previous measurements where heavy flavours are identified using muons. The cross section of b bar{b} photoproduction in ep collisions is also measured. Events containing b-quarks are identified through detection of two low momentum electrons in the final state. The differential b-quark production cross section is measured as a function of the transverse b-quark momentum and extends the previously experimentally accessible phase space towards the b-quark production threshold. The inclusive production of D*(2010) mesons in deep-inelastic ep scattering is measured in the kinematic region of photon virtuality 100 < Q2 < 1000 GeV2 and inelasticity 0.02 < y < 0.7. The charm contribution, F_2^{ccbar}, to the proton structure function F_2 is determined. Photoproduction of events containing a D* meson and two jets are investigated with the H1 detector using the HERA-II data sample. The D* mesons are reconstructed in the golden decay channel D* -> K pi pi_s. Differential cross sections are measured in different variables and compared to QCD calculations. Inclusive production of D* mesons in deep-inelastic scattering at HERA is studied in the range 5 < Q2 < 100 GeV2 of the photon virtuality and 0.02 < y < 0.7 of the inelasticity of the scattering process. The visible range for the D* meson is p_T(D*) > 1.25 GeV and |eta(D*)| < 1.8. Single and double differential cross sections are measured. The results are compared to QCD predictions.
        Orateur: Andreas Meyer
        Slides
      • 18:15
        Charm and beauty jet production at HERA with ZEUS 15m
        The production of charm and beauty quarks in deep inelastic scattering has been measured with the ZEUS detector using the full HERA II data set. The charm and beauty contents in events with a jet were determined using the decay length significance and invariant mass of inclusive secondary decay vertices. Differential cross sections as functions of Q2, Bjorken x, E_T^jet and eta^jet were measured and compared to theoretical predictions. The open charm and beauty contributions to the proton structure function F_2 were extracted. Beauty production in deep inelastic scattering with events in which a muon and a jet are observed in the final state has been measured using an integrated luminosity of 114 pb-1. The fraction of events with beauty quarks in the data was determined using the distribution of the transverse momentum of the muon relative to the jet. The cross section for beauty production was measured in the kinematic range of photon virtuality, Q2 > 2 GeV2, and inelasticity, 0.05 < y < 0.7, with the requirement of a muon and a jet. Total and differential cross sections are presented and compared to QCD predictions. The beauty contribution to the structure function F_2 was extracted and is compared to theoretical predictions. The production of charm and beauty quarks was measured in photoproduction at centre-of-mass energy of 320GeV using the properties of their secondary vertices, specifically by exploiting the lifetimes and masses of the ð- and ð- hadrons. This procedure is considerably more precise than previously used exclusive methods, where the reconstruction of selected decay channels puts a limit on the statistics. Kinematics of the outgoing quarks and their correlations were investigated.
        Orateur: M. Mykhailo Lisovyi (DESY)
        Slides
    • 16:30 18:30
      Top and Electroweak Physics Stendhal

      Stendhal

      Alpes Congrès - Alpexpo

      Président de session: Dr Andrea Ferroglia (New York City College of Technology)
      • 16:30
        Top quark physics at CDF 30m
        We present the recent results of top-quark physics using up to 8fb-1 of ppbar collisions analyzed by the CDF collaboration. The large number of top quark events analyzed, of the order of several thousands, allows stringent checks of the Standard Model predictions. Also, the top quark is widely believed to be a window to new physics. We will present the latest measurements of top quark intrinsic properties as well as direct searches for new physics in the top sector.
        Orateur: M. Karolos Potamianos (Purdue University)
        Slides
      • 17:00
        Measurement of the top quark mass and the top-antitop invariant mass in pp collisions at 7 TeV with the CMS detector 30m
        We present measurements of the top quark mass in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV using data collected by the CMS experiment during the year 2011. Measurements are presented in all possible final states originating from top-pair production, and the different reconstruction methods to extract the top quark mass are discussed. Particular emphasis will be given to the contribution of systematic uncertainties. The results of the various channels are combined and compared to the world average. The determination of the top-pair invariant mass is also presented, and the result interpreted in the light of possible new physics signatures in the production of top-quark pairs.
        Orateur: Martijn Mulders (CERN)
        Transparents
      • 17:30
        Measurement of the top pair production cross section and properties of top quark production and decay in proton-antiproton collisions at $\boldsymbol{\sqrt{s}}$=1.96 TeV using the D0 Detector 30m
        A number of results on the production and decay properties of top quark are presented. Results include a study of spin correlations in ttbar production, a search for favor changing neutral currents in top decays, a measurement of color-flow in ttbar events and a measurement of the W boson helicity.
        Orateur: Alexander Grohsjean (CEA Saclay Irfu/SPP)
        Transparents
      • 18:00
        Properties of the top quark decays in ATLAS 30m
        We present results on top quark decay properties using data collected in 7 TeV LHC proton-proton collisions with the ATLAS detector, including W boson polarisation in top quark decays and the search for FCNC in decays of top quarks.
        Orateur: Pamela Ferrari
        Transparents
    • 16:30 18:30
      Ultrarelativistic Heavy Ions Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      Président de session: Dr Jorge Casalderrey Solana (CERN)
      • 16:30
        Jet measurements by the CMS experiment in pp and PbPb collisions 30m
        The energy loss of fast partons traversing the strongly interacting matter produced in high-energy nuclear collisions is one of the most interesting observables to probe the nature of the produced medium. The multipurpose Compact Muon Solenoid (CMS) detector is well designed to measure these hard scattering processes with its high resolution calorimeters and high precision silicon tracker. Analyzing data from pp and PbPb collisions at a center-of-mass energy of 2.76 TeV parton energy loss is observed as a significant imbalance of dijet transverse momentum. To gain further understanding of the parton energy loss mechanism the redistribution of the quenched jet energy was studied using the transverse momentum balance of charged tracks projected onto the direction of the leading jet. In contrast to pp collisions, a large fraction the momentum balance for asymmetric jets is found to be carried by low momentum particles at large angular distance to the jet axis. Further the fragmentation functions for leading and subleading jets were reconstructed and are compared to model calculations and measurements in pp collisions. The results confirm and complement earlier CMS results based on calorimeter jets and yield a detailed picture of parton propagation in the hot QCD medium.
        Orateur: Frank Ma
        Slides
      • 17:00
        Probing nuclear parton densities and parton energy loss processes through photon + heavy-quark jet production in p-A and A-A collisions 15m
        We present a detailed phenomenological study of the associated production of a prompt photon and a heavy quark jet (charm or bottom) in proton-nucleus (p-A) and nucleus-nucleus (A-A) collisions. The dominant contribution to the cross-section comes from the gluon--heavy-quark (gQ) initiated subprocess, making this process very sensitive to the gluon and the heavy-quark nuclear parton densities. We show that the future p-A data to be collected at the LHC should allow one to disentangle the various nPDF sets currently available. In heavy-ion collisions, the photon transverse momentum can be used to gauge the initial energy of the massive parton which is expected to propagate through the dense QCD medium produced in those collisions. The two-particle final state provides a range of observables (jet asymmetry, photon-jet pair momentum, among others), through the use of which a better understanding of parton energy loss processes in the massive quark sector can be achieved, as shown by the present phenomenological analysis carried out in Pb-Pb collisions at the LHC.
        Orateur: Dr Tzvetalina Stavreva (LPSC)
        Transparents
      • 17:15
        Heavy flavour measurements in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$~TeV with the ALICE experiment 15m
        The ALICE experiment studies the properties of the QCD matter at the extreme energy densities of the ultra-relativistic heavy-ion collisions at the LHC. Produced on a very short time-scale in the initial hard-scattering processes, the heavy quarks (charm and beauty) experience the whole collision evolution: measuring the open heavy flavour spectra allows to investigate the mechanisms of energy-loss and hadronization in the hot and dense medium formed in the nucleus-nucleus collision. In particular, the ALICE capability to disentangle charm and beauty production is expected to help investigating the predicted quark-mass dependence of the in-medium energy-loss. The ALICE detector measures heavy-flavours in the semi-electroinc and semi-muonic decay channels at mid- and forward rapidity, respectively, and D mesons at mid-rapidity. The results in lead-lead collisions at $\sqrt{s_{NN}} = 2.76$~TeV and proton-proton collisions at $\sqrt{s} = 7$~TeV will be presented. The nuclear modification factor $R_{AA}$, defined as the ratio between the heavy-flavour production in nucleus-nucleus and proton-proton collisions rescaled to the number of binary collisions of nucleons in nuclei, will be discussed. The central to peripheral nuclear modification factor $R_{CP}$, obtained from the comparison of the measurements in heavy-ion collisions with a small and large impact parameter, respectively, will be presented as well.
        Orateur: Dr Diego Stocco (Subatech)
        Transparents
      • 17:30
        Quarkonium Production at STAR 15m
        The production of quarkonium has been studied to provide information about the hypothesized Quark Gluon Plasma (QGP) that is expected to be created in relativistic heavy ion collisions at RHIC. Lattice QCD predicts a suppression of quarkonium production in the presence of a hot and dense medium relative to proton-proton collisions, with the suppression pattern of the various quarkonium states providing insight into the thermodynamic properties of the QGP. The suppression is expected due to the Debye screening of the potential between heavy quarks in a dense medium. However there are other effects due to the presence of a QGP which may contribute to the modification of heavy quark production, such as statistical coalescence of heavy quark-antiquark pairs, or co-mover absorption. There are also ordinary Cold Nuclear Matter (CNM) effects, such as the modification of nuclear PDFs (shadowing), and final state nuclear absorption, which need to be taken into account in order to fully quantify an anomalous suppression. This can be achieved by studying the production of various quarkonium states in p+p, d+A and A+A collisions. Furthermore, p+p collisions can offer insight to the quarkonium production mechanism and feed down effects from higher states.\\ In this talk we will report the results on heavy quarkonium production in p+p, d+Au, and Au+Au collisions at midrapidity via the dielectron decay channel at $\sqrt{s_{NN}} = 200$ GeV from STAR. Results from J/$\psi$ production in p+p collisions will be presented to provide a baseline for production and understand the quarkonium production mechanism. The nuclear modification factor for J/$\psi$ will also be reported, along with results from Upsilon production in p+p, d+Au, and Au+Au collisions, to investigate the suppression of quarkonium at STAR.
        Orateur: M. Christopher Powell (Lawrence Berkeley National Laboratory)
        Slides
      • 17:45
        J/psi production measurements in pp and PbPb collisions in the ALICE experiment at the LHC 15m
        ALICE is the experiment dedicated to heavy-ion studies at the LHC and, in particular, it aims at a comprehensive study of the hot and dense colour-deconfined state of matter called Quark-Gluon Plasma. Quarkonia resonances are considered as powerful probes of the deconfined phase since the heavy quark pairs pairs are produced in the early stages of the collision and their bound states are very sensitive to the coloured medium which they traverse. The reference for heavy-ion studies is given by pp collision measurements, which are also interesting per se for addressing unresolved issues in the description of quarkonia hadroproduction. In particular the study of the pT distribution and of the polarization of quarkonia allow interesting tests of the currently available theoretical models. The ALICE experiment was designed to perform the detection of J/psi resonances, down to pT=0, both in the di-electron (at mid-rapidity: |y| < 0.9) and di-muon (at forward-rapidity: 2.5 < y < 4) decay channels and it has collected J/psi samples with proton beams colliding at sqrt(s) = 7 and 2.76 TeV and with lead beams colliding at 2.76 TeV per nucleon pair. The results on the differential (pT and y) cross-sections for inclusive J/psi production in pp collisions at the two energies will be discussed as well as the current status of the J/psi polarization analysis. For PbPb collisions preliminary results on the nuclear modification factor (R_AA and R_CP) will be shown and compared with results from previous experiments.
        Orateur: M. Livio Bianchi (INFN Torino - Universita' di Torino)
        Slides
      • 18:00
        Quarkonia measurements by the CMS experiment in PbPb collisions 15m
        CMS is fully equipped to measure hard probes in the di-muon decay channel in the high multiplicity environment of nucleus-nucleus collisions. Such probes are especially relevant for studying the quark gluon plasma since they are produced at early times and propagate through the medium, mapping its evolution. Quarkonia and bottomonia are sensitive to the evolution of the medium. In particular, the $J\psi$ production in heavy ion collisions has been studied at different energies and with different collision systems without yet giving a global picture that is fully understood. Measuring the charmonium production at the LHC energies in PbPb collisions will help constraining predictions, in particular those expecting high recombination of prompt J$/\jpsi$s or suppression in hot medium. We will review CMS J/\psi measurements in pp collisions at $\sqrt{s_{NN}}=7$~TeV, which allow precision studies of quarkonia production and serve as a reference for the observation of hot nuclear effects. CMS is able to distinguish non-prompt J$/\psi$ from prompt J/$\psi$ in PbPb collisions, and will present the prompt J/$\psi$ production cross-section in PbPb inclusively and as a function of transverse momentum, rapidity and number of nucleons participating in the collision. Finally, we compare the B fraction measured in PbPb collisions with that measured in pp at various energies. The LHC centre-of-mass energy allows copious $\Upsilon$ production in PbPb collisions. Detailed measurements of bottomonium will help characterize the dense matter produced in heavy-ion collisions beyond what was accessible at RHIC (mostly) with charmonia. The full spectroscopy of quarkonium states has been suggested as a possible thermometer for the QGP. With its excellent dimuon mass resolution, CMS has measured the three $\Upsilon$ states in pp collisions. With the 2010 PbPb data sample, CMS has observed the $\Upsilon$(1S) as well as excited states. The $\Upsilon(1S)$ cross-section is presented as a function of transverse momentum, rapidity and centrality, and excited state. Suppression of the excited state in PbPb will be discussed.
        Orateur: Mme Catherine Silvestre (LPSC, UIC, LANL (now LPSC, work done with UIC and LANL))
      • 18:15
        Production of lepton, quark and meson pairs in peripheral ulrarelativistic heavy ion collisions 15m
        We discuss exclusive production of lepton-antilepton, quark-antiquark, $\pi \pi$ and $\rho^0 \rho^0$ and $D \bar D$ meson pairs in ultraperipheral, ultrarelativistic heavy-ion collisions i.e. processes initiated by photon-photon fusion which could be studied at RHIC and LHC. The cross sections for exclusive muon pair production in nucleus - nucleus collisions was calculated and several differential distributions are shown. Realistic (Fourier transform of charge density) charge form factors of nuclei are used and the corresponding results are compared with the cross sections calculated with monopole charged form factor of a nucleus often used in the literature. Absorption effects are discussed and quantified. The cross sections obtained with realistic form factors are significantly smaller than those obtained with the monopole form factor. The effect is bigger for large muon rapidities and/or large muon transverse momenta. We show predictions for STAR and PHENIX collaborations at RHIC as well as ALICE and CMS collaborations at LHC. The cross section for exclusive heavy quark and heavy antiquark pair ($Q \bar Q$) production in peripheral ultrarelativistic heavy ion collisions was calculated for the LHC energy $\sqrt{s_{NN}}$ = 5.5 TeV. We present results in the impact parameter equivalent photon approximation (EPA) and compare some of them with results obtained by exact calculations of the Feynman diagrams in the momentum space. We include both $Q \bar Q$, $Q \bar Q g$ and $Q \bar Q q \bar q$ final states as well as photon single-resolved components. Realistic charge densities in nuclei were taken in the calculation. The different components give contributions of the same order of magnitude to the nuclear cross section. We present for the first time cross section for exclusive production of $\pi^+ \pi^-$ and $\pi^0 \pi^0$ pairs. The elementary process $\gamma \gamma \to \pi \pi$ is discussed in detail. We concentrate on high-$p_t$ processes. We consider pQCD processes ala Brodsky-Lepage or alternatively hand-bag mechanism. The nuclear cross section is calculated within b-space EPA for RHIC and LHC. Similar analysis is performed for $\rho^0 \rho^0$ production, where the elementary cross section is less known. Our analysis includes a low-energy phenomenon (close-to-threshold enhancement of the cross section). The cross section for the low-energy phenomenon is parametrized and the high-energy cross section is calculated in a simple Regge model. Predictions for heavy ion collisions are presented. The cross sections for exclusive $D^+ D^-$ and $D^0 \bar {D^0}$ meson pair production in peripheral nucleus - nucleus collisions are calculated and several differential distributions are presented. The calculation of the elementary $\gamma \gamma \to D \bar D$ cross section is done within the heavy-quark approximation and in the Brodsky-Lapage formalism with distribution amplitudes describing recent CLEO data on leptonic $D^+$ decay. The cross sections of a few nb are predicted for RHIC and of a few hundreds of nb for LHC with details depending on the approximation made in calculating elementary $\gamma \gamma \to D \bar D$ cross sections. The speaker will present these different results to domonstrate how reach is the option of ultrarelativistic ultraperipheral collisions at RHIC and LHC. Literature: \item M. K{\l}usek, W. Sch\"afer and A. Szczurek, "Exlusive production of $\rho^0 \rho^0$ pairs in $\gamma \gamma$ collisions at RHIC", Phys. Lett. {\bf B674} (2009) 92. \item K{\l}usek-Gawenda and A. Szczurek, ``Exclusive muon-pair production in utrarelativistic heavy-ion collisions - realistic nucleus charge form factor and differential distributions'', Phys. Rev. {\bf C82} (2010) 014904. \item M. K{\l}usek-Gawenda, A. Szczurek, M. Machado and V. Serbo, ``Double -- photon exclusive processes with heavy quark -- heavy antiquark pairs in high-energy Pb-Pb collisions at LHC'', Phys. Rev. {\bf C83} (2011) 024903. \item M. {\L}uszczak and A. Szczurek, ``Exclusive $D \bar D$ meson pair production\\ in peripheral ultrarelativistic heavy ion collisions'', arXiv:1103.4268, in print in Phys. Lett.B \item M. K{\l}usek-Gawenda and A, Szczurek, arXiv:1104.0571, in print in Phys. Lett.B
        Orateur: Prof. Antoni Szczurek (Rzeszow University and Institute of Nuclear Physics PAN)
        Transparents
    • 20:00 22:30
      City Hall Reception 2h 30m Museum of Grenoble (Grenoble Downtown)

      Museum of Grenoble

      Grenoble Downtown

    • 09:00 10:30
      Cosmology and Gravity Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 09:00
        Dark Energy and Modified Gravity 35m
        Despite more than 10 years of intense experimental and theoretical work, no plausible explanation to the acceleration of the universe is available yet. Dark energy and modified gravity are two likely candidates. I will review their current status and state the problems that they both face. In particular, it turns out that at low energy both approaches reduce to scalar field models essentially. In both cases, the scalar degree of freedom may induce deviations from Newton's law in the solar system and the laboratory, a phenomenon which needs to be screened off. I will present the different screening mechanisms and how the study of large scale structures of the Universe may help to distinguish dark energy/modified gravity models. Eventually I will concentrate on possible laboratory tests of these models and even some consequences for collider physics.
        Orateur: Dr Philippe Brax (CEA-Saclay)
        Slides
      • 09:45
        Supernova Legacy Survey 3-years data sample 35m
        We present the recent results from the analysis of the Supernova Legacy Survey 3-years data sample. For the dark energy equation of state, assuming a flat universe, we measure a w parameter consistent with a cosmological constant with a precision of 0.2. We have paid particular attention to the systematic uncertainties. We combine the SNe data with baryon acoustic oscillation measurements from the Sloan Digital Sky Survey (SDSS) and measurements of the cosmic microwave background power spectrum from the WMAP-7 year data, to obtain, under the flat universe hypothesis, a measurement of the dark energy equation of state w = -1.068 with a precision of 0.08.
        Orateur: Dr Delphine Hardin (LPNHE)
        Slides
    • 09:00 10:30
      Detector R & D and Data Handling Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      • 09:00
        Alignment and Calibration of the CMS Detector 15m
        Fast and efficient methods for the calibration and the alignment of the detector are a key asset to exploit the physics potential of the CMS detector. The CMS experiment has set up a powerful framework for alignment and calibration, which is based on dedicated skims providing a highly compact dedicated input for the various workflows computing the constants. This includes a prompt calibration concept, which allows for a fast turnaround of the calibration process which is instrumental to ensure timely preparation of results for conferences and publications. The presentation reviews the design of the system, reports on the experience gained during its operation including results from selected workflows.
        Orateur: Gianluca Cerminara (CERN)
        Transparents
      • 09:15
        Jet Energy Calibration and Transverse Momentum Resolution in CMS 15m
        We present results on the jet energy calibration and jet transverse momentum resolution at CMS. In-situ measurements are performed using couple of 100/pb of proton-proton collisions at 7 TeV center of mass energy. The transverse momentum balancing in dijet and photon/Z+jet events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different approaches to reconstruct jets in the CMS: calorimeter-based jet reconstruction; the Jet-Plus-Track algorithm, which improves the measurement of calorimeter jets by exploiting the associated tracks; the Particle Flow method, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant sub-detectors.
        Orateurs: Ia Iashvili (SUNY Buffalo) , Dr Manfred Krammer (HEPHY, Vienna)
        Transparents
      • 09:30
        Precision Calibration of the Luminosity Measurement in ATLAS 15m
        A precision luminosity measurement is of critical importance for the ATLAS physics program, both for searches for new physics as well as for precision measurements of Standard Model cross-sections. The calibration of the luminosity is based on three so-called van der Meer scans that were performed in 2010. The calibration determines the convolved beam sizes in the vertical and horizontal directions, and together with the precise knowledge of the beam current a luminosity calibration can be determined. Based on this analysis ATLAS has determined the luminosity with a total uncertainty of only 3.4% for the 2010 data at sqrt(s)=7 TeV.
        Orateur: M. Vincent Hedberg (Lund University)
        Transparents
      • 09:45
        Tracker and Calorimeter Performance for the Identification for Hadronic Tau Lepton Decays in ATLAS 15m
        Tau leptons will play an important role in the physics program at the LHC. They will be used not only in searches for new phenomena like the Higgs boson or Supersymmetry and electroweak measurements but also in detector related studies like the determination of the missing transverse energy scale. Identifying hadronically decaying tau leptons requires good understanding of the detector performance, combining the calorimeter and tracking detectors. We present the current status of the tau reconstruction and identification at the LHC with the ATLAS detector. The identification efficiencies are measured by W->taunu and Z->tautau events, and compared with the prediction of the Monte Carlo simulation. The performance of the fake tau rejection is also estimated in jet-enriched data samples from dijets, multi-jets, gamma+jets and Z+jets events.
        Orateur: Stanley Lai
        Transparents
      • 10:00
        Performance of the LHCb Detector during 2010-2011 data taking 15m
        The status and performance of the LHCb detector during the physics LHC physics run is described. The detector has a number of notable features including: 13 micron resolution in the transverse plane on 25 track primary vertices, pion and kaon separation from 1 to 100 GeV, and 1 MHz full readout of all sub-systems. The detector is being operating above its design luminosity. The detector is comprised of a silicon vertex detector (vertex locator - VELO), silicon and straw-tube tracking systems (inner and outer trackers), ring imaging cherekov particle identification systems (RICH), electromagnetic and hadronic calorimetry, and muons systems. Hardware and software based trigger levels are utilised to efficiently select leptonically and hadronically decay beauty and charm hadrons.  The alignment, tracking and particle identification performance will be discussed.
        Orateur: Dr Martin van Beuzekom (Nikhef)
        Transparents
      • 10:15
        MET Performance with CMS 15m
        In this talk we report comprehensive results of studies of missing transverse energy (MET) measured by the CMS detector in pp collisions at a centre-of-mass energy of 7 TeV. Three MET reconstruction algorithms are deployed for various physics analyses. The scale and resolution for MET are validated using vector boson and dijet events, and severe mismeasurements due to the detector are studied. We also parametrize the effects of multiple pp interactions within the same bunch crossings on the scale and resolution. A tool, called MET significance, based on particle resolutions in each event is also presented.
        Orateur: M. FLORENT LACROIX (UIC/FERMILAB)
        Transparents
    • 09:00 10:30
      Flavour Physics and Fundamental Symmetries Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 09:00
        Fourth Generation: From B Factories, to Colliders and to the Cosmos 15m
        Adding another generation to the Standard Model is just about the simplest extension available to us; yet it has profound consequences.While there are many motivations for it, it appears now that the data from B-factories is very difficult to reconcile with the CKM-paradigm with just three families. Addition of a new family is just about the simplest way to address these difficulties. That modification then leads very interesting implication for improved experiments at high intensity frontiers such as LHCb and Super-B factories. It also has important repercussions for search strategies at the LHC. The scenario not only has profound consequences for baryogenesis but also in providing a viable dark matter candidate.
        Orateur: amarjit soni (BNL)
        Slides
      • 09:15
        SUSY Flavour at LHC7 15m
        The current run of the LHC experiment shall be able to probe gluino and squark masses up to values of about 1 TeV. Assuming that hints for SUSY are found by the end of this run, we explore the flavour constraints on the parameter space of the CMSSM, with and without massive neutrinos. In particular, we focus on decays that might have been measured by the time the run is concluded, such as $B_s\to\mu\mu$ and $\mu\to e\gamma$.
        Orateur: Dr Joel Jones-Perez (INFN - LNF)
        Slides
      • 09:30
        Recent BABAR Charm Physics Results 15m
        We report recent BABAR charm physics results, including CP violation studies in D+->Ks0pi+ and D+ ->Ks0 h+h+h-, a study of the Dalitz plot of Ds+->K+K-pi+, measurements of the mass and width of the Ds1(2536)+, measurements of charm semileptonic and leptonic branching fractions, and searches for non-hadronic rare D decays.
        Orateur: M. Maurizio Martinelli
        Slides
      • 09:45
        D(s)+ decays and CPV/mixing at Belle 15m
        We report a measurement of $D^0$ - $\bar D^0$ mixing in $D^{0} \to K_S^0 \pi^{+} \pi^{-}$ decays using a time-dependent Dalitz plot analysis. We will also present an updated measurement of the mixing parameter $y_{CP}$ in decays $D^0 \to K^+K^-$ and $D^0 \to \pi^+\pi^-$. We will present a measurement to search for $CP$ violation in charged $D$ meson decays by measuring the $CP$ violating asymmetry difference between Cabibbo-suppressed decays $D^+ \to K^+K^- \pi^+$ and Cabibbo- favored decays $D_s^+ \to K^+K^- \pi^+$ in a mass region of the $\phi$ resonance. We have searched for CP violation in the decays $D^0\rightarrow K^0_S P^ 0$ where $P^0$ denotes a neutral pseudo-scalar meson which is either a $\pi ^0$, $\eta$, or $\eta'$. No evidence of significant CP violation is observed. We report the most precise CP asymmetry measurement in the decay $D^0\rightarrow K^0_S\pi^0$ to date: $A_{CP}^{D^0\rightarrow K^0_S\pi^0} =(-0.28\pm0.19\pm0.10)%$. We also report the first measurements of CP asymmetries in the decays $D^0\rightarrow K^0_S\eta$ and $D^0\rightarrow K^0_S\eta'$: $A_{CP}^{D^0\rightarrow K^0_S\eta}=(+0.54\pm0.51\pm0.16)%$ and $A_{CP}^{D^0\rightarrow K^0_S\eta'}=(+0.98\pm0.67\pm0.14)%$, respectively. We report the first observations of the decay $D^+ \to K^+ \eta^{(')}$ and the search for the CP violation in the decay $D^+ \to \pi^+ \eta^{(') }$. The branching ratios with respect to their normalization modes and CP measurements will be presented. We report preliminary results on the time-integrated asymmetry of the decays $D^0$ and $\bar{D^0}$ to $\pi^+ \pi^- \pi^0$. Results of the Dalitz plot analysis of $A_{CP}$ for two approaches -- model dependent and model independent -- are presented. The results are obtained from a large data sample collected on the $\Upsilon(4S)$ and $\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^+ e^-$ collider.
        Orateur: Dr Marko Staric (Jozef Stefan Institute)
        Slides
      • 10:00
        Mixing and CP-violation studies in charm decays at LHCb 15m
        LHCb has collected a large sample of open charm events in the 2010 run. Indirect CP violation in charm is an excellent probe for new physics due to the smallness of the standard model predictions. Preliminary measurements of mixing parameters and searches for CP violation in the time-dependence of two-body charm decays are presented. The prospects of improving the sensitivity of these measurements in the 2011-12 run are discussed. Preliminary results of searches for time-integrated CP violation in two, three and four-body charm decays at LHCb are presented, using 37 pb-1 of data collected in 2010. We construct observables that are sensitive to direct CP violation, which is predicted to be small in the Standard Model, but insensitive to production and detector asymmetries. These searches are complementary to the time-dependent searches presented elsewhere. We conclude by discussing prospects for the 2011-12 run.
        Orateur: M. Matthew Charles
        Transparents
      • 10:15
        Production of the excited charm mesons D1_0 and D2*_0 with ZEUS at HERA 15m
        The production of the excited charm mesons D1(2420)0 and D*2(2460) in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 373 pb-1. The masses, widths and helicity parameters of these resonances were determined and compared with previous measurements, with theoretical expectations and with published ZEUS results of an independent sample with an integrated luminosity of 126 pb-1. The measured D01 width is found to be above the world average value in both cases. The measured D01 helicity parameter allows for some mixing of S- and D-waves in its decay to D* pi; however the result is also consistent with the prediction for a pure D-wave decay.
        Orateur: Yuriy Onishchuk
        Slides
    • 09:00 10:30
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 09:00
        W/Z plus jets/multi-jets 30m
        W/Z plus jets/multi-jets
        Orateur: Christoph Englert
        Transparents
      • 09:30
        Combined upper limit on Standard Model Higgs boson production in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV at CDF} 15m
        We present the combination of the searches for the Standard Model Higgs boson at a center-of-mass energy of $\sqrt{s}=$1.96~TeV, using up to 8.9~fb$^{-1}$ of data collected with the CDF detector at the Fermilab Tevatron collider. The major contributing processes include associated production ($WH\to \ell\nu bb$, $ZH\to\nu\nu bb$, $ZH\to \ell\ell bb$, and $WH\to WWW^{(*)}$) and gluon fusion ($gg\to H\to WW^{(*)}$). The significant improvements across the full mass range resulting from the larger data sets, improved analyses and inclusion of additional channels are discussed. The combination of all channels results in significantly improved sensitivity across the 100-200 GeV mass range, and in particular around 160 GeV.
        Orateur: Adrian Buzatu
        Slides
      • 09:45
        Combined upper limit on Standard Model Higgs boson production in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV at D0 15m
        We present the combination of the searches for the Standard Model Higgs boson at a center-of-mass energy of $\sqrt{s}=$1.96~TeV, using up to 8.5~fb$^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron collider. The major contributing processes include associated production ($WH\to \ell\nu bb$, $ZH\to\nu\nu bb$, $ZH\to \ell\ell bb$, and $WH\to WWW^{(*)}$) and gluon fusion ($gg\to H\to WW^{(*)}$). The significant improvements across the full mass range resulting from the larger data sets, improved analyses and inclusion of additional channels are discussed. The combination of all channels results in significantly improved sensitivity across the 100-200 GeV mass range, and in particular around 160 GeV.
        Orateur: sebastien greder (IPHC)
        Transparents
      • 10:00
        Searches for Supersymmetric Higgs bosons at Tevatron 15m
        We present searches for Higgs bosons in final states with $b$-quarks and/or taus at a center-of-mass energy of $\sqrt{s}=$1.96~TeV using up to 8.5~fb$^{-1}$ of data collected with the D0 detector. In Supersymmetric models the Higgs boson production cross section can be significantly enhanced compared to the Standard Model, and in such models the Higgs boson has a significant branching fractions to $\tau$ leptons at all masses and the gluon fusion production process can be exploited directly. In addition, the cross-section for production of neutral Higgs bosons in association with bottom quarks is greatly enhanced compared to the Standard Model. Therefore we also search for an excess of events above the multijet background in events with 3 and 4 $b$-jets exploiting the dominant decay channel of the Higgs boson to $b$ quarks, and also exploit the hybrid channel with $b$-quarks and $tau$ leptons. We combine the result of these 3 searche channels in the context of different scenarios within the Minimal Supersymmetric Standard Model.
        Orateur: Dr Fabrice Couderc (CEA/DAPNIA/SPP)
        Transparents
      • 10:15
        Search for H++->l+l+ and H+ -> tau nu in CMS 15m
        We present results from a search for an exotic Higgs Boson in the channel H++ --> l+l+ with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at sqrt s = 7 TeV. We also present results from a search for a charged Higgs Boson in ttbar decays in the channel H+ -> Tau nu with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at sqrt s = 7 TeV
        Orateur: Aruna Kumar NAYAK (LIP, Lisbon, Portugal)
        Transparents
    • 09:00 10:30
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 09:00
        COMPASS results on gluon polarisation 15m
        One of the missing keys in the present understanding of the spin structure of the nucleon is the contribution from the gluons: the so-called gluon polarisation. This quantity can be determined in DIS through the Photon-Gluon Fusion (PGF) process, in which two analysis methods may be used: (i) identifying open charm events or (ii) selecting events with high-p_T hadrons. The data used in the present work were collected by the COMPASS Experiment, where a naturally polarised muon beam of 160 GeV, impinging on a polarised nucleon fixed target, is used. Preliminary results for the gluon polarisation from high-p_T and open charm analyses are presented. The gluon polarisation result for high-p_T hadrons is divided, for the first time, into 3 independent x_g bins at LO. The result from open charm analysis is obtained at LO and NLO. In both analyses a new weighted method based on a neural network approach is used.
        Orateur: Dr Luis Silva (LIP Lisbon)
        Transparents
      • 09:15
        Open charm hadron production and spectroscopy at LHCb 15m
        Measurements for open charm hadron production and spectroscopy at LHCb, and future prospects are presented. The LHCb detector is designed for the observation of heavy flavour decays with a fully instrumented forward coverage that is unique among the LHC experiments. These features, with the prolific charm production in sqrt(s)=7 TeV proton-proton collisions, make LHCb ideally suited to perform precise measurements of charm production and spectroscopy that test QCD in this new energy regime.
        Orateur: Marco Pappagallo
        Slides
      • 09:30
        Hadron physics at COMPASS 15m
        The COMPASS experiment at CERN SPS is dedicated to the study of hadron structure and spectroscopy. One goal of the physics programme using hadron beams is the search for new states, in particular the search for J^{PC} spin-exotic states and glueballs. Apart from a short pilot run in 2004 (190 GeV/c negative pion beam, lead target), we started our hadron spectroscopy programme in 2008 by collecting unprecedented statistics with a negative hadron beam (190 GeV/c) on a liquid hydrogen target. A similar amount of data with positive hadron beam (190 GeV/c) has been taken in 2009, as well as some data (negative beam) on nuclear targets. Our spectrometer features good coverage by electromagnetic calorimetry, crucial for the detection of final states involving $\pi^0$ or $\eta. For scattering of negatively charged pions off nuclear targets, photon exchange dominates at very low momentum transfer, giving access to $\pi^-\gamma$ induced reactions (Primakoff). By detection of exclusive $\pi^-\gamma$ final states, COMPASS further aims at the precise measurement of the pion polarisability. Studying also the exclusive $\pi^-\pi^0$ final state, allows a precise determination of the chiral anomaly. We will present an selective overview of the status of various ongoing analyses and first results on the 2008/09 data.
        Orateur: Dr Frank Nerling (University of Freiburg)
        Slides
      • 09:45
        Determination of the light quark masses from eta --> 3 pi 15m
        Recently, an important effort has been devoted at KLOE, MAMI and COSY to precisely measure the eta --> 3 pi decays. These new measurements require to revisit the theoretical analyses of these decays. In this talk, we will present a new analysis of the eta --> 3 pi decay amplitude relying on dispersive methods. We will show how the study of this decay allows to extract a fundamental parameter of the Standard Model, namely the quark mass ratio (m_d^2-m_u^2)/(m_s^2-\hat{m}^2) with a very good precision. We will then discuss the possibility to extract the individual light quark masses.
        Orateur: Emilie Passemar (IFIC-University of Valencia)
        Transparents
      • 10:00
        Pion elastic and pi-gamma form factors at large momentum transfers 15m
        We study the pion elastic and the pi-gamma transition form factors at large values of the momentum transfers making use of the existing experimental data and two theoretical approaches: (i) the local-duality QCD sum rules and (ii) quantum-mechanical potential models with an interaction consisting of Coulomb and confining parts in which case the ground-state form factors satisfy factorization theorems similar to those in QCD. For the pion elastic form factor, we show that the existing data at Q²=1-6 GeV² lead to important consequences for the behaviour of the form factor at larger momentum transfers, up to asymptotically large values. For the pi-gamma from factor, we discuss possible dynamical mechanisms which could explain mysterious BaBar data for this form factor at Q²=10-30 GeV².
        Orateur: Dr Dmitri Melikhov (HEPHY, Vienna, Austria & SINP, Moscow, Russia)
        Transparents
      • 10:15
        Hadron Physics at KLOE and KLOE-2 15m
        The KLOE experiment has collected 2.5 fb-1 at the peak of the phi resonance at the e+e- collider DAPHNE in Frascati. The whole data set includes 100 million eta's produced through the radiative decay phi --> eta gamma and tagged by means of the monochromatic recoil photon. Measurements of eta decay channels, such as pi+ pi- gamma, are in progress. We have also measured the branching ratio of the eta --> e+ e- e+ e- decay channel, never observed before, with a sample of about 360 events. Pseudoscalar production at the phi-factory associated to internal conversion of the photon into a lepton pair allows the measurement of the form factor F(q1^2=M(phi)^2,q2^2>0) of pseudoscalar mesons in the kinematical region of interest for the VMD model. The only existing data on phi --> eta e+ e- are based on 213 events. At KLOE, a preliminary study of this decay has been performed on 739 pb-1 using the eta-->pi+pi-pi0 final state. Simple analysis cuts provide about 7000 signal events with very small residual background contamination. From a sample of 240 pb-1 taken off the phi resonance, a preliminary analysis of the e+ e- --> e+ e- eta process, without tagging e+e- in the final state is presented. Using two different decay channels, eta --> pi+ pi- pi0 and eta --> pi0 pi0 pi0, the cross section of the process e+ e- --> e+ e- eta is extracted. The same data set has been used to search for the f0(600) that can be produced in gamma-gamma interactions and observed in the reaction e+ e- --> e+ e- pi0 pi0. The preliminary pi0pi0 mass spectrum show an excess of events with respect to the expected background in the f0(600) mass region. A new beam crossing scheme allowing for a reduced beam size and increased luminosity is operating at DAPHNE. The KLOE-2 detector is successfully rolled in this new interaction region and is ready to acquire collision data. At the moment, the detector is being upgraded with small angle tagging devices, to detect both high and low e+e- energy in e+ e- --> e+ e- X events. The inner tracker and small angle calorimeters are scheduled to be installed in a subsequent step, providing wider acceptance for both charged particles and photons. The main goal of KLOE-2 is to collect an integrated luminosity of about 20 fb^-1 in 2-3 years in order to refine and extend the KLOE physics programme.
        Orateurs: Dr Federico Nguyen (INFN Roma TRE) , Paolo Gauzzi (Universita' degli Studi "La Sapienza" and Sezione INFN "Roma")
        Transparents
    • 09:00 10:30
      Top and Electroweak Physics Stendhal

      Stendhal

      Alpes Congrès - Alpexpo

      Président de session: Dr Jan Stark (Stark)
      • 09:00
        Production of electroweak gauge bosons at hadron colliders 30m
        Mini-review.
        Orateur: Dr Tobias Kasprzik (KIT)
        Slides
      • 09:30
        Measurements of Drell-Yan differential cross sections at the LHC and W Charg\ e Asymmetry in pp collisions at 7 TeV with the CMS detector 30m
        Measurements of inclusive W, Z and Drell Yan production cross sections and the W lepton charge asymmetry in pp collisions at 7 TeV center-of-mass energy, based on data recorded by the CMS detector at thE LHC in 2010 and 2011 are presented. The measurements are performed in the electron and muon channels. The charge asymmetry measurements cover the central region up to 2.4 in lepton pseudo rapidity. These results can be used to constrain the parton densities for valence quarks and sea anti quarks
        Orateur: Dimitri Bourilkov (University of Florida)
        Transparents
      • 10:00
        Electroweak boson production in the forward region with LHCb 30m
        We report on measurements of W and Z boson production, using muon final state topologies, with the LHCb experiment and using data taken at centre of mass energy of 7 TeV. Measurements of the inclusive W and Z production cross-sections, Z (W) differential cross-sections as a function of boson rapidity (muon pseudorapidity), their ratios, and the W charge asymmetry are presented and compared to theoretical predictions. We discuss the potential sensitivity such measurements display to the underlying parton density functions.
        Orateur: Tara Shears
        Slides
    • 10:30 11:00
      Coffee 30m Lobby

      Lobby

      Alpes Congrès - Alpexpo

    • 11:00 13:00
      Cosmology and Gravity Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 11:00
        The Lyman-alpha forest in three dimensions with BOSS 35m
        The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a five-year spectroscopic survey of 10,000 deg^2, achieved first light in late 2009. One of the key goals of BOSS is to measure the signature of baryon acoustic oscillations in the distribution of Ly-alpha absorption from the spectra of a sample of ~150,000 z>2.2 quasars. Along with measuring the angular diameter distance at z\approx2.5, BOSS will provide the first direct measurement of the expansion rate of the Universe at z > 2. During the first year of the BOSS survey, quasar target selection methods were developed and tested to meet the requirement of delivering at least 15 quasars deg^-2 in this redshift range, out of 40 targets deg^-2. Using a sample of approximately 14,000 z>2.2 quasars observed in this first year of BOSS, we measure the three-dimensional correlation function of absorption in the Lyman-alpha forest. A quadrupole distortion of the redshift-space correlation function by peculiar velocities, the signature of the gravitational instability origin of structure in the Lyman-alpha forest, is detected at high significance. These results set the stage for cosmological parameter determinations from three-dimensional structure in the Lyman-alpha forest, including anticipated constraints on dark energy from baryon acoustic oscillations.
        Orateur: Dr Christophe Yeche (IRFU-SPP / CEA-Saclay)
        Transparents
      • 11:45
        The WiggleZ Galaxy Survey shows that dark energy is real 35m
        The WiggleZ Dark Energy Survey on the Anglo-Australian Telescope has measured redshifts for 220,000 emission line galaxies. The galaxies sample a volume of 1 cubic Gpc and a redshift range of 0.2<z<1. This is the first survey to measure the cosmology of the universe over such a wide range of epochs. Our analysis provides strong evidence that dark energy is real. In our first major results we made two successful tests of the standard (“LCDM”) cosmological model dominated by a cosmological constant (L) and cold dark matter (CDM). First, we measured the effect of dark energy on the gravitational growth rate of cosmic structure. The measured growth rate is entirely consistent with the LCDM model over the whole redshift range measured. Second, we detected the imprint of baryon acoustic oscillations in the clustering of the WiggleZ galaxies, allowing us to measure the cosmological distance-redshift relation at z=0.6. The results confirm the LCDM model, as well as providing evidence for accelerating expansion of the universe that is independent of earlier supernova measurements. In a very different analysis of the WiggleZ data we used a novel method to make a direct, geometric measurement of the expansion rate of the Universe as a function of time. The increase in the expansion rate over the last 7 billion years shows that the universe is accelerating, independent of any cosmological model.
        Orateur: Prof. Michael Drinkwater (University of Queensland)
        Slides
      • 12:30
        The GRANIT project: status and perspectives 15m
        The GRANIT project is the follow-up of the pionnering experiments that first observed the quantum states of neutrons trapped in the earth’s gravitational field at the Institute Laue Langevin (ILL) [1]. Due to the weakness of the gravitational force, these quantum states exhibit most unusual properties: peV energies and spatial extensions of order 10 m. Whereas the first series of observations aimed at measuring the properties of the wave functions, the GRANIT experiment will induce resonant transitions between various states and measure their energy differences, thus improving dramatically the sensitivity. In this talk, I will present the status of the experiment presently under commissioning at the ILL. I will then discuss the potential of GRANIT to searches for new physics and in particular to a modified Newton law in the micrometer range. [1]. V.V. Nesvizhevsky et al, Nature 415 (2002); Phys. Rev. D 67 (2003) 102002.
        Orateur: Dr Dominique Rebreyend (LPSC/CNRS-IN2P3/UJF)
        Transparents
    • 11:00 13:00
      Detector R & D and Data Handling Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      • 11:00
        Experience with CMS Offline and Computing in LHC Runs 2010-2011 15m
        In this presentation we will discuss the experience with the CMS computing model during the LHC runs 2010-2011. We will outline how the experiment operations has evolved during the first few months of operations. The current state of the Offline and Computing projects will be presented and we will describe the initial experience with active analysis users and real data. We will include Tier0 processing, reprocessing steps on data and fast turn-around calibrations. We will address the issues that worked well in addition to identifying areas where future development and refinement are needed.
        Orateur: Jean-Roch Vlimant
        Transparents
      • 11:15
        Perfromance of the ATLAS Trigger and DAQ system 15m
        The ATLAS Trigger and Data Acquisition (TDAQ) system is responsible for reducing the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of 200 Hz. The ATLAS trigger is designed to select signal-like events from a large background in three levels: a first-level (L1) implemented in custom-built electronics, as well as the two levels of the high level trigger (HLT) software triggers executed on large computing farms. The first-level trigger is comprised of calorimeter, muon and forward triggers to identify event features such as missing transverse energy, as well as candidate electrons, photons, jets and muons. Input signals from these objects are processed by the L1 Central Trigger to form a L1 Accept (L1A) decision. L1A and timing information is consequently sent to all sub-detectors, which push their data to DAQ buffers. The first part of the HLT system (called Level 2) pulls the data from the buffers on demand, while the second part (called Event Filter) works with the whole event at hand. We will demonstrate that the ATLAS trigger performed smoothly throughout 2010 and 2011, evolving with increasing LHC luminosity in order to maintain a high selection efficiency whilst operating at an overall data acquisition efficiency of 96%. The ATLAS first-level trigger rate has already reached 40 kHz, roughly half of the design rate. Concurrently, the Level 2 and Event Filter rates reached and consequently exceeded the design performance. We will also discuss the achievements and problems encountered during the 2010 and 2011 data taking periods, with an overview of challenges and plans for adapting to the upcoming upgrade of LHC running.
        Orateur: Mme Eleanor DOBSON (CERN)
        Transparents
      • 11:30
        Distributed processing and analysis of ATLAS experimental data 15m
        The ATLAS experiment is taking data steadily since Autumn 2009, collecting close to 1 fb-1 of data (several petabytes of raw and reconstructed data per year of data-taking). Data are calibrated, reconstructed, distributed and analysed at over 100 different sites using the World-wide LHC Computing Grid and the tools produced by the ATLAS Distributed Computing project. In addition to event data, ATLAS produces a wealth of information on detector status,luminosity, calibrations, alignments, and data processing conditions. This information is stored in relational databases, online and offline, and made transparently available to analysers of ATLAS data world-wide through an infrastructure consisting of distributed database replicas and web servers that exploit caching technologies. This paper reports on the experience of using this distributed computing infrastructure with real data and in real time, on the evolution of the computing model driven by this experience, and on the system performance during the first two years of operation
        Orateur: M. Dario Barberis (Genoa University/INFN)
        Transparents
      • 11:45
        Results from the NA62 Gigatracker prototype: a lowmass and sub-ns time resolution silicon pixel detector 15m
        The Gigatracker (GTK) is a hybrid silicon pixel detector developed for NA62, the experiment studying ultra-rare kaon decays at the CERN SPS. Three GTK stations will provide precise momentum and angular measurements on every track of the high intensity NA62 hadron beam with a time-tagging resolution of 150 ps. Multiple scattering and hadronic interactions of beam particles in the GTK has to be minimized to keep background events at acceptable levels, hence the total material budget is fixed to 0.5% X0 per station. In addition the calculated fluence for 100 days of running is 2 × 1014 1 MeV neq/cm2, comparable to the one expected for the inner trackers of LHC detectors in 10 years of operation. These requirements pose challenges for the development of an efficient and low-mass cooling system, to be operated in vacuum, and on the thinning of read-out chips to 100 μm or less. The most challenging requirement is represented by the time resolution, which can be achieved by carefully compensating for the discriminator time-walk. For this purpose, two complementary read-out architectures have been designed and produced as small-scale prototypes: the first is based on the use of a Time-over-Threshold circuit followed by a TDC shared by a group of pixels, while the other uses a constant-fraction discriminator followed by an on-pixel TDC. The readout pixel ASICs are produced in 130 nm IBM CMOS technology and bump-bonded to 200 μm thick silicon sensors. The Gigatracker detector system is described with particular emphasis on recent experimental results obtained from laboratory and beam tests of prototype bump-bonded assemblies, which show a time resolution of less than 200 ps for single hits.
        Orateur: Dr sara garbolino (INFN)
        Transparents
      • 12:00
        A detector for the measurement of the ultrarare decay K+->pi+ nu nubar: NA62 at the CERN SPS 15m
        The NA62 experiment at CERN aims at the very challenging task of measuring with 10% relative error the Branching Ratio of the ultrarare decay of the K+ into pi+ neutrino and antineutrino, which is expected to occur only in about 8 out of 10^11 kaon decays. This will be achieved by means of an intense hadron beam, an accurate kinematical reconstruction and a redundant veto system for identifying and suppressing all spurious events. The good resolution on the missing mass in the decay is achieved using a performant beam tracker (Gigatracker) to measure the kaon momentum and with a spectrometer equipped with straw tubes operating in vacuum. Hermetic veto (up to 50 mrad) of the photon from pi0 decays is achieved with a combination of large angle veto (with a creative reuse of the old OPAL lead glass blocks), the NA48 LKr calorimeter and two small angle calorimeters to cover the angle down to zero. The identification of the muons and the consequent veto is performed by a fast hodoscope plane (used in the first level of the trigger to reduce the rate) and by a 18-meter, neon-filled RICH counter which is able to separate pions and muons in the momentum interval between 15 and 35 GeV. Particle identification in the beam (kaon-pion separation) is achieved with an hydrogen differential Cherenkov counter (CEDAR). The trigger for the experiment is based on a multilevel structure with a first level implemented in the readout boards and with the subsequent level done in software. The aim is to reduce the 10 MHz L0 rate to few KHz sent to the CERN computing center. Studies are underway to use GPU boards in some key point of the trigger system to improve the performance. The talk will review the layout of the detector and give an update on the construction status and prospects.
        Orateurs: Dr Paolo VALENTE (INFN Roma1) , Riccardo Fantechi (INFN Pisa and Cern)
        Transparents
      • 12:15
        The MICE beamline instrumentation (trackers and PID) for a precise emittance measurement 15m
        The International Muon Ionization Cooling Experiment (MICE) will carry out a systematic investigation of ionization cooling of a muon beam, for the future Neutrino Factory and the Muon Collider. As the emittance measurement will be done on a particle-by-particle basis, a sophisticated beam instrumentation is needed to measure both particle coordinates and timing vs RF in a harsh environment due to high particle rates, fringe magnetic fields and RF backgrounds. A PID system, based on three time-of-flight stations (with resolutions up to 50-60 ps), two Aerogel Cerenkov counters and a KLOE-like calorimeter (KL) has been constructed and has allowed the commissioning of the MICE muon beamline in 2010. It will be soon followed by an Electron Muon Ranger to determine the muon range at the apparatus downstream end and later by two tracker detectors to trace incoming particles inside two high-field superconducting solenoids. Detector performances will be shown and their use for the beamline characterization fully illustrated.
        Orateur: Dr Maurizio Bonesini (INFN Milano Bicocca)
        Transparents
      • 12:30
        The KLOE-2 detector upgrade at DAFNE 15m
        The KLOE experiment at the DAFNE e+e- collider of the Frascati Laboratories of INFN is about to start a second data-taking campaign (KLOE-2). The interaction region of DAFNE has been modified using a crabbed waist scheme. The KLOE-2 scientific program aims to further improve the precision studies on kaon and low energy hadron physics, e.g. CKM unitarity and lepton universality, CPT symmetry and quantum mechanics tests, low energy QCD and the contribution of hadron vacuum polarization to muon anomalous moment. The detector has been upgraded with small angle electron taggers to extend the physics program to gamma-gamma physics: two stations of LYSO crystal calorimeters read-out by SiPM for the detection of low energy e+/e- (LET), and two scintillator hodoscopes to detect high energy e+/e- (HET). The LET have been assembled, installed and integrated in the KLOE DAQ system for data taking. The Roman pots for the insertion of the HET stations have been realized, equipped with step-motors for the positioning inside the beam pipe, and used for housing test scintillators to measure the background levels. Further detector upgrades include the insertion near the interaction point of an inner tracker (IT) to improve the reconstruction performance for low momentum tracks. The adopted solution is a low-mass, fully cylindrical and dead-zone free GEM based detector. After three years of R&D the construction of the first layer has started, with the aim of completing the detector by middle of 2012. The front-end electronics is based on the GASTONE ASIC, specifically developed for this detector, a charge amplifier with digital output integrating 64 channels in one single chip. To increase acceptance for photons emitted at very small angles and to improve the reconstruction of photons hitting the DAFNE quadrupoles, small crystal calorimeters (CCALT) and tile calorimeters (QCALT) will be installed inside the KLOE-2 detector.
        Orateurs: Collaboration KLOE-2 (LNF-INFN) , Dr Dario Moricciani (INFN - Sez. Roma "Tor Vergata")
        Transparents
      • 12:45
        The Silicon Strip Tracker of the Fermi Large Area Telescope 15m
        The Large Area Telescope (LAT) is the main instrument onboard the Fermi Gamma-ray Space Telescope, an orbital observatory launched in low-Earth orbit on June 11 2008 to survey the high-energy gamma-ray sky. The LAT tracker/converter serves the twofold purpose of converting the incoming gamma-ray into an electron-positron pair and tracking the latter in order to measure the original photon direction. With its 73 square meters of single-sided silicon-strip detectors, read out by some 900,000 independent electronics channel, it is the largest solid-state tracker ever built for a space application. The tracker system operates on 160 W of conditioned power while achieving a single-plane hit efficiency in excess of 99% and a noise occupancy at the level of 1 channel per million. We describe the basic tracker design and the performance throughout the first three years of operation in orbit.
        Orateur: Dr Johan Bregeon (INFN-Pisa)
        Transparents
    • 11:00 13:00
      Flavour Physics and Fundamental Symmetries Oisans (Alpes Congès - Alpexpo)

      Oisans

      Alpes Congès - Alpexpo

      • 11:00
        Searches for Rare and Forbidden B and Charm Decays with BABAR 15m
        We present recent BABAR results of searches for rare decays with new physics sensitivity. In particular, we present the results of searches for B -> gammma gamma and the lepton and baryon number violating modes B->Lambda(c)l and B->K/pi tau l. We also describe recent searches for the charm decays D-> Xl+l-, D0 -> gamma gamma and D0->l+l-.
        Orateur: Eugeni Grauges
        Slides
      • 11:15
        Updated search for Bd/Bs-->mu+mu- decays at CDF 15m
        We report the latest results of a CDF search for B->mumu decays using 6.9/fb of data. Doubled statistics with respect to the previous iteration and several analysis improvement provide results that are the most sensitive from a single-experiment to date.
        Orateur: Thomas Kuhr
        Slides
      • 11:30
        Search for B_{s,d}->mumu with the CMS experiment 15m
        The rare decays B_{s,d}->mumu provide an excellent test of the flavor sector of the Standard Model with sensitivity to many new physics models. We report on a search for these decays with the CMS experiment using data collected until Summer 2011.
        Orateur: Urs Langenegger (PSI)
        Transparents
      • 11:45
        The search for the very rare decays B_(s,d)->mu+mu- at LHCb 15m
        Review of the search for the very rare decays $B^{0}_{s} \rightarrow \mu^+ \mu^-$ and $B^{0} \rightarrow \mu^+ \mu^-$ with the LHCb experiment is presented. These decays are suppressed within the Standard Model as they can only occur via helicity suppressed loop diagrams. However, their amplitudes can be significantly different in many New Physics scenarios, especially in those with an extended Higgs sector. Therefore, these decays are a sensitive probe of physics beyond the Standard Model. The data collected in 2010 ($\sim 37$ $pb^{-1}$ ) allowed LHCb to reach similar sensitivities to the existing limits from the CDF and D0 Collaborations. With the data accumulated so far in 2011 LHCb is entering uncharted territory.
        Orateur: Mme Justine Serrano
        Slides
      • 12:00
        Towards global analysis of b -> s l^+l^- decays 15m
        The final data sets of BaBar, Belle and CDF as well as the current run of LHCb are about to significantly improve the experimental knowledge on rare $B$-decays governed by b -> s l^+l^-$. In view of this, we will present new tests of the electroweak short-distance couplings in the Standard Model and beyond, including a general set of non-standard interactions. Especially, the angular analysis of B -> K^* (->K pi) l^+l^- provides a large number of new observables which allow to efficiently disentangle short-distance (new) physics from long-distance QCD effects. The potential to test the Standard Model and specific non-standard interactions will be discussed, focusing on the high-dilepton invariant mass region, which is complementary to the low-dilepton mass region. Results of a model-independent analysis are presented, using current constraints from B -> K l^+l^- and B -> K^* l^+l^- for both regions in combination with other rare B-decays.
        Orateur: Dr Christoph Bobeth (TU München - IAS/Excellence Cluster Universe, Germany)
        Slides
      • 12:15
        Exploring New Physics in the C7-C7' plane 15m
        The Wilson coefficient C_7 governing the radiative electromagnetic decays of B meson has been calculated to a very high accuracy in the Standard Model, but till date there is no convincing model-independent experimental bound on either the magnitude or the sign of C_7. In the present paper, we attempt at constraining both the magnitude and sign of C_7 using a systematic approach. We consider already measured observables like the branching ratios of B --> Xs mu+ mu- and B --> Xs gamma, the isospin and CP asymmetries in B --> K* gamma, as well as A_FB and F_L in B --> K* l+ l-. We also discuss the transverse observable A_T^(2) which, once measured, may help to disentangle some of the scenarios considered. We explore the constraints on C_7, C_9, C_10 as well as their chirality-flipped counterparts. Within our framework, we find that we need to extend the constraints up to 1.6 sigma to allow for the "flipped-sign solution" of C_7. The SM solution for C_7 exhibits a very mild tension if New Physics is allowed in dipole operators only.
        Orateur: Dr Sébastien Descotes-Genon (LPT Orsay)
        Transparents
      • 12:30
        Updated search for non-SM physics in B-->K(*)mu+mu- decays at CDF 15m
        We present updated measurements of branching fractions, polarization, and muon forward-backward asymmetry in B-->K(*) mu mu final states using 6.7/fb of data collected by the CDF detector. A search for Lambda_b --> Lambda mu mu decays will also be shown. The results are the most sensitive from a single experiment to date.
        Orateur: Dr Hideki Miyake (KEK, Tsukuba)
        Slides
      • 12:45
        Angular analysis of the decay Bd->K*mumu at LHCb 15m
        The first LHCb measurements of the decay Bd->K*mumu will be presented. In particular, the forward-backward asymmetry, fraction of K* longitudinal polarisation and partial branching fraction as a function of the di-muon invariant mass squared will be shown from 309pb-1 of the 2011 data.
        Orateur: Mitesh Patel
        Slides
    • 11:00 13:00
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 11:00
        Search for MSSM neutral and charged Higgs in ATLAS. 15m
        The search for the neutral Higgs boson(s) beyond the Standard Model is presented, based on the ATLAS data collected in 2011. A wide region of the MSSM parameter space is tested via searches for Higgs decays into two tau-leptons. Additionaly, the obtained results are interpreted in terms of the exclusion limits for the Standard Model-like Higgs boson production. The experimental observation of charged Higgs bosons would provide a clear signature of the physics beyond the Standard Model. The search for these particles is presented, based on the ATLAS data collected in 2011. Several final state topologies are explored, with Higgs bosons originating from the top-quark decays in top pair events and subsequently decaying into $\tau \nu$ or $c\bar{s}$.
        Orateur: Martin Flechl
        Slides
      • 11:15
        A Search For The Higgs Boson in the Mode H --> Tau Tau 15m
        We present results from a search for the Higgs Boson in the channel H --> Tau Tau with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at sqrt s = 7 TeV
        Orateur: Simone Gennai (CERN/INFN)
        Slides
      • 11:30
        Higgs search in the Higgs to bb channel 15m
        The decay of the Standard Model-like Higgs boson into bb is the dominant decay process in the region of low Higgs boson masses. The Higgs search in this channel requirese an associated heavy object, allowing for strong discrimination from the dominant multi-jet background processes. We present the status of the Higgs searches in the H->bb channel based on the ATLAS data collected so far in 2011.
        Orateur: Ricardo Goncalo
        Slides
      • 11:45
        Higgs search in the Higgs to gammagamma channel 15m
        The search for the Standard Model-like Higgs boson decaying to two photons is one of the best ways to identify a low mass Higgs boson at LHC. The results of the search in this channel are presented, based on the ATLAS data collected in 2011 and giving sensitivity exceeding any currently reported. The detailed analysis of the background contributions is included.
        Orateur: Marumi Kado
        Transparents
      • 12:00
        A Search For The Higgs Boson In The Channel H -->Gamma Gamma With The CMS Detector 15m
        We present results from a search for the SM Higgs Boson in the channel H --> Gamma Gamma with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at sqrt s = 7 TeV
        Orateur: Daniele del Re (Universita' "Sapienza" & INFN Rome)
        Transparents
      • 12:15
        Search for Higgs to ZZ (llll,llnunu,llqq) 20m
        The search for the Standard Model-like Higgs boson via its decays into two Z bosons is presented, based on the ATLAS data collected in 2011. The results obtained in the fully leptonic 'golden' decay channel cover a wide range of Higgs boson masses. Above 200 GeV, the sensitivity is highly improved using channels in which one of the Z bosons decays into neutrinos or hadrons. The good signal to background ratio makes these channels ideal for a discovery.
        Orateur: Konstantinos Nikolopoulos
        Slides
      • 12:35
        A search of the Higgs Boson in H->ZZ (4l, 2l2v, 2l2j) with the CMS detector 20m
        We present results from a search for the SM Higgs Boson in the channels H -> ZZ -> 4l, 2l 2nu and 2l2j with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at sqrt (s) = 7 TeV
        Orateur: Roberto Salerno
        Transparents
    • 11:00 13:00
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 11:00
        F_\pi, \Lambda_MS and the Chiral Condensate from Renormalization Group Optimized Perturbation 15m
        A recent extension of a variationally optimized perturbation method, combined with renormalization group properties in a straightforward way, can provide a series of approximations to nonperturbative quantities such as the chiral symmetry breaking order parameters. We apply this to evaluate, up to the third order in this modified perturbation, the ratio F_\pi/\Lambda_MS where F_\pi is the pion decay constant and \Lambda_MS the basic QCD scale in the MS scheme. We also obtain from a similar approach the chiral quark condensate. We compare our estimates of \Lambda_MS and the chiral condensate with recent lattice calculation results.
        Orateur: Dr Jean-Loic Kneur (LCC Montpellier)
        Transparents
      • 11:15
        Nucleon form factors and moments of nucleon generalized parton distributions in twisted mass lattice QCD 15m
        We present results on the nucleon electromagnetic/axial form factors, as well as the lower moments of the nucleon generalized parton distributions, within lattice QCD using two dynamical flavors of degenerate twisted mass fermions. Our simulations are performed on lattices with three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm, allowing the investigation of cut-off effects. The volume dependence is examined using simulations on two lattices of spatial length L=2.1 fm and L=2.8 fm. The simulations span pion masses in the range of 260-470 MeV. Our results are renormalized non-perturbatively and the values are given in the MS-scheme at a scale mu=2 GeV. The nucleon axial charge, magnetic moment, Dirac and Pauli radii are obtained in the continuum limit and chirally extrapolated to the physical pion mass allowing for a comparison with experiment. The consequences of our results on the spin carried by the quarks in the nucleon are also investigated.
        Orateur: Dr Martha Constantinou (University of Cyprus)
        Slides
      • 11:30
        Study of rare $\Upsilon(2S)$ transitions to charmonia and lower bottomonia with the Belle detector 15m
        We report a search for the rare hadron transitions $\Upsilon(2S) \to \eta,$ $\pi^0 \Upsilon(1S)$ from 158 million $\Upsilon(2S)$ decays collected with the Belle detector at KEK. The $\eta$'s are detected via their $\pi^0 \pi^+ \pi^-$ and $\gamma\gamma$ decay modes. The $\Upsilon(1S)$'s are detected via their exclusive decays to dileptons. A major challenge is represented by the discrimination of these rare transitions from peaking backgrounds due to the dominant decay modes: $\Upsilon(2S) \to \pi\pi \Upsilon(1S)$ and $\Upsilon(2S) \to \gamma \chi_{bJ} \to\Upsilon(1S)$. New branching ratio measurements on the two photon cascades via $\chi_{bJ}$ states will be discussed. The $\chi_{cJ}$ is detected in $\gamma J/\psi$ final states, and $\eta_c$ in hadronic final states. The X(3872) is searched for in $J/\psi \pi^+\pi^-$ and $J/\psi \pi^+\pi^-\pi^0$ final states, The X(3915) in $J/\psi \pi^+\pi^-$. We also searched for the Y (4140) and X(4350) in $J/\psi \phi$ mode. No significant signals of radiative transitions from $\Upsilon(2S)$ to charmonia and XYZ states have been found. Upper limits on all related branching ratios will be given.
        Orateur: Umberto Tamponi
        Transparents
      • 11:45
        First observation of the $h_b$(1P) and $h_b$(2P) bottomonium states and study of $\Upsilon$(5S) to Bottomonium decays 30m
        We report the observation of the $h_b(1P)$ and $h_b(1P)p$ spin-singlet bottomonium states produced in the reaction $e^+e^-\to h_b(1P)n\pi^+\pi^-$ with significances of $5.5\,\sigma$ and $11.2\,\sigma$, respectively. We find that $M[h_b(1P)]=(9898.25\pm 1.06^{+1.03}_{-1.07})\,\mathrm{MeV}/c^2$ and $M[h_b(1P)p]=(10259.76\pm0.64^{+1.43}_{-1.03})\,\mathrm{MeV}/c^2$, which correspond to measurements of the P-wave hyperfine splittings$\Delta M_{m HF}=(1.62\pm1.52)\,\mathrm{MeV}/c^2$ and $(0.48^{+1.57}_{-1.22})\,\mathrm{MeV}/c^2$, respectively. We also report measurements of the cross sections for $e^+e^-\to h_b(1P)n\pi^+\pi^-$ relative to the cross section for the $e^+e^-\to\Upsilon(2S)\pi^+\pi^-$ reaction and examine the Dalitz plots of $\Upsilon$(5S)$\to \Upsilon$(nS)$\pi^+\pi^-$ and $\Upsilon$(5S)$\to h_b$(mP)$\pi^+\pi^-$ decays and search for resonant substructure. These results are obtained from a $121.4\,{\rm fb}^{-1}$ data sample collected with the Belle detector near the $\Upsilon(5S)$ resonance at the KEKB asymmetric-energy $e^+e^-$ collider.
        Orateur: Jean Wicht
        Transparents
      • 12:15
        Recent BABAR Studies of Bottomonium States 15m
        We present a study of the radiative transitions from decays of the Y(2S) and Y(3S) resonances using photons that have converted into an e+e- pair, obtaining precise measurements of the branching fractions for chi_b1,2(1, 2P) --> gamma Y(1S) and chi_b1,2(2P) -->gamma Y(2S) transitions and search for radiative decay to the eta_b(1S) and eta_b(2S) states. We present a search for the spin-singlet partner of the chibJ(1P) triplet, the hb(1P) state of bottomonium in the transitions Y(3S)-->pi0 hb and Y(3S)-->pi+pi-hb using a data sample of 122 million Y(3S) events.
        Orateur: Elisa Guido
        Transparents
      • 12:30
        Charmonium and Charmonium-like States with BABAR 15m
        We present a search for the X(3872) produced in B-->psi pi+pi- K and B-->psi pi+pi-pi0 K (psi=J/psi or psi(2S)) using 427 fb-1 of BaBar data. We present updated mass and width measurements for the Y(4260)--> J/psi pi+pi- produced in Initial State Radiation events using 454 fb-1 of data. We report the study of the B meson decays B+--> J/psi phi K+ and B0--> J/psi phi K_S, and of charged and neutral B decays to chi_c1 K pi. We describe a detailed study of charmonium states produced in two-photon collisions and decaying to K_S K pi and K K pi pi pi0. We present a high statistics measurement of the mass and width of the etac(2S) state.
        Orateur: Elisa Guido
        Transparents
      • 12:45
        Recent results on hadrons via Initial State radiation at BABAR 15m
        We report on latest results obtained at BABAR studying low energy e+e- annihilations, produced via initial state radiation. Hadronic cross sections are the experimental input for calculation of the muon anomalous magnetic moment, while the study of the final states and intermediate structures with unprecedented accuracy can reveal new states and their properties. In particular, an updated measurement, using the total data set taken by BABAR, of the cross sections for e+e- -> h+h-h'+h'- (where h,h'=pi,K), and of the study of the Y(2175) --> phi f_0(980) resonance, will be presented.
        Orateur: Andreas Hafner
        Slides
    • 11:00 13:00
      Top and Electroweak Physics Stendhal

      Stendhal

      Alpes Congrès - Alpexpo

      Président de session: Dr Jan Stark (Stark)
      • 11:00
        Measurement of W and Z boson production cross sections in pp collisions at 7 TeV with the ATLAS detector 20m
        Differential and inclusive cross sections for electroweak boson production are presented, in the electron, muon and tau decay channels. The data are compared to the predictions of next-to-leading-order and, where available, next-to-next-leading order QCD.
        Orateur: Ryan Reece (University of Pennsylvania)
        Slides
      • 11:20
        Measurement of the properties of Electroweak bosons with the D0 detector 25m
        We present precision measurements of the properties of W and Z bosons using D0 data. These include a measurement of W boson mass using the electron decay channel and the charged asymmetry in the muo decay channel We also present a direct measurement of the W boson width using the events with large transverse mass and the mass dependence of the forward-backward charge asymmetry in $p\bar{p} \rightarrow Z/\gamma^{*} \rightarrow e^+e^-$ interactions.
        Orateur: Dr Hengne LI (LPSC)
        Slides
      • 11:45
        Measurement of W and Z boson production in association with jets and heavy flavours in pp collisions at 7 TeV with the ATLAS detector 20m
        Differential and inclusive cross sections for electroweak boson production in association with jets are presented, in the electron and muon decay channels. Inclusive jet distributions, multiplicities and ratios are presented, as well as measurements of jets containing B-hadrons. The data are compared to the predictions of next-to-leading-order.
        Orateur: Andrea Messina
        Slides
      • 12:05
        Measurement of rates of jets produced in association with W and Z bosons with the CMS detector 20m
        We present studies of the associated production of jets with vector bosons in pp collisions at 7-TeV center-of-mass energy at the LHC, based on data recorded by the CMS detector at the LHC in 2010 and 2011. The jet multiplicity distributions are efficiency corrected and unfolded. The studies extend to the measurement of b-jets in association with Z bosons, and of charm-jets in association with W bosons, which bring important information of the b and s-quark densities in the proton at LHC energies.
        Orateur: Mlle Monika Grothe (Univ. of Wisconsin)
        Transparents
    • 13:00 14:30
      Lunch 1h 30m les Ecrins

      les Ecrins

      Alpes Congrès - Alpexpo

    • 14:30 16:00
      Cosmology and Gravity Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 14:30
        CMB Power Spectrum Results from the South Pole Telescope 35m
        The South Pole Telescope (SPT) is a 10-meter telescope designed to survey the millimeter-wave sky. The telescope and its 960-element bolometric camera were successfully installed at the South Pole in 2007. Since then, the SPT has imaged 2200 square degrees of the sky with low noise and arcminute resolution. I will report on the CMB power spectrum results from SPT. In conjunction with data from the WMAP satellite, the new SPT data leads to a 6 sigma detection of gravitational lensing in the CMB. The SPT+WMAP data also improve constraints on the shape of the primordial power spectrum with implications for inflationary models. Finally, the SPT+WMAP data yield measurements of the primordial helium abundance and the number of relativistic particle species in the early Universe.
        Orateur: Dr Christian Reichardt (Dept. of Physics, University of California, Berkeley)
        Slides
      • 15:15
        The thermal Sunyaev-Zel'dovich effect with PLANCK 15m
        The PLANCK mission will provide the most precise mesurement of the cosmic microwave background (CMB) anisotropies in temperature and polarization, allowing us to set tight constraints on the cosmological parameters. In addition, the PLANCK mission, because of its frequency coverage, is sensitive to the interaction of CMB photons and hot electrons in galaxy clusters via the thermal Sunyaev-Zel'dovich (tSZ) effect. First, we present the reconstruction of the tSZ signal from a set of observed Planck maps at different frequency bands using an adapted component separation algorithm: MILCA. Second, we will discuss the construction and validation process of the Planck Early Sunayev-Zeldovich (ESZ) based catalogue of clusters of galaxies. This catalogue will allow us to study in details the matter content of the universe and therefore to measure the matter power spectrum as a function of redshift and the properties of matter filaments. Finally, we will demonstrate the complementarity of the PLANCK tSZ and X-ray observations of clusters of galaxies in order to caracterize the properties and spatial distribution of the hot gas of electrons in galaxy clusters and galaxy cluster systems. The measured pressure profiles in galaxy clusters will allow us to constrain large scale structure formation theories.
        Orateur: Guillaume Hurier (LPSC)
        Transparents
      • 15:35
        Semi-analytical computation of the non-linear matter power spectrum 15m
        I will discuss the new numerical implementation in CLASS of two semi analytical methods for computing the matter power spectrum, namely the one-loop and Time Renormalization Group method. I will present our result compared against accurate N-body simulation and the halofit method on the BAO region. I will also discuss about the new implementation of the one-loop method, showing a great improvement over the more commonly used one.
        Orateur: Benjamin Audren (EPFL)
        Transparents
    • 14:30 16:00
      Detector R & D and Data Handling Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      • 14:30
        The LHCb Upgrade Detector 15m
        The Letter of Intent of the LHCb upgrade has recently been submitted. Flavour physics probes beyond the energy frontier (a few TeV at the LHC), since it is sensitive to the effects of virtual quantum loop diagrams associated with particles that can be far heavier than those which can be produced directly. To exploit fully the flavour-physics potential of the LHC will require an LHCb upgrade. This will allow LHCb to operate the detector at higher luminosity and to collect 50 fb−1 of data integrated over around ten years of operation. A key feature of the upgrade will be to equip LHCb with 40MHz readout of all sub-detectors and a fully flexible software trigger. This will allow the selection of hadronic, as well as leptonic, final states in B and D decays at high luminosity and provide the flexibility for LHCb to serve as a general-purpose detector in the forward region. Detector upgrades such as a 50x50um pixel based vertex detector system, and a fibre tracking system and augmenting the RICH particle identification with a time-of-flight system are being considered. The relevant experience for the upgrade recently gained by operating the current detector at high luminosity will also be discussed.
        Orateur: Burkhard Schmidt
        Slides
      • 14:45
        Silicon Sensor and Detector Developments for the CMS Tracker Upgrade 15m
        CMS started a campaign to identify the future silicon sensor technology baseline for a new Tracker for the high-luminosity phase of LHC, coupled to a new effective way of providing tracking information to the experiment trigger. To this end a large variety of 6” wafers was acquired in different thickness's and technologies at HPK and new detector module designs were investigated. Detector thickness's ranging from 50µm to 300µm are under investigation on float zone, magnetic Czochralski and epitaxial material both in n-in-p and p-in-n versions. P-stop and p-spray are explored as isolation technology for the n-in-p type sensors as well as the feasibility of double metal routing on 6” wafers. Each wafer contains different structures to answer different questions, e.g. influence of geometry, Lorentz angle, radiation tolerance, annealing behaviour, validation of read-out schemes. Dedicated process test-structures, as well as diodes, mini-sensors, long and very short strip sensors and real pixel sensors have been designed for this evaluation. The structures will be exposed to fluences composed of protons and neutrons representing the mixture of charged hadrons and neutrons as expected in the CMS Tracker after an integrated luminosity of 3000/fb at several radii. At the same time simulation studies were performed on how identification of high-momentum particle tracks, as a part of the Level 1 Trigger, can be achieved by correlating hits on two closely spaced sensors (stacked modules), making use of their strip or pixel cluster widths and positions to estimate the track bending in the high CMS magnetic field. This contribution provides an overview of the individual sensor structures and their characteristics and of the construction of different types of stacked modules for trigger studies, and summarizes interesting measurements performed so far.
        Orateur: Raffaello D'Alessandro (Università di Firenze INFN-Firenze)
        Slides
      • 15:00
        ATLAS IBL: a challenging first step for ATLAS Upgrade at the sLHC 15m
        With the LHC collecting data at 7 TeV, plans are already advancing for a series of upgrades leading eventually to about five times the LHC design luminosity some 10 years from now in the high luminosity LHC (HI-LHC) project. The upgrades for the ATLAS detector will be staged in preparation for HI-LHC. The first upgrade for the pixel detector will be the construction of a new pixel layer which will be installed during the first shutdown of the LHC machine foreseen in 2013-14. The new detector, called the Insertable B Layer (IBL) will be installed between the existing pixel detector and a new, smaller radius beam-pipe at a radius of 3.2 cm. The IBL will require the development of several new technologies to cope with increased radiation and pixel occupancy and also to improve the physics performance through reduction of the pixel size and a more stringent material budget. Two different and promising silicon sensor technologies, planar n-in-n and 3D, are currently under investigation for the IBL. An overview of the IBL module design and the qualification for these sensor technologies with particular emphasis on irradiation and beam tests will be presented. This talk will also summarize the improvements expected to the ATLAS detector at the HI-LHC.
        Orateur: M. Alessandro La Rosa (University of Wisconsin)
        Slides
      • 15:15
        A Novel Pixel Vertex Detector for the Belle II Experiment at SuperKEKB 15m
        With the completion of the first-generation experiments at asymmetric $e^+ e^-$ colliders (BaBar and Belle) studying CP violation in the B-meson system, a new era of high luminosity machines is at the horizon. We report here on the plans for future experiments on CP violation and searches for physics beyond the Standard Model at the upgraded KEKB machine in Japan (``SuperKEKB''), providing an almost two orders of magnitude higher instantaneous luminosity. Due to the much higher backgrounds expected at SuperKEKB, a massive upgrade of the Belle detector (``Belle II'') is necessary. In particular, the tracking detectors, the Central Drift Chamber and the Silicon strip vertex detector need to be replaced. Due to the expected large occupancy close to the beam pipe a pixel detector is mandatory at SuperKEKB for the precise vertex determination. We report here on the design and construction of a novel silicon pixel detector for Belle II, based on the DEPFET-technology. The DEPFET (``depleted p-channel field effect transistor'') pixel provides a high signal to noise ratio and therefore allows for thin sensors, down to 50 microns. The principles of the DEPFET technology will be explained as well as the construction of large pixel matrices where the readout ASICs are mounted at the ends of the sensors, outside of the acceptance region for particle detection. The sensors are monolithic and self-supporting and are arranged in two layers to make up the detector structure. Some details concerning the readout, mechanics and cooling schemes are also presented. Finally, we show some simulations on the expected performance of this unique vertex detector, which should be ready for installation in Belle II by the end of 2014.
        Orateur: Christian Kiesling (Max-Planck-Institute for Physics)
        Transparents
      • 15:30
        CMOS sensors with high resistivity epitaxial layer 15m
        CMOS Pixel Sensors (CPS) are foreseen to equip vertex detectors where priority is given to granularity, material budget and power consumption, potentially at the expense of read-out speed and radiation tolerance. Being initially developed for an experiment at the ILC, the sensors came out to be well suited to Heavy Ion Collision experiments (STAR at RHIC, CBM at FAIR, ...) and their intrinsic potential offers attractive perspectives for the vertex detector to be operated at the SuperB factory. Another trend motivating their continuous development concerns trackers, where granularity is less an issue but material budget, power consumption and fabrication costs may be significantly reduced when using CMOS pixel sensors intead of usual semi-conducting devices.    For many years, CPS were manufactured with commercial wafers featuring exclusively low resistivity (i.e. typically 10 ohm.cm) epitaxial layers. The interest of industry for high resistivity epitaxial layers is a rather recent event, with a considerable impact on the potential of the CPS (e.g. a typical signal-to-noise ratio of about 35-40). Several sensors were fabricated since early 2010 with a 400 ohm.cm resistivity epitaxial layer, available in a 0.35 mum process, and tested on particle beams. Their detection performances were assessed extensively, mainly in perspective of their implementation in the two internal layers of the STAR-HFT. Featuring a total material budget per layer of 0.37 % of radiation length, the HFT is foreseen to start data taking in 2013/2014.    The talk will summarise the test results of the STAR-HFT sensor and provide insight of the next steps of the R&D, which are based on an emerging CMOS technology using a 0.18 mum feature size and offering a >= 1 kohm.cm epitaxy. Moreover, the development of a very light ladder equipped on both faces with 50 mum thin sensors, as well as supportless pixelated systems featuring < 0.15 % of radiation length, will be described. Finally, the evolution of the R&D, exploiting specific features of the 0.18 mum technology, will be overviewed, including a large area beam telescope for the EU-FP7 project AIDA.
        Orateur: Dr auguste besson (Institut Pluridisciplinaire Hubert Curien)
        Slides
      • 15:45
        Diamond for high energy radiation and particle detection 15m
        Progress in experimental particle physics in the coming decade depends crucially upon the ability to carry out experiments at high energies and high luminosities. These two conditions imply that future experiments will take place in very high radiation areas. In order to perform these complex and perhaps expensive experiments new radiation hard technologies will have to be developed. Chemical Vapor Deposition (CVD) diamond is being developed as a radiation tolerant material for use very close to the interaction region where detectors may have to operate in extreme radiation conditions. During the past few years many CVD diamond devices have been manufactured and tested. As a detector for high radiation environments CVD diamond benefits substantially from its radiation hardness, very low leakage current, low dielectric constant, fast signal collection and ability to operate at room temperature. As a result CVD diamond now has been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of e+e- colliders (BaBar and Belle experiments) and hadron colliders (CDF and every experiment at the recently commissioned CERN Large Hadron Collider). In addition, CVD diamond is now being considered as a sensor material for the particle tracking detectors closest to the interaction region where the most extreme radiation conditions exist. We will present the present state-of-the-art of polycrystalline CVD diamond and the latest results obtained from detectors constructed with this material. Recently single crystal CVD diamond material has been developed which resolves many of the issues associated with polycrystalline material. We will also present recent results obtained from devices constructed from this new diamond material. Finally, we will discuss the use of diamond detectors in present and future experiments and their survivability in the highest radiation environments.
        Orateurs: Harris Kagan (The Ohio State University) , William Trischuk (University of Toronto)
        Transparents
    • 14:30 16:00
      Flavour Physics and Fundamental Symmetries les Ecrins 3

      les Ecrins 3

      Alpes Congrès - Alpexpo

      • 14:30
        Charmonium and X, Y, Z at Belle 15m
        We report results of a study of charmonium and X, Y, Z states using the world-largest data sample accumulated with the Belle detector at the KEKB asymmetric-energy e+e- collider. : We present results from a study of $X(3872) \to J/\psi \pi^+ \pi^-$ decays produced in exclusive $B\to K \pi^+ \pi^- J/\psi$ decays using the full Belle data set. We present new measurements of the $X(3872)$ mass and width and the $BF(B \to K X(3872)) \times BF(X(3872) \to \pi^+ \pi^- J/\psi)$ product branching fractions for both charged and neutral $B$ mesons. A new measurement of the difference in mass between $X(3872) \to \pi^+ \pi^- J/\psi$ signals in $B^+$ and $B^0$ decays and results of a search for a charged partner of the $X(3872)$ in the decay $B \to K X^+, X^+ \to \pi^+ \pi^0 J/\psi$ are reported. In addition, we examine possible $J^{PC}$ quantum number assignments for the $X(3872)$ based on comparisons of angular correlations among final state particles in $X(3872) \to \pi^+ \pi^- J/\psi$ decays with simulated data for $J^{PC}$ values of $1^{++}$ and $2^{-+}$. We examine the influence of $\rho-\omega$ interference in the $M(\pi^+\pi^-)$ spectrum. The analysis is based on a 711 fb$^{-1}$ data sample that contains 772 million $B\bar{B}$ meson pairs collected at the $\Upsilon(4S)$ resonance in the Belle detector at the KEKB collider. We report a study of $B\to (J/\psi \gamma) K$ and $B\to (\psi' \gamma)K$ decay modes using $772\times 10^{6}$ $B\overline{B}$ events collected at the $\Upsilon(4S)$ resonance. We observe $X(3872) \to J/\psi \gamma$ and report the first evidence for $\chi_{c2} \to J/\psi \gamma$ in $B\to (X_{c\overline{c}}\gamma) K$ decays, while in a search for $X(3872) \to \psi' \gamma$ no significant signal is found. We measure the cross section for $e^+e^- \to \pi^0 \pi^0 J/\psi$ from threshold up to 6 GeV using initial state radiation events from $e^+e^-$ annihilation at $\sqrt{s}=10.58$ GeV. We reconstruct the $J/\psi$ in its di-muon decay mode. Using this data we search for evidence of $Y(4260)$ decaying to $\pi^0 \pi^0 J/\psi$. This analysis is based on a data sample with an integrated luminosity of 791 fb$^{-1}$ collected with the Belle detector. We present the results of an amplitude analysis of the $\bar{B}^0 \to J/\psi K^- \pi^+$ decays. A search for charged charmonium-like states in the $J/\psi \pi^+$ system has been performed. We have measured the helicity amplitudes of the resonances in the $K^- \pi^+$ system. The analysis is based on 711 fb$^{-1}$ data sample collected by the Belle detector. We report the results of a study of $B^{\pm}\to K^{\pm}\eta_c$ and $B^{\pm}\to K^{\pm}\eta_c(2S)$ decays followed by $\eta_c$ and $\eta_c(2S)$ decays to $(K_S K\pi)^0$. The results are obtained from a data sample containing 535 million $B\bar{B}$-meson pairs collected in the Belle experiment. We measure the products of the branching fractions ${\mathcal B}(B^{\pm}\to K^{\pm}\eta_c){\mathcal B} (\eta_c\to K_S K^{\pm}\pi^{\mp})$ and ${\mathcal B}(B^{\pm}\to K^{\pm}\eta_c(2S)) {\mathcal B}(\eta_c(2S)\to K_S K^{\pm}\pi^{\mp})$. Interference with the non-resonant component leads to significant model uncertainty in the measurement of these product branching fractions. Our analysis accounts for this interference and allows the model uncertainty to be reduced. We also obtain the masses and widths of the above mentioned charmonia. In the $\eta_c(2S)$ case the results are significantly affected by the interference and also include a model uncertainty. The subject of this analysis is the $Y(3940)$ enhancement at about 3940 MeV. The mass and decay width have been determined by the Belle collaboration upon discovery and were later confirmed by BaBar. Additional quantum numbers, however have not been measured yet. The decay channels, used in this analysis are $B^0 \to J/\psi \omega K^0_S$ and $B^+ \to J/\psi \omega K^+$ (and charge conjugate). $J^{PC}$ shall be determined through an angular distribution analysis of Belle data equivalent to 711 fb$^{-1}$, as well as improvements made in mass and decay width measurements. With a better understanding of the resonances quantum numbers, hopefully statements regarding its theoretical interpretation can be made.
        Orateur: Mlle Anna Vinokurova (Budker Institute)
        Transparents
      • 14:45
        Recent results from the KEDR detector at the VEPP-4M e+e- collider 15m
        We report results from the KEDR detector operating at the VEPP-4M electron-positron collider in the Budker Institute in Novosibirsk. They include: high-precision measurements of J/psi, psi' and tau lepton masses as well as determination of the main parameters of the psi(3770) resonance.
        Orateur: Dr Evgeny Baldin (Budker Institute)
        Slides
      • 15:00
        Recent Results from BESIII 15m
        In July 2008 the BESIII experiment in Beijing recorded the first hadronic event from e+e- collisions at the BEPCII storage ring. Since then over 100 million psi(2S) and over 200 million J/psi events, as well as a data sample corresponding to an integrated luminosity of about 2.9fb-1 at the psi(3770) resonance have been accumulated. This provides the opportunity to improve the precision on many existing measurements in the charm region and has led to striking new results in the light quark sector. The talk reviews recent results focusing on the first two years of BESIII operation and previews future expectations.
        Orateur: Prof. Liaoyuan Dong (Institute of High Energy Physics, Beijing)
        Slides
      • 15:15
        Other B decays at Belle 15m
        We report measurements of branching fractions and $CP$ violation asymmetries for $B\to \phi\phi K$ decays. Results of the study of $B^{\pm}\to J/\psi K^{\pm}$ and $B^{\pm}\to\eta_C K^{\pm}$, that result in a final state of five kaons, will also be presented. We study the $B^-$ meson decays to the final state of $\overline{p} \Lambda D^0$. The decay $B^-\to\overline{p} \Lambda D^{*0}$ is observed for the first time, with the invariant mass of the $\overline{p}\Lambda$ system peaking near threshold. Furthermore, we set an upper limit on decay branching fraction of $B^-\to\overline{p}\Lambda D^{*0}$ in absence of a statistically significant signal. We report a study of the exclusive $B$ meson decays to the final states $D_s K^0_S\pi$ and $D_s KK$. We use $D_s^- \to\phi\pi^-$, $\bar{K}^*(892)^0 K^-$ and $K^0_S K^-$ decay modes for the $D_s$ reconstruction. The HyperCP experiment at Fermilab reported the observation of three events for $\Sigma \rightarrow p \mu^+\mu^-$ decay. The dimuon masses of the observed events are clustered within detector resolution of 1 MeV/$c^2$, around 214.3 MeV/$c^2$. These decays might be interpreted as a two-body decay, $\Sigma^+ \rightarrow p X^0(214)$, $X^0(214) \rightarrow \mu^+\mu^-$. Several theoretical papers interpret the $X^0(214)$ as a sgoldstino in SUSY model, a light Higgs boson in NMSSM model, or an U-boson. We report on a search for the $X^0$ particle in $B^0$ to $K^+(\pi^+)\pi^ -X^0$ decays. We extend the search to a mass region from 212 MeV/$c^2$ to 500 MeV/$c^2 $ with several different $X^0$ lifetime assumptions. We measured the branching fraction of the decay $B^0 \to J/\psi \eta^{ (')}$ based. The branching fraction results were used to constrain the $\eta$-$\eta'$ mixing angle. These analyses are performed using the large data sample collected with the Belle detector near the $\Upsilon(4S)$ resonance at the KEKB asymmetric $e^+e^-$ collider.
        Orateur: Dr Min-Zu Wang (NTU, Taipei)
        Slides
      • 15:30
        Observation of the X(3872) state at CMS 15m
        A measurement of the ratio of X(3872) and \psi(2S) signal yields in pp collisions at 7 TeV is presented, using data recorded with the CMS experiment in 2010. The corresponding integrated luminosity is 36/pb. X and Psi(2S) decays are reconstructed in the final state $J/\psi \pi^+ \pi^-$, with the subsequent decay of the $J/\psi$ into two muons. The measured ratio is compared to theoretical expectations. In this talk we present preliminary measurements of the Bc mass and lifetime in the J/Psi+pion decay performed with the CMS experiment. The lifetime is measured for the first time using a fully kinematically reconstructed channel; Unlike previous measurements from the Tevatron, the fully reconstructed channel does not require corrections for undetected neutrinos from Monte Carlo simulation.
        Orateur: Dr Daniele Fasanella (INFN and University of Bologna)
        Slides
      • 15:45
        Studies of bottom baryons at CDF 15m
        Using 4.2 fb^-1 of data collected by the displaced track trigger, we report the observation of the Xi_b^-  baryon  through its hadronic decay into a Xi_0c pi- final state and a measurement of its mass.   In addition, we report the results of a search for the Xi_b^0  baryon.
        Orateur: Dr Peter Bussey (University of Glasgow)
        Slides
    • 14:30 16:00
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 14:30
        Search for Higgs to WW (lnulnu,lnuqq) 15m
        The search for the Standard Model-like Higgs boson via its decays into two W bosons is presented, based on the ATLAS data collected in 2011. The search in the dilepton final state is more powerful than any public result for intermediate mass Higgs bosons and has the highest sensitivity of any of the LHC Higgs searches. It is complemented by semi-leptonic WW decays which give good performance in the region of high Higgs boson masses.
        Orateur: Jonas Strandberg
        Slides
      • 14:45
        A search for the Higgs boson in H->WW->2l2nu mode with the CMS detector 15m
        We present results from a search for the SM Higgs Boson in the channel H -> WW -> 2l 2nu with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at sqrt s = 7 TeV. A Higgs signal in the Vector Boson Fusion channel, by exploiting the distinctive signature of the events, where the Higgs decay is accompanied by two high rapidity jets, is also presented.
        Orateur: M. Dmytro Kovalskyi (UCSB/CERN)
        Transparents
      • 15:20
        Combined Results on SM Higgs Search With The CMS Detector 20m
        We report on the combined results from several searches for the SM Higgs boson conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.
        Orateur: Andrey Korytov
        Transparents
      • 15:40
        The global electroweak fit and constraints on new physics 15m
        In the global fit of the Standard Model using Gfitter, electroweak precision observables as well as constraints from direct Higgs searches are compared with state-of-the-art electroweak predictions. We use the most recent results for direct Higgs searches, including updates on precision measurements such as MW and mtop from Tevatron and LHC experiments. Moreover, the Gfitter results for the oblique parameters are presented coherently together with constraints on various new physics models, including Little Higgs models, Extra Dimensions, Technicolour and Four Generations.
        Orateur: Dr Matthias Schott (CERN)
        Transparents
    • 14:30 16:05
      Neutrino Physics Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 14:30
        Results and physics implications of the precision measurement of the 7Be solar neutrino flux performed with the Borexino detector 15m
        Borexino is a massive, calorimetric liquid scintillator detector installed at the underground Gran Sasso Laboratory. With its unprecedented radiopurity levels achieved in the core of the detection medium, it is the only real time experiment in operation able to study solar neutrino interactions in the challenging sub-MeV energy region. The recent precise measurement of the 7Be solar neutrino flux, characterized by a total uncertainty amounting to less than 5 %, will be described, as well as the accurate determination of the corresponding day/night asymmetry. These results, besides constituting the most precise experimental evaluations concerning low energy solar neutrinos obtained to date, provide also a unique opportunity to probe and validate the favored neutrino oscillation paradigm in the so far untested Vacuum regime. Furthermore, they have also important implications in term of allowed regions in the oscillation parameters space. Other very interesting outcomes of the experiment, specifically the low threshold investigation of 8B solar neutrinos and the detection of geo-neutrinos from the Earth, will be summarized, too. Finally, the potential physics reach of a neutrino/anti-neutrino source measurement in Borexino will be highlighted, with special emphasis to its impact in the current experimental scenario characterized by several intriguing hints of possible short baseline oscillations involving eV scale sterile neutrinos.
        Orateur: Dr Gioacchino Ranucci (INFN)
        Slides
      • 14:45
        Measurement of ν̅e-e- Scattering Cross-Section and Constraints on New Physics with a CsI(Tl) Crystal Array at the Kuo-Sheng Reactor Laboratory 15m
        The ν̅e-e- elastic scattering cross-section was measured with a CsI(Tl) scintillating crystal array having a total mass of 187 kg. The detector was exposed to an average reactor neutrino flux of 6.4 × 1012 cm-2s-1 at the Kuo-Sheng Nuclear Power Station in Taiwan. The experimental design, conceptual merits,detector hardware, data analysis and background understanding of the experiment will be discussed. We will present final resuls with 29882/7369 kg-days of Reactor ON/OFF data, on the cross-section and the standard electroweak parameters sin2W and (gV,gA) measurements, the test on charged-current neutral-neutral interference, as well as limits on neutrino magnetic moments and charge radius squared [1]. We will also present constraints on non-standard interactions (NSI) of neutrino and Unparticle Physics (UP) in ν̅e-e- interaction channel [2] based on this data set as well as our previous data sets with ULE-HP Ge detectors which were used for the measurements of neutrino magnetic moment [3] and Dark Matter, WIMP searches [4]. [1] “Measurement of Neutrino-Electron Scattering Cross-Section with a CsI(Tl) Scintillating Crystal Detector Array at the Kuo-Sheng Nuclear Power Reactor”, M. Deniz et al., Phys. Rev. D 81, 072001 (2010). [2] “Constraints on nonstandard neutrino interactions and unparticle physics with ν̅e-e- scattering at the Kuo-Sheng nuclear power reactor”, M. Deniz et al., Phys. Rev. D 82, 033004 (2010). [3] “New limits on spin-independent and spin independent couplings of low-mass WIMP dark matter with a germanium detector at a threshold of 200 eV”, S.T. Lin et al., Phys. Rev. D 79, 061101(R) (2009). [4] “Search of Neutrino Magnetic Moments with a High-Purity Germanium Detector at the Kuo-Sheng Nuclear Power Station”, H. T. Wong et al., Phys. Rev. D 75, 012001 (2007).
        Orateur: M. Bilmis Selcuk (Middle East Technical University, Ankara, Turkey)
        Slides
      • 15:00
        Review of Neutrino Event Generators 20m
        Neutrino event generators play an important role in the design and execution of neutrino experiments. In this talk I will describe several programs that simulate neutrino-nucleus interactions in the 1-100 GeV energy regime, focussing in particular on a discussion of the underlying physics models and identifying key assumptions.
        Orateur: Prof. Hugh Gallagher (Tufts University)
        Slides
      • 15:20
        Status of ICARUS T600 at LNGS 15m
        ICARUS-T600 is the first example of an innovative detection technology, the liquid Argon TPC, which is a sort of "electronic bubble chamber", potentially scalable to huge masses. The excellent topology reconstruction, tracking and particle identification capabilities, together with the calorimetric measurement of deposited energy, make the LAr-TPC an ideal detector for the study of rare events such as neutrino interactions and nucleon decay. With a mass of 600 tons, ICARUS is the largest LAr-TPC ever built. It has been installed at the Gran Sasso underground laboratory and has been taking data since May 2010. ICARUS is performing a broad physics programme, mainly centered on the study of the neutrinos in the CNGS beam from CERN, but also including neutrinos from natural sources. The characteristics and performance of LAr-TPCs will be illustrated, and first results from the physics runs of ICARUS-T600 in 2010 and 2011 will be shown; future projects based on LAr-TPCs, especially concerning the search for sterile neutrinos, will also be discussed.
        Orateur: Dr Filippo Varanini (INFN Padova)
        Transparents
      • 15:35
        Updated results of the OPERA long baseline neutrino experiment 15m
        The OPERA neutrino detector built in the underground Gran Sasso Laboratory is designed to detect muon-neutrino to tau-neutrino oscillations in direct appearance mode. The hybrid apparatus consists of an emulsion/lead target complemented by electronic detectors. It is placed in the long-baseline CERN to Gran Sasso neutrino beam (CNGS) 730 km away from the source. The experimental set-up and ancillary facilities used to extract data recorded in the emulsion will be described, with the special procedures used to locate the interactions vertices and detect short decay topologies. OPERA is taking data since 2008. A first nu-tau interaction candidate was already published in 2010. An improved analysis scheme associated with a more detailed simulation has been developed and new results with increased statistics will be presented.
        Orateur: Dr DUSINI Stefano (Padova University and INFN)
        Slides
      • 15:50
        Measurement of charged kaons and pions production in proton-carbon interaction at 31 GeV/c from NA61/SHINE 15m
        An overview of the recent NA61/SHINE results on determination of charged kaon and pion yields in proton-carbon reactions is presented. The results aim to improve predictions of the neutrino flux in the T2K experiment. The data were recorded during the first physics run of NA61 in 2007 where a proton beam of 31 GeV/c momentum scattered off a graphite target. Thin target, 4% of a nuclear interaction length, was used to determine interaction cross section. Inclusive production cross sections for negatively and positively charged pions and kaons are presented as a function of laboratory momentum and polar angle. The spectra are compared to predictions of hadron production models. In addition preliminary results obtained with a long graphite target (the so called T2K replica target) are presented. The precision required by T2K is discussed.
        Orateur: Dr Alexander Korzenev (Universite de Geneve, Section de physique, DPNC)
        Transparents
    • 14:30 16:00
      QCD Bayard

      Bayard

      Alpes Congrès - Alpexpo

      • 14:30
        Quarkonium Production at LHCb 15m
        LHCb is one of the four LHC experiments that started collecting pp collisions in 2010 at a centre-of-mass energy of 7 TeV. With its forward geometry, LHCb is dedicated to the study of heavy-flavor production and decay. The copious production of quarkonia at large rapidity is a powerful tool to study quarkonium production as well as the performance of the detector providing fundamental building blocks for more sophisticated analyses such as searches for new physics in rare decays. We present results on J/Psi, Chi_c and Upsilon production. All the results will be interpreted in the framework of several theory models, and their impact on quarkonium production will be discussed.
        Orateur: M. Yanxi ZHANG (TUHEP)
        Transparents
      • 14:45
        Center-symmetric effective theory for two-color QCD with massive quarks at nonzero chemical potential 15m
        We revisit the center-symmetric dimensionally reduced effective theory for two-color Yang-Mills theory at high temperature. This effective theory includes an order parameter for center symmetry breaking/restoration and thus allows to broaden the range of validity of the conventional three-dimensional effective theory (EQCD) to lower temperatures, towards the confining phase transition. We extend the previous results by including in the effective theory the effects of massive quarks with nonzero baryon chemical potential. The parameter space of the theory is constrained by leading-order matching to the Polyakov loop effective potential of two-color QCD. Two-color QCD has attracted considerable interest due to the absence of the sign problem, and hence the possibility to probe its phase diagram at nonzero baryon density using standard Monte Carlo simulations. Our effective theory can provide model-independent predictions for the physics above the deconfinement transition, thus bridging the gap between large-scale numerical simulations and semi-analytical calculations within phenomenological models.
        Orateur: Dr Tomas Brauner (Bielefeld University)
        Slides
      • 15:00
        Measurement of J/Psi and Psi(2S) production at \sqrt{s}=7 TeV with the CMS experiment 15m
        This talk presents the J/psi and psi(2S) differential cross sections in pp collisions at 7 TeV, as a function of transverse momentum and in several rapidity ranges, on the basis of the 2010 data collected by CMS. The B to J/psi and B to psi(2S) fractions will also be presented, and compared to other measurements as well as to theory calculations.
        Orateur: Fabrizio Palla
        Transparents
      • 15:15
        Spectrum of quarks in QCD2 15m
        Using an exact integrodifferential equation, the spectral properties of the gauge invariant quark two-point Green's function are analyzed in two-dimensional QCD in the large N_c limit. The singularities of the Green's function arise from contributions of the colored sector of quarks (here in the fundamental representation) and give information about their spectrum. The problem is solved analytically. The Green's function is found to be infrared finite. The singularities are located on the positive real axis of the momentum squared and are represented by a denumerable infinite number of threshold type branch points with power -3/2 starting at positive mass values, which lie from a minimal value up to infinity. The emergence of strong threshold singularities is an indication that quarks could not be observed as free asymptotic states. Reference: Phys. Rev. D 81, 114008 (2010); arXiv, 1003.5099 [hep-ph].
        Orateur: Dr Hagop Sazdjian (IPN, Universite Paris-Sud 11, Orsay)
        Slides
      • 15:30
        J/Psi Photoproduction at HERA with ZEUS 15m
        The proton-dissociative diffractive photoproduction of J/psi mesons has been studied in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 112 pb. The cross section is presented as a function of the photon-proton centre-of-mass energy and of the squared four-momentum transfer at the proton vertex. The results are compared to perturbative QCD calculations. The double differential inelastic J/psi photoproduction cross section as function of the squared transverse momentum of the J/psi in bins of the inelasticity z has been measured. An integrated luminosity of 468 pb-1 was used corresponding to the full data sample collected by the ZEUS experiment. The events were required to have 0.1 < z < 0.9, pt > 1 GeV and 60 < W < 240 GeV, where pt is the transverse momentum of the J/psi and W is the photon-proton centre-of-mass energy. The J/psi mesons were identified through their decay into muon pairs. The double differential cross section measurements are compared to the most recent theoretical predictions.
        Orateur: Riccardo Brugnera
        Slides
      • 15:45
        Singlet Contribution to the Vector Correlator 15m
        We compute, for the first time, the order alpha_s^4 contribution to the singlet Adler function for the case of a genereric colour gauge group. Giving access to the terms proportional to the squared sum of the quark charges, this result completes the alpha_s^4 corrections to the familiar R-ratio as measured in electron-positron annihilation. Adopting the colour factors to the U(1) group, the full five-loop QED beta-function is completed. An independent calculation leads to the singlet contribution of order alpha_s^4 to the Gross-Llewellyn Smith sum rule. Relating Adler function and sum rule through the generalized Crewther relation leads to two non-trivial constrains which are indeed fullfilled. This cross check gives additional confidence in the correctness of this highly complicated calculation.
        Orateur: Johann Kuehn (KIT)
        Slides
    • 14:30 16:00
      Top and Electroweak Physics Stendhal

      Stendhal

      Alpes Congrès - Alpexpo

      Président de session: Massimo Passera
      • 14:30
        Two-Loop Mixed QCD-EW Virtual Corrections to the Drell-Yan Production of Z and W bosons 20m
        Drell-Yan production of Z and W bosons is a very important process for physics studies at hadron colliders. At the moment, the theoretical prediction includes the NNLO calculation in QCD, together with the resummation of logarithmic terms coming from soft gluon emission up to the next-to-next-to-leading logarithmic accuracy. In the talk, I will present the analytic calculation of the mixed alpha alpha_S two-loop virtual corrections.
        Orateur: Roberto Bonciani (LPSC)
        Slides
      • 14:50
        Measurement of high-Q2 charged current deep inelastic scattering cross sections with a longitudinally polarised positron beam at HERA 15m
        Measurements of the cross sections for charged current deep inelastic scattering in e+p collisions with a longitudinally polarised positron beam are presented. The measurements are based on a data sample with an integrated luminosity of 132 pb-1 collected with the ZEUS detector at HERA in 2006 and 2007 at a centre-of-mass energy of 318 GeV. The total cross section is presented at positive and negative values of the longitudinal polarisation of the positron beams. The single-differential cross sections dsigma/dQ2, dsigma/dx and dsigma/dy are presented for Q2 > 200 GeV2. The reduced double-differential cross section sigma_r is presented in the kinematic range 280 < Q2 < 30 000 GeV2 and 0.0078 < x < 0.42. The cross section measurements agree well with the predictions of the Standard Model. The results are used to determine a lower limit on the mass of a hypothetical right-handed W boson.
        Orateur: Trevor Stewart (DESY)
        Slides
      • 15:05
        Measurement of High-Q^2 Neutral Current Deep Inelastic e^+p Scattering Cross Sections with a Longitudinally Polarised Electron Beam at HERA 15m
        The cross sections for neutral current deep inelastic scattering in e+p collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The single-differential cross-sections dsigma/dQ^2, dsigma/dx and dsigma/dy and the double-differential cross sections in Q^2 and x are measured in the kinematic region Q^2 > 185 GeV^2 for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 136 pb^-1 taken in 2006 and 2007 at a centre-of-mass energy of 318 GeV. The structure functions xF_3 and xF_3^{\gammaZ} are determined by combining the e+p results presented in this analysis with previously measured e-p neutral current data. The measured cross sections are compared to the predictions.
        Orateur: Trevor Stewart (DESY)
        Slides
      • 15:20
        Combined Electroweak and QCD Fit of Inclusive Neutral and Charged Current Data with Polarized Lepton Beams at HERA 30m
        Using the deep inelastic e+p and e-p neutral and charged current scattering cross sections, including data with polarised electron beams, a combined electroweak and QCD analysis is performed to determine vector and axial-vector couplings vq and aq of light quarks u and d to the Z0 boson accounting for their correlation with parton distributions. The precision has been improved in particular for vector couplings with respect to the published results based on the unpolarized HERA data only. The determinations from HERA are compared with those from LEP and Tevatron.
        Orateur: Eram Rizvi
        Slides
    • 16:00 16:30
      Tea 30m Lobby

      Lobby

      Alpes Congrès - Alpexpo

    • 16:30 18:30
      Cosmology and Gravity Berlioz

      Berlioz

      Alpes Congrès - Alpexpo

      • 16:30
        Gravitational Energy in Massive Gravity 15m
        In GR the static gravitational potential of a self-gravitating body goes as 1/r at large distances and any slower decrease leads to infinity energy. We show that in a class of four-dimensional massive gravity theories there exists spherically symmetric solutions with finite total energy, featuring an asymptotic behavior slower than 1/r and generically of the form $r^\gamma$. This suggests that configurations with nonstandard asymptotics may well turn out to be physical. The effect is due to an extra field coupled only gravitationally, which allows for modifications of the static potential generated by matter, while counterbalancing the apparently infinite energy budget.
        Orateur: Dr Luigi Pilo (Department of Physics University of L'aquila)
        Transparents
      • 16:50
        Leptogenesis in neutrinophilic Higgs doublet models 15m
        We show that in a class of two Higgs doublet model, where one Higgs doublet generates masses of quarks and charged leptons whereas the other Higgs doublet with a tiny vacuum expectation value generates neutrino Dirac masses, large Yukawa couplings lead to a large enough CP asymmetry of the right-handed neutrino decay. Thermal leptogenesis suitably works at low energy scale as keeping no enhancement of lepton number violating wash out effects.
        Orateur: Dr Osamu Seto (Hokka-Gakuen University)
        Transparents
      • 17:10
        Loop Quantum Cosmology 15m
        Loop Quantum Gravity is a very attractive attempt to perform a non-perturbative and background-independant quantization of general relativity. Applied to the Universe as a whole, the resulting framework, Loop Quantum Cosmology (LQC) has led to several important results beginning by the fact that the Big Bang singularity is resolved and replaced by a Big Bounce. In this talk, I will focus on showing that LQC naturally leads to inflation and could leave observational features that might be detected by the next generation CMB experiments.
        Orateur: Aurélien Barrau (LPSC)
        Transparents
      • 17:30
        Probing dark energy with the Large Synoptic Survey Telescope (LSST). 15m
        The Large Synoptic Survey Telescope (LSST) system will produce a 6-band wide and deep field astronomical survey of over 20,000 square degrees of the southern sky using an 8.4-meter ground-based telescope. Each patch of sky will be visited about 1000 times in ten years. Its camera will be the world largest one, with 3200 Megapixels. It will cover a huge 9.6 square degree field of view, and will consequently produce an impressive amount of data 30 terabytes per night. Science objectives of the LSST include dark energy, solar system, optical transients and galactic structure. After having presented in details the experiment, I will mainly focus on showing how the nature of dark energy can be investigated by LSST through multiple probes, all using the same survey data. The two most powerful of these are weak gravitational lens tomography and baryon acoustic oscillations (BAO). I will emphasize on BAO and present the expected LSST accuracy on dark energy parameters reconstruction.
        Orateur: Mlle alexia gorecki (LPSC)
        Slides
      • 17:50
        The Dark Energy Survey 15m
        The Dark Energy Survey will employ a powerful instrument, the Dark Energy Camera, and a state-of-the-art data management system on the improved Blanco 4-meter telescope at CTIO to probe the nature of dark energy and the cause of cosmic acceleration. The instrument includes a 520-Megapixel optical imager with red-sensitive CCDs covering a 3 square degree field of view and an active alignment system. Starting in 2012, using 525 nights over 5 years, the survey will image 300 million galaxies over 5000 square degrees to 24th magnitude and several thousand supernovae over a smaller area, using the grizY passbands. The 120-member international collaboration will use these data to probe dark energy using the galaxy cluster abundance, weak gravitational lensing, baryon acoustic oscillations, and supernovae and carry out studies of strong lensing, galaxy evolution, the structure of the Milky Way, and QSOs, among other topics. We will discuss the status of the project, the survey strategy and prospects for cosmological tests.
        Orateur: Ignacio Sevilla (CIEMAT, Madrid)
        Transparents
      • 18:10
        Evidence for a new variability in Type Ia Supernovae from The Nearby Supernovae Factory 15m
        Type Ia supernovae (SNe~Ia) are used as standard candles to measure the history of the universe expansion. However, precise measurements need an empirical standardization of the luminosities usually done with two light-curve derived parameters (stretch and color): brighter SNe~Ia exhibit a broader light curve, and redder objects are fainter. Employing the flux calibrated spectra sample obtained by the Nearby Supernova Factory, we show that there are actually two main components instead of one entering in the object color law, the first related to intrinsic spectral features, and the other related to extrinsic extinction by dust. We then find a value of the total-to-selective extinction ratio $R_V$ in agreement with the standard Milky-Way value, as opposed by the low values found in pure photometric approaches.
        Orateur: nicolas Chotard (Institut de physique nucléaire de Lyon)
        Slides
    • 16:30 18:30
      Detector R & D and Data Handling Lesdiguières

      Lesdiguières

      Alpes Congrès - Alpexpo

      • 16:30
        PANDA detector R&D study 15m
        PANDA is an experiment designed for the future FAIR facility at GSI to challenge our understanding of the strong interact ion and of hadronic matter. Exploiting the high luminosity and good quality of the cooled antiproton beam, PANDA will search for new forms of matter, namely for precise measurements of possible exotic states, such as glueballs, hybrids, pentaquarks etc. in the quark confinement area. One of the major detector components for the study of electromagnetic probes is compact and fast electromagnetic barrel calorimeter constructed out of high quality lead tungstate (PWO) crystals. The most forward region will be covered by a fine-segmented small cell sampling electromagnetic calorimeter as another key detector at PANDA. We report on the R&D study of both PANDA calorimeters including the achieved performance of both PWO and Shashlik calorimeter prototypes. The report includes studies of long-term radiation hardness of PWO crystals at low temperature using infrared-light or temperature for recovery. The PANDA physics program requires the construction of a Silicon Micro Vertex detector with utmost capability to reconstruct primary vertex and secondary vertices from D meson decays. Inhomogeneous distribution of the radiation damage with a strong peak in the forward direction imposes innovative solutions and asymmetric layout. Besides limited material budget and triggerless system, capable to handle large amounts of data in real-time, are requested. For the inner layers of the detector, thinned epitaxial silicon hybrid pixels are under study with custom readout chips, called ToPix. For the outer layers a double-sided silicon strip detector is under development. R&D study of other PANDA detectors is also presented.
        Orateur: Vasily Mochalov (IHEP,Protvino)
        Slides
      • 16:45
        Analyses of test beam data using the CALICE calorimeter 15m
        The CALICE collaboration has developed highly granular calorimeter prototypes to evaluate technologies for experiments at a future lepton collider, and evaluated their performance in test beams. One important use of these data is the validation of the physics models in GEANT4, especially those related to hadronic showers. This validation is crucial if Monte Carlo simulations are to be used to optimise the design of detectors for ILC or CLIC. In this talk we discuss several features of hadronic showers recorded in the CALICE Si-W ECAL and scintillator-tile HCAL. The high spatial resolution of the calorimeters permits the investigation of shower shapes in unprecedented detail. For example, the start point of the shower can be identified with high precision, and the longitudinal development of the shower after this point permits some discrimination between the various components of the shower (nuclear spallation, electromagnetic components, MIP-like hadrons etc.). Detailed substructure within the shower, such as track segments, can also be identified. Many of these features present new challenges to the simulation models. We also report on recent tests of the time-structure of hadronic showers in a tungsten calorimeter - a topic of especial interest for a CLIC detector where accurate time stamping is required. The calorimeters being built and tested by the CALICE collaboration are intended to be optimised for particle flow (PFA) reconstruction of jets at a future linear collider. This places an emphasis on measuring showers with a high spatial granularity, in order that nearby showers can be disentangled. The calorimeters are generally non-compensating, in other words they do not give the same response to photons as charged hadrons. However, the high level of detail recorded within the showers can be exploited in the form of "software compensation". A variety of techniques can be used to discriminate between the different components within showers and hence to weight them differently so as to improve the energy resolution. This approach is also found to improve the linearity of the response. We report on several studies along these lines. The CALICE data on single pion showers can also be exploited to validate the particle flow concept. By superimposing the data from two separate showers, removing the incoming particle track from one of them, we can emulate a neutral hadron shower in the neighbourhood of a charged particle, at various separation. By offering these hybrid events to the standard PandoraPFA algorithm we can evaluate its ability to reconstruct neutral energy in a difficult environment. We show the results of this procedure, in comparison with the Monte Carlo models usually used for the testing of PFA codes.
        Orateur: M. Mikhail Danilov (ITEP-Moscow)
        Slides
      • 17:00
        CALICE Prototype Calorimeters for Linear Collider detectors 15m
        For several years, CALICE has been testing highly granular calorimeter prototypes using analogue readout. These devices are envisaged for particle flow application in a future linear collider detector. A novel alternative, especially interesting for the hadron calorimeter, is to use digital readout, with a very small cell size. In the past year the first large scale (1m³) digital HCAL has been operated by CALICE in test beams at Fermilab. This detector uses glass RPCs for readout within an iron absorber structure. The RPCs are read out through 1x1 cm² pads with a single threshold, providing a digital image of the shower with high spatial resolution. Including a similarly equipped tail catcher, the system contains almost 500,000 readout channels. We report on the technical performance of this calorimeter, and show first physics results on shower reconstruction. A related approach is to use RPCs with two-bit readout, providing three threshold values, referred to as a "semi-digital" HCAL. This approach is being pursued under the aegis of EUDET. Already in 2010 a full 1m² plane was tested in a beam, and a full 1m³ is being tested at CERN in 2011. The current status is reported. In addition, tests in 2010 demonstrated the performance of these RPCs in a 3T magnetic field, and also showed that there was no degradation of performance when the electronics was "power pulsed", a technique which is envisaged to reduce power dissipation in an ILC detector. Alternative technologies for a digital HCAL are also being studied, both Micromegas, for which 1m² planes have already been tested in beams, and GEMs for which 30x30 cm² units are currently being tested. Second generation analogue devices are also under construction, and we report progress here. The focus of this work is to develop technical solutions which could be scaled up to a full-sized detector. The development of a highly segmented electromagnetic calorimeter based on silicon sensors with 5x5 mm² segmentation will be described, covering developments in sensor design, readout electronics and the mechanical and thermal issues of detector integration. The plan is to test one full-length module along with a fully instrumented 18x18 cm² tower. Modules are also being constructed using an alternative technology based on scintillator-strip sensors. The second generation analogue HCAL is based on scintillating tiles that are individually read out by silicon photomultipliers. The prototype will contain about 2500 detector channels, corresponding to one calorimeter layer and aims at demonstrating the feasibility of building a detector with fully integrated front-end electronics.
        Orateur: M. Lei Xia (Argonne)
        Slides
      • 17:15
        Recent results on dual readout in calorimetry from the DREAM Collaboration. 15m
        The energy resolution of the hadronic calorimeters is determined by fluctuations in the development of the shower. In non compensating calorimeters the dominant contribution comes from the fluctuation of the electromagnetic shower fraction. The dual readout technique proposed by DREAM aims to correct event by event for the fluctuations of the e.m. component measuring at the same time scintillation and Cherenkov light. In the last years the DREAM Collaboration has performed several tests to exploit the dual readout technique in calorimeters. Many types of crystals (PbWO, BGO, BSO, etc.) have been exposed in test beams to evaluate the Cherenkov yield and how to optimize the light collection (analysis in time of the signal, filtering of the signals, polarization of the Cherenkov component). The extention of the dual readout to crystal is in fact very important when the hadronic calorimeter follows an electromagnetic calorimeter often composed by crystals. The possibility to use tiles of absorber interleaved with tiles of quartz and scintillator for the dual readout has also been tested. At present the DREAM Collaboration is testing a new copper calorimeter with scintillator and clear PMMA fibers. In the presentation a report will be given on this activity of the DREAM Collaboration.
        Orateur: Dr Francesco Lacava (Dep. Physics University "Sapienza - Roma / INFN - Roma)
        Transparents
      • 17:30
        Design and R&D of very forward calorimeters for detectors at future e+e- collider 15m
        [On behalf of the FCAL Collaboration] Detectors at future e+e- collider need special calorimeters in the very forward region for a fast estimate and precise measurement of the luminosity, to improve the hermeticity and mask the central tracking detectors from back-scattered particles. Using Monte Carlo simulations, designs optimized for the ILC and CLIC colliders are presented. Sensor prototypes have been produced and dedicated FE ASICs have been developed and tested for the ILC. For the first time, a prototype of sensor planes has been assembled and tested in a particle beam. Results on the performance will be given.
        Orateur: Dr Ivanka Bozovic-Jelisavcic (VINCA Institute of Nuclear Sciences)
        Transparents
      • 17:45
        The Muon ATLAS MicroMegas Activity 15m
        The luminosity upgrade of the Large Hadron Collider at CERN (sLHC) foresees a luminosity increase by a factor five compared to the LHC. To cope with the corresponding increase in background rates, the Muon System of the ATLAS experiment at CERN will likely need major changes in the very forward/backward regions. The Muon ATLAS MicroMegas Activity (MAMMA) is focused on the development and testing of large-area muon detectors based on the bulk-Micromegas technology as candidates for such an upgrade. In order to overcome the spark problem a novel protection scheme using resistive strips above the readout electrode has been developed. This technology has undergone extensive tests with hadron beams at the CERN-SPS, X-rays in the lab, as well as tests in a neutron beam at the TANDEM accelerator of the N.C.S.R. “Demokritos’. In addition a set of prototype chambers have been installed in the ATLAS cavern and are taking data in real LHC conditions. Results on the performance of these chambers will be presented.
        Orateur: Georgios Tsipolitis (National Technical University of Athens)
        Transparents
      • 18:00
        Performance studies of large-area triple-GEM prototypes for future upgrades of the CMS forward muon system 15m
        The RPC muon system of the CMS detector at the CERN LHC remains uninstrumented in the pseudorapidity region 1.6<|eta|<2.4. An ongoing project aims at covering the region of the muon endcaps with large-area triple- GEM detectors whose features are suited to enhance muon tracking and preserve triggering capabilities for the CMS detector upgrade. The design and assembling of small (10cm×10cm) and full-size trapezoidal (1m×0.5m) triple-GEM prototypes will be described. The prototypes have been tested with soft x-rays and with a pion/muon test beam at the CERN SPS. Results from measurements with different experimental set-up on detector resolution and efficiency as well as timing performance will be reported. Preliminary simulation results will be discussed, related to studies on performance variations of the expected muon tracks reconstruction and trigger performance for different upgraded muon system scenarios with several physics processes. Micro-Pattern Gas Detectors (MPGDs) are the detector technology of choice for simultaneously providing precision tracking and fast trigger information. They can be designed with sufficiently fine segmentation to cope with the hostile environment at a high-luminosity LHC and are being considered for a CMS high-eta muon upgrade. Several Triple Gas Electron Multiplier (GEM) prototypes have been built for this project with conventional construction techniques over the last two years. Here we report on a novel design and construction technique for a small Triple-GEM detector prototype. This method uses a purely mechanical way to stretch GEM foils in situ and does not require spacer frames or gluing, making it potentially very interesting for large-scale, cost-effective industrial production of GEM detectors. We will present details of the detector assembly procedure and results of preliminary performance tests of the resulting detector prototype.
        Orateur: M. Salvatore Alessandro Tupputi (Politecnico di Bari and INFN Sezione di Bari)
        Slides
      • 18:15
        Detector Requirements and R&D Challenges at CLIC 15m
        The expected results from the LHC experiments will give us an idea of the physics at the TeV scale. A lepton-collider at these energies will then be required to complement the information from the LHC, and to fully understand the physics. The Compact Linear Collider (CLIC) with a center of mas energy of up to 3 TeV is a suitable concept for such a future e^{+}-e^{-}-linear-collider. The detector requirements for precision measurements at multi-TeV-energies in general and the special experimental conditions at the CLIC accelerator open a rich field of detector R&D opportunities. These requirements go beyond those for a detector at the ILC. Nevertheless, the R&D work that is being performed for the ILC detectors is an excellent starting point for these studies. The specific challenges are for example the use of dense calorimeter absorber materials for excellent jet energy resolutions up to the highest energies and low material silicon detectors with small pixel sizes. In addition, the high machine-induced-background levels in combination with the short time of only 0.5 ns between two bunch crossings at CLIC will require time-stamping capabilities throughout all sub-detectors. Preliminary results from the studies for the CLIC conceptual design report and ongoing R&D projects will be presented.
        Orateur: Christian Grefe (CERN)
        Slides
    • 16:30 18:30
      Flavour Physics and Fundamental Symmetries les Ecrins 3

      les Ecrins 3

      Alpes Congrès - Alpexpo

      • 16:30
        Lattice Flavour Physics 20m
        I will review state of the art lattice calculations of hadronic matrix elements that play a role in flavour physics (decay constants, bag parameters, form factors parametrizing semileptonic decays) both for light and heavy flavoured mesons. I will also briefly discuss how the present accuracy on some of these quantities can eventually be improved by considering effects that have been neglected up to now (long distance, isospin breaking, etc.).
        Orateur: Dr Nazario Tantalo (University of Rome "Tor Vergata")
        Transparents
      • 16:50
        The complete charm-quark contribution to epsilon_K and Delta M_K 15m
        Neutral Kaon mixing plays an important role in the phenomenology of the standard model and its extensions because of its sensitivity to high-energy scales. In this talk I will give a summary of the theory prediction of epsilon_K and Delta M_K and present our new NNLO QCD calculation of the charm-quark contribution eta_cc to the Delta S = 2 effective Hamiltonian.
        Orateur: Dr Joachim Brod (Excellence Cluster Universe, TU Munich)
        Transparents
      • 17:05
        Kaon programme at CERN: recent results and future plans. 15m
        The results from the CERN kaon experiments are presented. A precision test of lepton universality by measurement of the helicity suppressed ratio of kaon leptonic decay rates BR(K --> e nu)/BR(K --> mu nu) has been performed with over 10^5 K+- --> e+- nu decays collected by the NA62 experiment in 2007-08. A record accuracy of 0.4% has been achieved, which constrains the parameter space of new physics models with extended Higgs sector. An improved upper limit on the rate of the lepton number violating decay K+- --> pi-+ mu+- mu+-, which is sensitive to the existence of Majorana neutrinos, has been established with a K+- sample collected by the NA48/2 experiment in 2003-04. A new precise measurement of the K+- --> pi0 mu+- nu (Kmu3) decay form factors with more than 3 million events collected by NA48/2 with a minimum trigger setup is presented, which is an indispensable input for the determination of the CKM matrix element |Vus| from semileptonic kaon decays. Finally, the status of a future experiment aiming to measure the rate of the ultra-rare flavour changing neutral current decay K+ --> pi+ nu nubar to a record 10% precision with a low background sample of about 100 decays is discussed.
        Orateur: Dr Evgueni Goudzovski (University of Birmingham)
        Slides
      • 17:20
        Kaon Physics at KLOE and KLOE-2 prospects 15m
        A phi-factory offers the possibility to select pure kaon beams: neutral kaons from phi → KSKL are in fact produced in pairs and the detection of a KS (KL) tags the presence of a KL (KS), the same holds for charged kaons. This allows to perform precise measurement of kaon properties. The KLOE experiment has measured most decay branching ratios of K_S, K_L amd K^+- mesons providing the basis for the determination of the CKM parameter V_us and the most precise test of the unitary of the quark flavor mixing matrix. We are presently finalizing new determinations of BR(K+- -> 3 charged pions), to complete the KLOE program of precise and fully inclusive measurements of the kaon dominant BR's, and finalizing the update of the upper limit on the branching ratio measurement of the CP-violating transition Ks -> 3pi0 (Phys. Lett. B619, 61,2005), using the complete data set. The neutral kaon system also offers unique possibilities to perform fundamental tests of CPT invariance, as well as of the basic principles of quantum mechanics. In particular a new analysis of the KLOE data is aiming at the measurement of the parameters describing the CPT and Lorentz symmetries breaking in the framework of the Standard-Model Extension (SME), and exploiting the EPR correlations in the neutral kaon pairs produced at DAPHNE. Prospects on further improvements at the KLOE-2 experiment, aiming at an integrated luminosity of about 20 fb-1 with an upgraded detector, will be also discussed.
        Orateurs: Mme Caterina Bloise , Collaboration KLOE-2 (LNF-INFN)
        Slides
      • 17:35
        Flavor Physics in an SO(10) Grand Unified Model 15m
        In a supersymmetric grand-unified model proposed by Chang, Masiero and Murayama the atmospheric neutrino mixing angle induces large new b --> s transitions. Relating the supersymmetric low-energy parameters to seven new parameters a_0, m_0^2, m_{\tilde g}, D, xi, tan(beta) and arg(mu) of this SO(10) GUT model, we perform a correlated study of several FCNC processes. The LEP limit on the lightest Higgs boson mass implies an important lower bound on tan(beta), which in turn limits the size of the new FCNC transitions. Remarkably, the combined analysis does not rule out large effects in B_s-\bar{B_s} mixing and we can easily accommodate the large CP phase in the B_s-\bar{B_s} system which has recently been inferred from a global analysis of CDF and D0 data. The model predicts a particle spectrum which is different from the popular CMSSM. BR(tau --> mu gamma) enforces heavy masses, typically above 1 TeV, for the sfermions of the degenerate first two generations. However, the ratio of the third-generation and first-generation sfermion masses is smaller than in the CMSSM and a (dominantly right-handed) stop with mass below 500 GeV is possible.
        Orateur: Dr Jennifer Girrbach (TU Munich)
        Transparents
      • 17:50
        Global fit to CKM data 15m
        We present updated results for the CKM matrix elements from a global fit to Flavour Physics data within the Standard Model theoretical context. We describe some current discrepancies, established or advocated, between the available observables. These discrepancies are further examined in the light of New Physics scenarii.
        Orateur: M. Valentin Niess (LPC, Clermont)
        Slides
      • 18:05
        Standard Model updates and new physics analysis with the Unitarity Triangle fit, 15m
        We present the summer 2011 update of the Unitarity Triangle (UT) analysis performed by the UTfit Collaboration within the Standard Model (SM) and beyond. Within the SM, combining the direct measurements on sides and angles, the UT is over-constrained allowing for the most accurate SM predictions and for investigation on the tensions due to the most recent updates from experiments and theory. Generalizing the UT analysis to investigate NP effects, constraints on b -> s transitions are also included and both CKM and NP parameters are fitted simultaneously. The inputs to this analysis include the updated Tevatron analyses on B_s-\bar B_s mixing that are significantly improving the NP constraints on the previously unexplored B_s sector. Finally, based on the NP analysis, we derive upper bounds on the coefficients of the most general Delta F=2 effective Hamiltonian. These upper bounds can be translated into lower bounds on the scale of new physics that contributes to these low-energy effective interactions.
        Orateur: Dr Marcella Bona (Queen Mary, University of London)
        Transparents
    • 16:30 18:30
      Higgs and New Physics Dauphine

      Dauphine

      Alpes Congrès - Alpexpo

      • 16:30
        Higgs bosons in the Next-to-Minimal Supersymmetric Standard Model 15m
        We review possible properties of Higgs bosons which are specific to the NMSSM as light CP-even scalars consistent with LEP bounds, decays into a pair of light CP-odd scalars, and enhanced branching ratios into two photons. The status of analyses to detect such unconventionally decaying Higgs bosons is descussed.
        Orateur: Ulrich Ellwanger (LPT Orsay)
        Transparents
      • 16:45
        Searches for Light New Physics with BABAR 15m
        We present the results of direct searches for light new physics with BABAR. In particular, we describe studies of narrow Upsilon and B decays with sensitivity to possible light pseudoscalar Higgs bosons and invisibly decaying dark matter candidates. We also present results of searches for hidden sector gauge and Higgs bosons.
        Orateur: Alberto Lusiani
        Slides
      • 17:00
        Search for a CP-odd light Higgs in $\Upsilon(1S)$ radiative decays at Belle 15m
        We search for a CP-odd light Higgs among 102 M $\Upsilon(1S)$ events recorded with the Belle detector at KEKB. Our signal mode is $\Upsilon(1S)\to\gamma A_0;A_0\to \tau^+\tau^-$, where the $\tau$ is detected via its leptonic decay modes. We determine the upper limits on the production rates for a CP-odd light Higgs with a mass between the $\tau^+\tau^-$ threshold and 9.4 GeV/$c^2$. This result puts stringent constraints on theoretical models of low mass NMSSM Higgs bosons.
        Orateur: Jamal Rorie
        Slides
      • 17:15
        SUSY Searches 30m
        SUSY Searches
        Orateur: Michele Papucci
        Slides
      • 17:45
        SUSY searches at the Tevatron 15m
        We present the result of various searches for the production of supersymmetric particles in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using data collected by the CDF and D0 detectors at the Fermilab Tevatron Collider and corresponding to integrated luminosities of up to 6 fb$^{-1}$. We present results for the searches for the pair production of stop squark and searches for the associated production of charginos and neutralinos in final states with $\tau$ leptons. We also present the results for the search for pairs of isolated jets of leptons, predicted in hidden valley models. The results of these searches are interpreted in various frameworks of physics beyond the Standard Model.
        Orateur: Eric KAJFASZ (CPPM)
        Slides
      • 18:00
        Searches for GMSB SUSY in diphoton plus missing transverse energy and photon plus Z plus missing transverse energy at Tevatron 15m
        We report the result of searches for final states with 2 vector bosons, either two photons or one photon plus one $Z$, in association with large missing transverse energy produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV. The data were collected with the D0 detector at the Fermilab Tevatron Collider and correspond to up to 6.3 fb$^{-1}$ of integrated luminosity. The observed missing transverse energy distributions are used to set limits on different realizations of theories beyond the standard model, including limits on the breaking scale $\Lambda$ of gauge mediated supersymmetry models.
        Orateur: Prof. Mark Adams (University of Illinois at Chicago)
        Slides
      • 18:15
        Global SUSY Fits with the MasterCode Framework 15m
        We present the latest results of the MasterCode collaboration on global SUSY fits. Currently available experimental data are used to determine the preferred SUSY and Higgs boson mass scales. The data comprise a combination of high-energy SUSY searches, low-energy precision measurements and astrophysical data. We include all relevant LHC searches for SUSY, electroweak precision observables such as the W boson mass and the anomalous magnetic moment of the muon, B physics observables such as BR(b -> s gamma), as well as the cold dark matter density in the Universe. The preferred masses for SUSY particles as well as for the MSSM Higgs bosons are derived in the context of four GUT-based realizations of the MSSM. We find a preference for relatively light SUSY masses, which the direct searches at the LHC shift to slightly higher mass scales. The preferred mass values can directly be compared to the reach of the the LHC and future e+e- colliders as well as to current and future direct detection searches for dark matter. MasterCode Collaboration: O. Buchmueller , R. Cavanaugh, A. De Roeck, M.J. Dolan, J.R. Ellis, H. Flacher, S. Heinemeyer, G. Isidori, K. Olive, S. Rogerson, F. Ronga, G. Weiglein
        Orateurs: MasterCode Collaboration (MasterCode) , Samuel Rogerson (Imperial College London)
        Slides
    • 16:30 18:30
      Neutrino Physics Oisans

      Oisans

      Alpes Congrès - Alpexpo

      • 16:30
        New Results from the MINOS Experiment 20m
        MINOS is a long baseline neutrino oscillation experiment which utilises the NuMI muon neutrino beam from Fermilab. MINOS has two detectors, a Near Detector 1km from the beam source, and a Far Detector 735km away in the Soudan mine in Minnesota. New results from MINOS will be presented and discussed.
        Orateur: Dr Anna M Holin (University College London)
        Transparents
      • 16:50
        New results from the T2K experiment 30m
        The T2K (Tokai to Kamioka) experiment is a long baseline neutrino oscillation experiment designed to probe the θ13 neutrino mixing parameter by looking for the appearance of νe in an almost pure νμ beam. The concurrent measurement of νμ disappearance allows refined measurements of the atmospheric Δm2 and of the θ23 mixing parameters. A neutrino beam is produced at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai, Japan, and aimed at 2.5° off the direction of the Super-Kamiokande (Super-K) detector, 295 km away. The resulting narrow energy band neutrino beam at the Super-K location, peaked at about 600 MeV, is optimized to maximize the probability of oscillation at the atmospheric Δm2 scale, minimizing at the same time the background for νe searches. The neutrino beam is monitored by an on-axis non-magnetic detector, INGRID, and an off-axis magnetic near detector, ND280, both located at J-PARC at 280 m from the target. In addition, the primary proton beam and the muons from the secondary pion decays in the neutrino beam-line are monitored on a spill by spill basis to