50th Rencontres de Moriond EW 2015

14 mars 2015, 08:30 → 21 mars 2015, 12:00 Europe/Paris

Jean Marie Frere (ULB Brussels), Lydia Iconomidou-Fayard (LAL)

The 50th Rencontres de Moriond session devoted to ELECTROWEAK INTERACTIONS AND UNIFIED THEORIES will be held in La Thuile from Saturday March 14th to Saturday March 21th, 2015.

La Thuile is a pleasant winter sport resort located in the Italian Alps, at 1450 m alt., about 120 km from Geneva. The nearest international airport is Geneva (Switzerland).

Since its foundation in 1966 by Jean Tran Thanh Van, the Rencontres de Moriond bring together theorists and experimentalists for in-depth discussions on recent findings and new ideas in elementary particle physics in a pleasant, relaxed and intimate atmosphere.

The meeting is intended to promote fruitful collaboration between experimentalists and theorists and between various institutions by bringing together a limited number of physicists and astrophysicists in beautiful and inspiring surroundings.

This session is devoted to electroweak interactions and to unified theories.
The Rencontres de Moriond are sponsored by

• CNRS, IN2P3, CEA/IRFU (France)
• FNRS, Belgian Science Policy (Belgique)
• NSF (USA)

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Program Programme2015v0.9-3_p.pdf

dimanche 15 mars

08:30 → 12:00 Neutrino Physics: Morning session

08:30 Status of three-neutrino mixing

The status of known and unknown three-neutrino parameters will be briefly reviewed, providing an introduction to subsequent talks in the neutrino session.

Orateur: Dr Eligio Lisi (INFN, Bari, Italy)

Slides 1_Lisi_Moriond_2015.pdf

08:55 Recent results from Borexino

Borexino is a large volume liquid scintillator detector mainly devoted to the study of solar neutrinos. It is located under the Gran Sasso mountain in Italy and has been taking data since 2007. Thanks to its low background and its large mass, Borexino has been able of performing an almost complete spectroscopy of solar neutrinos. In this talk I will focus on the latest result published by Borexino, namely the first direct observation of pp-neutrinos. These neutrinos represent the vast majority (~90%) of neutrinos emitted by the Sun, but had so far eluded real-time detection, due to their low energy. The observation of pp-neutrinos provides us with a direct glimpse at the keystone fusion process that keeps the Sun shining. Although the experimental uncertainty (11%) does not allow to distinguish between different solar model hypothesis (high or low metallicity), this measurement strongly confirms our understanding of the Sun.

Orateur: Dr Barbara Caccianiga (INFN, Sezione di Milano)

Paper Caccianiga.tar.gz

Slides Moriond_2015_Borexino.pptx Moriond_2015_pdf_format.pdf

09:15 Entering the Two-Detector Phase of the Double Chooz Experiment

In 2011, Double Chooz became the first reactor-based experiment to indicate a nonzero value of the neutrino mixing parameter $\theta_{13}$. This observation was made with a single detector located approximately 1 km from the two cores of the Chooz Nuclear Power Plant in northeastern France. Since then, the Double Chooz collaboration has increased the precision of its single-detector $\theta_{13}$ measurements through a variety of novel techniques. Now, as the newly commissioned near detector takes its first data, we can begin to suppress the reactor flux uncertainty which dominated previous analyses. We will report the most recent Double Chooz results, projected future precision for $\theta_{13}$, and prospects for additional physics measurements.

Orateur: Rachel Carr (Columbia University)

Paper Carr.pdf

Slides Moriond.pdf

09:40 Recent Results from Daya Bay Reactor Neutrino Experiment

The Daya Bay reactor neutrino experiment announced the discovery of a non-zero value of $\sin^22\theta_{13}$ with significance better than 5 $\sigma$, in 2012. The experiment is continuing to improve the precision of $\sin^22\theta_{13}$ and explore other physics topics. In this talk, I will show the current oscillation and mass-squared difference results which is base on the combination of the rate and energy spectra analysis, an independent measurement of $\theta_{13}$ using the delayed neutron captured by hydrogen signal, and a search on light sterile neutrino mixing.

Orateur: BEI-ZHEN HU (Department of Physics, National Taiwan University)

Paper Hu.pdf

Slides 4_Moriond_DayaBay_BeiZhenHu.pdf

10:00 break

10:25 Recent results from SuperK

I will summarize the most recent nucleon decay and sterile neutrino results from Super-Kamiokande (SuperK) experiment.

Orateur: Dr Shunichi Mine (University of California, Irvine)

Paper MINE.tar.gz

Slides mine_moriond2015_sk_v6.pdf

10:45 Systematic Uncertainties in Reactor Antineutrino Fluxes and Anomaly

In this talk I will discuss the origin of the reactor neutrino anomaly, the physics issues involved, and the uncertainties. Since the suggestion of an anomaly, a second puzzle has arisen with the reactor antineutrino spectra, namely the appearance of a shoulder in the spectra measured at Daya Bay, RENO, and Double Chooz. The shoulder is predicted within some nuclear database analyses, but these nuclear databases lack the accuracy to make definitive predictions. Thus, there is a clear need for new short baseline reactor neutrino experiments. I will examine the expected signals from these different experiments and the effect of differences in the hardness of the neutron spectrum on the expected shape of the antineutrino flux.

Orateur: Dr Anna Hayes (Los Alamos National Lab)

Paper hayes-moriond.tar

Slides 6_HAYES-Moriond.pdf

11:10 Selected results from T2K

The T2K ("Tokai to Kamioka") experiment is a long-baseline neutrino oscillation experiment in Japan. A beam of muon neutrinos or muon anti-neutrinos is produced at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai. The unoscillated neutrino flux is measured by the near detector complex 280 m from the proton target, and the oscillated neutrino flux is measured by the far detector, Super-Kamiokande, 295 km away. This talk will review the major T2K neutrino oscillation results to date (from neutrino beam run periods), and provide a first look at the recent anti-neutrino beam run periods.

Orateur: M. Jordan Myslik (University of Victoria)

Paper JordanMyslik.pdf JORDANMYSLIK.tar.gz

Slides 2015_MoriondEW_T2K_myslik_v5.pdf

17:00 → 20:40 Neutrino Physics: Afternoon session

17:00 3-Loop Neutrino Mass Models and Phenomenology

We consider classes of standard model (SM) extensions with a scalar representation (charged singlets, triplet and/or 5-plet) and three generation fermionic representations (right handed neutrinos, triplets or 5-plets). In these models, the neutrino masses are generated at three loops, which provide an explanation for their smallness, and the lightest neutral fermion, is a dark matter candidate. We find that for three generation fermionic representations, the model can be consistent with the neutrino oscillation data, lepton flavor violating processes, give a relic density in agreement with the recent Planck data, and the electroweak phase transition can be strongly first order. We also show that the charged scalars may enhance the branching ratio $h−−>\gamma\gamma$, where as $h−−>\gamma Z$ get can get few percent modification. We also discuss the phenomenological implications of the extra particles at both LHC and future electron-positron colliders.

Orateur: Dr Amine Ahriche (U. Jijel)

Slides 1_Moriond-2015-Ahriche.pdf

17:20 Recent results from KamLAND‐Zen

KamLAND-Zen searches for neutrinoless double beta decay with Xe-136 loaded liquid scintillator. After purification of Xe and liquid scintillator, we started 2nd phase of the experiment on December, 2013. We report latest result and future prospects of KamLAND-Zen.

Orateur: Dr Azusa GANDO (Research Center for Neutrino Science, Tohoku University)

Slides 2_KamLAND-Zen_AzusaGando_Moriond2015_s.pdf

17:40 cosmo constraints on seesaw scale

I will study the simplest extension of the SM that can account for neutrino masses: the Type-I seesaw with 2 and 3 right-handed neutrinos. The model introduces a New Physics scale, M, which is often assumed to be much larger than the electroweak scale. However, it is presently unconstrained and the light neutrino masses and mixing can be generated for any value of M above eV. Paying special attention to the contribution of the sterile states to $N_{eff}$ as a function of M, I will show that a large part of the M parameter space can be excluded thanks to cosmological measurements. The implications for neutrinoless double beta decay will also be discussed.

Orateur: Dr Jacobo Lopez Pavon (SISSA)

Paper proceedingJLP.tar.gz

Slides 3_Lopez-Pavon-CosmoconstraintSeesaw.pdf

18:00 Prospects to determine the neutrino mass hierarchy

Discovery of the third mixing angle theta13 has opened up the possibility of discovering the neutrino mass hierarchy. There are a number of near future experiments proposed (some already funded) which aim at determining the mass hierarchy. In this talk I will review the prospects of discovering the neutrino mass hierarchy in the next generation neutrino experiments.

Orateur: Dr Sandhya Choubey (Harish-Chandra Research Institute)

Paper choubey.tar.gz

Slides 4_Choubey_moriond2015_s.pdf

18:20 Searches for Beyond the Standard Model Physics in Double Beta Decay with EXO-200

EXO-200 is an experiment searching for neutrinoless double beta decay using a time projection chamber with 175 kg of liquid xenon enriched in $^{136}$Xe. The observation of this process would indicate that the neutrino is a Majorana fermion and lepton number is not a conserved quantity, and would allow for the calculation of the absolute mass of the neutrino. The low radioactive background and high sensitivity of the experiment also provide a venue to search for other theoretical exotic processes. Majoron modes of double beta decay are processes that would occur if the neutrino is a Majorana fermion and a scalar boson is created in the neutrino self interaction, resulting in an electron sum spectral shape that deviates from the standard two-neutrino double beta decay spectrum. The latest analysis techniques and results of searches for neutrinoless double beta decay and other exotic processes in EXO-200 will be presented.

Orateur: Mlle Tessa Johnson (Indiana University)

Paper Johnson.pdf

Slides 5_Moriond_Talk_TessaJohnson_Final.pdf

18:40 break

19:05 Neutrinoless double beta decay and nuclear matrix elements

Confirmation of neutrino oscillations in different experiments has established the massive character of neutrino and served as a strong evidence to look beyond the well-accepted standard model of particles. Most of the unified theories thus evolved are based on Majorana character of neutrinos. At present most promising and only experiment to settle the Majorana/Dirac nature of neutrino that is being pursued by different groups is the search for neutrinoless double beta decay. Apart from establishing Majorana character of neutrinos this experiment is also the most sensitive way to look for the neutrino mass. However, in the process of extraction of neutrino mass the nuclear transition matrix elements of nuclei involved in specific experiment and different theoretical models and approaches used for extraction of these matrix elements play crucial role in arriving at the the value of neutrino mass from neutrinoless double beta decay. Status of nuclear matrix elements calculations in general will be discussed and the connected uncertainties in particular shall also be reported.

Orateur: Prof. Prabhu K Raina (IIT Ropar, india)

Paper Raina.pdf

Slides 6_RAINA_15_march15.pdf

19:25 Lepton Number Violation with and without Majorana Neutrinos

We discuss the various incarnations of a gauged B-L symmetry: 1) as an unbroken symmetry, it features Dirac neutrinos, neutrinogenesis to create the baryon asymmetry, and a potentially light Z' boson; 2) broken by two units, we obtain the standard case of Majorana neutrinos, seesaw and thermal leptogenesis; 3) broken by four units, we find Dirac neutrinos with lepton-number-violating interactions, which can give rise to a new Dirac leptogenesis mechanism. We review and discuss the signatures distinguishing the three scenarios.

Orateur: Dr Julian Heeck (Université Libre de Bruxelles)

Paper heeck.pdf

Slides 7_heeck-neutrinos.pdf

19:45 NA61/SHINE Data for Long Baseline Neutrino Experiments

The NA61/SHINE experiment at the CERN SPS has a rich physics pro- gramme. Beside the ion and the cosmic ray programmes, hadron production measurements are conducted for precise prediction of conventional accelera- tor neutrino beams. The neutrino physics program started with a dedicated hadron production campaign for the T2K experiment. The success of this data taking has proven the important role that NA61/SHINE plays as an an- cillary experiment for present and future long baseline neutrino programmes. A new campaign for hadron production measurements for Fermilab neutrino beams has already started. In this brief report, we give an overview of the NA61/SHINE experiment capabilities and the dierent analysis methods de- veloped for the neutrino ux prediction. An overview of the current results for the T2K experiment will be shown and future plans will be presented. Examples of the implementation of the hadron production measurements for the precise T2K neutrino ux prediction will be discussed.

Orateur: Alexis Haesler (Unige)

Slides 8_haesler_2015_Moriond.pdf

20:05 Recent results from MINERvA

Fermilab's MINERvA experiment is designed to make precision measurements of neutrino scattering cross sections on a variety of materials. After introducing the MINERvA detector, I will explain why these measurements are so important to the current neutrino program. I will then describe several recently published results that are already being applied by the neutrino community to improve their modeling of neutrino interactions. There will also be a chance to look at interesting analyses that will be published in the coming months, and at the plans for MINERvA's longer-term future.

Orateur: Mlle Cheryl Patrick (Northwestern University)

Transparents Moriond_2015_CPatrick_Minerva.pdf

lundi 16 mars

08:30 → 12:00 VHE and Dark Matter: Morning session

08:30 Indirect searches for sterile neutrinos at a high-luminosity Z-factory

A future high-luminosity Z-factory will offer the possibility to study rare Z decays, as those leading to lepton flavour violating final states. Processes such as Z → l∓1 l±2 are potentially complementary to low-energy (high-intensity) observables of lepton flavour violation. We address the impact of new sterile fermions on lepton flavour violating Z decays, focusing on potential searches at FCC-ee (TLEP), and taking into account experimental and observational constraints on the sterile states. We consider a minimal extension of the Standard Model by one sterile fermion state, and one well-motivated framework of neutrino mass generation, the Inverse Seesaw embedded into the Standard Model. The results show that sterile neutrinos can give rise to contributions to BR(Z → l∓1 l±2 ) within reach of the FCC-ee. We also discuss the complementarity between a high-luminosity Z-factory and low-energy charged lepton flavour violation facilities.

Orateur: Dr Valentina De Romeri (CNRS)

Paper De_Romeri.tar.gz

Slides 1-De_Romeri_s.pdf

08:50 Latest results from IceCube on astrophysical neutrinos and neutrino oscillations

The IceCube Neutrino Observatory is a cubic kilometer ice Cherenkov neutrino detector, located at the geographic South Pole, detecting neutrinos starting at energies of about 10 GeV. In the last couple of years IceCube has established the existence of a high-energy astrophysical neutrino flux in the 100 TeV - PeV range at the level of $10^{-8}$ GeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$ per flavor with high significance. DeepCore, a region of denser instrumentation at the lower center of the detector, detects low-energy atmospheric neutrinos (< 100 GeV), which are used to study the phenomenon of neutrino oscillations with a precision comparable to that of the leading experiments in the field. The latest results on both of these topics are discussed.

Orateur: M. Juan Pablo Yanez (DESY)

Paper yanez_moriondEW15.tar.gz

Slides 2_Yanez_Moriond_2015_v5_s.pdf

09:15 The Flavour Composition of High Energy Neutrinos in IceCube

The recent detection of 37 high-energy neutrinos of astrophysical by the IceCube experiment at the South Pole has signalled the beginning of high-energy neutrino astronomy. At these energies, neutrinos are expected to be produced by pion disintegration after production in high-energy sources. This should lead to a democratic flavour composition at Earth of (1:1:1) electron : muon : tau neutrinos. We present our analysis of the observed flavour composition of the IceCube events, based on the event topology and energy spectra, with a critical eye on the canonical (1:1:1). We demonstrate that current observations hint at some compelling puzzles, notably the lack of lower-energy muon neutrinos, as well as an absence of observed events in the expected Glashow resonance peak above 3 PeV.

Orateur: Dr Aaron Vincent (IPPP Durham)

Paper aaronvincent.tar.gz

Slides 3_AaronVincent_IceCube_s.pdf

09:35 A new physics interpretation of the IceCube data

IceCube has recently published the observation of 37 events of TeV-PeV energies. It is apparent that their angular distribution, spectrum and muon to shower ratio can not be explained assuming standard interactions of atmospheric neutrinos. We obtain an excellent fit, however, if a diffuse flux of ultrahigh energy (cosmogenic) neutrinos experiences collisions where only a small fraction of the energy is transferred to the target nucleon. We show that consistent models of TeV gravity provide cross sections with these precise features. An increased statistics could clearly distinguish our interpretation from the one assumed by IceCube (a diffuse flux of astrophysical neutrinos with a $\propto E^{-2}$ spectrum).

Orateur: Dr Manuel Masip (Universidad de Granada)

Paper masip.tar.gz

Slides 4_Masip.pdf

09:55 break

10:20 Recent results from XENON100

The XENON100 experiment, located at the Laboratori Nazionali del Gran Sasso (LNGS), reached sensitivities on the WIMP-nucleon spin-independent cross section down to 2×10 −47 cm 2 after two years of data taking, excluding the signal at 90 % C.L. Other analysis, in different theoretical framework, have been also published. The next generation experiment, XENON1T, is currently in the commissioning phase and by the fall the start of data taking is expected. In this talk a comprehensive summary of recent results from XENON100 will be shown together with the update on the status of XENON1T project.

Orateur: Dr Gianmarco Bruno (Muenster University)

Paper BRUNO.tar.gz

Slides 5_G_Bruno_moriond_v3.pdf

10:40 Dark matter searches, Run1 results and Run2 potential

Despite the recent discovery of the Higgs boson contributing to the success of the Standard Model, the large excess of Dark Matter in the universe remains one of the outstanding questions in science. This excess cannot be explained by Standard Model particles; a compelling hypothesis is that Dark Matter is comprised of particles can be produced at the LHC, called Weakly Interacting Massive Particles (WIMPs). This talk presents a number of ATLAS and CMS searches for WIMP Dark Matter, outlining the main theoretical benchmarks and issues in terms of complementarity with Direct and Indirect Detection experiments, and describes the studies on Dark Matter searches for the upcoming LHC run.

Orateur: Mlle Caterina Doglioni (University of Oxford)

Paper Doglioni.tar.gz

Slides 6_20150316_MoriondEW_DarkMatterATLASCMS_s.pdf

11:05 Dark matter at the LHC

We discuss recent theoretical advances in the understanding and description of mono-X signals at the lHC.

Orateur: uli haisch (oxford)

Slides 7_Haisch-moriondEW15_s.pdf

11:25 3.55 KeV line in minimal decaying DM

We discuss the possibility of reproducing the recently reported 3:55 KeV line in some simple decaying dark matter scenarios. The decaying Dark Matter is coupled to the Standard Model(SM) through a scalar field charged under the SM group which can pair produced at the LHC. The DM density is generated through freeze-in by the decay of the scalar field. The combined constraints from DM Inderect Detection and relic density allow to infer the detection prospects at the LHC of the scalar field.

Orateur: Dr Giorgio Arcadi (LPT Orsay)

Paper proceedings_moriond_arcadi.tar.gz

Slides 8_moriond_arcadi.pdf

17:00 → 19:30 VHE and Dark Matter: Afternoon session

17:00 Direct dark matter search with the CRESST experiment

The quest for the particle nature of Dark Matter is one of the big open questions of modern physics. The CRESST II experiment located at the Gran Sasso laboratory in Italy is optimised for the detection of the elastic scattering of Dark Matter particles with ordinary matter. We present the result obtained with an improved detector setup with increased radio purity and enhanced background rejection. The limit obtained in the so-called low mass region between one and three GeV/c2 is at the present among the best limits obtained for direct Dark Matter experiments. In addition we give an outlook of the future potential for direct Dark Matter detection using further improved CRESST CaWO4 cryogenic detectors.

Orateur: Jochen Schieck (Institute of High Energy Physics)

Paper MoriondEW_JSchieck.tar

Slides 1_Moriond_CRESST_Schieck_s.pdf

17:20 Recent results from DarkSide

DarkSide-50 is dual-phase liquid argon time projection chamber, designed for direct WIMP search. The detector, consisting of 50 kg of liquid argon and shielded by active neutron and muon vetoes, is installed at Gran Sasso underground laboratory. DarkSide-50 is taking data since November 2013, collecting more than 10^7 events with atmospheric argon, naturally contaminated with cosmogenic 39Ar beta decay. This contamination is equivalent to ~20 years of data taking with underground argon, depleted in 39Ar by a factor larger than 150. Thanks to the excellent nuclear-electron recoil discrimination power of liquid argon and to the high efficiencies of the vetoes, no event has been observed in the WIMP region of interest in 47.1 days of data taking. We present the detector design and performance and the results from the atmospheric argon run.

Orateur: Dr Davide Franco (APC)

Slides 2_franco_moriond2015_corr.pdf

17:40 Sterile neutrino limits from cosmo

Light sterile neutrinos (eV scale), suggested by different anomalies observed in short-baseline neutrino oscillation experiments, can be produced in the early universe by oscillations with the active neutrinos and can affect different cosmological observables: Big Bang Nucleosynthesis (BBN), Cosmic Microwave Background (CMB) and Structure Formation (LSS). Indeed, if the sterile neutrinos are sufficiently light, they can increase the radiation content of the universe (parametrized in terms of the effective number of relativistic degrees of freedom Neff) . Moreover they contribute to the matter density at later time leaving a peculiar imprint on structure formation. We will discuss the mass and radiation limits on eV sterile neutrinos coming from the cosmological observations, also in relation to the recent data of Planck collaboration.

Orateur: Dr Ninetta Saviano (IPPP, Durham University)

Slides 3_moriond_saviano_s.pdf

18:00 The neutrino background to direct detection of dark matter

Dark matter detectors are rapidly improving in sensitivity, and as they continue to increase in size and reduce thresholds, they will encounter the neutrino background, at which point Solar, atmospheric, and diffuse supernova neutrinos will interfere with a potential dark matter signal. Neutrino interactions in these detectors will occur through both coherent neutrino-nucleus scattering (CNS) and neutrino-electron elastic scattering (ES). In this talk, I will discuss how this neutrino background will drastically affect the discovery potential of upcoming ton-scale dark matter experiments. I will also review how we can go around this ultimate neutrino bound by combining data from different experiments, by searching for deviations in the annual modulation of the event rate and by measuring the direction of the recoiling nuclei.

Orateur: Dr Julien Billard (IPNL)

Slides 4_NeutrinoBackground_Moriond_Billard_s.pdf

18:20 break

18:45 Recent results from HESS/HESS2

Orateur: Dr Emmanuel Moulin (IRFU/SPP)

Slides 5_Emmanuel_MoriondEW2015_s.pdf

19:05 Planck 2014 Cosmological results

This talk will present the new 2014 measurements of the cosmological parameters made by the Planck collaboration on the Lambda-CDM model, illustrating both the Bayesian and the profile likelihood analysis. Extensions of Lambda-CDM will also be discussed with an emphasis on dark matter constraints.

Orateur: Mlle Sophie Henrot-Versille (lal)

Paper HenrotVersille.pdf

Slides 6_Planck_Sophie_MoriondEW_s.pdf

19:30 → 20:30 Young Scientist Forum 1

19:30 Determination of atmospheric neutrino mixing parameters and octant of θ23 at INO-ICAL detector

The India-based Neutrino Observatory (INO) is an approved atmospheric neutrino project, located at Theni (TamilNadu) in South India. A 50 kt magnetized Iron CALorimeter (ICAL) detector will be the main detector at INO for the determination of correct neutrino mass ordering, right octant of mixing angle θ23 and also for precise measurement of current mixing parameters. The detector will have modular structure and consists of a stack of 151 horizontal layers of 5.6 cm thick iron slab interleaved within 4 cm gap for the Resistive Plate Chambers (RPCs), which are the active detector elements. The uniqueness of this experiment is its charge identification ability hence it can distinguish between neutrino and anti-neutrino by identifying the charge of the leptons produced in the neutrino interaction with the iron target. We show the INO-ICAL sensitivity for the precision measurement of atmospheric neutrino oscillation parameters (sin^{2} θ23 & |∆m^{2}_{32}|) and the detector capability to determine the octant of mixing angle θ23 using muon neutrino events, generated through Monte Carlo NUANCE event generator. We have used the realistic resolutions and efficiencies obtained by the INO collaboration from GEANT4-based simulation. In the shed of recently measured large mixing angle θ13, a marginalised χ2 analysis has been performed using reconstructed neutrino energy and muon direction as observables. On the basis of this analysis we will present the physics potential of ICAL detector towards the precision measurement and octant sensitivity for 10 years of exposure.

Orateur: Mlle Daljeet Kaur (University of Delhi)

Paper Moriond_proceeding_daljeet.tar.gz

Slides 2_deBoissiere_EDW_Moriond_2015_s.pdf

19:37 EDELWEISS III

EDELWEISS is a dark matter direct-detection experiment, currently in its third phase. It operates cryogenic Germanium bolometers in the Underground Laboratory of Modane. A specific design of heat sensors and interleaved electrodes is used to efficiently reject background events. We present the status and performance of the ongoing physics run, in particular in view of low mass wimp searches.

Orateur: M. Thibault de Boissière (CEA)

Transparents Moriond_2015_deBoissiere_EDW.pdf

19:44 Making sense of the local Galactic escape speed estimates in direct dark matter searches

The knowledge of the high velocity tail of the WIMP velocity distribution function has a strong impact on the way direct detection (DD) may constrain or discover light WIMPs in the GeV mass range. Recently, there have been important observational efforts to estimate the so-called Galactic escape speed at the position of the Earth, like for instance the analysis published in early 2014 by the RAVE Collaboration (Piffl et al., 2014), which is of interest in the perspective of reducing the astrophysical uncertainties in DD. Nevertheless, these new estimates cannot be used blindly as they rely on assumptions in the dark halo modelling, which induce tight correlations between the escape speed and other local astrophysical parameters (circular velocity, dark matter density, distance to the Galactic center). We make a self-consistent study of the implications of the RAVE results on DD assuming isotropic DM velocity distributions, both Maxwellian and ergodic. Taking as reference the experimental sensitivities currently achieved by LUX, CRESST2, and SuperCDMS, we show that the uncertainties inferred for the exclusion curves in the low WIMP mass region are moderate. We discuss the level of (dis)agreement of these results with other independent astrophysical constraints.

Orateur: M. Stefano Magni (Université Montpellier 2)

Paper StefanoMagni.tar.gz

Slides 3_Magni_DDDM_TalkMoriond_s.pdf

19:51 Search for a sterile neutrino with the STEREO detector at ILL.

In 2011, a re-evaluation of the anti-neutrino spectrum emitted by nuclear reactors revealed a 6% deficit between the observed flux and the expected one. This anomaly is significant at 2.7sigmas and can be explain by a new oscillation at short range due to a light sterile neutrino, with parameter Δm² = 0.1-1 eV. The STEREO detector in construction at ILL will be the first ever to measure with precision the anti neutrino spectrum and flux at very short distance (9-11m) from the source of emitted neutrinos and it will be able to confirm or reject the existence of this light sterile neutrino. In this presentation I will introduce the relevant parameter to study the neutrino oscillation, the STEREO detector and its discovery potential.

Orateur: M. Stephane Zsoldos (LPSC)

Paper ZSOLDOS_EW2015.tar.gz

Slides 4_Zsoldos_STEREO_Moriond_EW2015_s.pdf

19:58 WIMP Annihilations in the Sun : A search using first year of operation of the completed IceCube neutrino telescope.

Weakly Interacting Massive Particles, which are possible candidates for Dark Matter can be gravitationally captured in the Sun and undergo self annihilation to produce standard model particles including neutrinos. The resulting neutrino flux from the Sun could be detected by terrestrial neutrino telescopes such as IceCube. In addition to the standard analysis using upward going neutrino induced events during Austral Winter, improved veto techniques have been used to reduce the atmospheric muon background and improve sensitivity during the Austral Summer. Overall sensitivity has also benefit from better analysis methods and reconstructions and improved with respect to all previous analyses. Results from the analysis of 341 days of operation of IceCube-DeepCore in the completed 86 string configuration will be presented.

Orateur: M. MOHAMED RAMEEZ (University of Geneva)

Paper RAMEEZ.zip

Slides 5_Rameez_IC_SolarWIMP_Moriond_s.pdf

20:05 NEMO-3 Analysis of the double-$\beta$ decay of 96Zr

The NEMO-3 detector was operated from 2003 to 2010 in the underground laboratory of Modane. Its main goal was the search for neutrinoless double-$\beta$ decay. Its discovery would prove that neutrinos are Majorana particles, meaning that the neutrino is its own antiparticle. This could help explaining the origin of the neutrino mass. The current best lower limits on the half-lives of this process are set around 10$^{24}$ - 10$^{25}$ years as obtained by the NEMO-3 experiment (for the 2$\beta$ isotope $^{100}$Mo) and other experiments. Several analyses are still ongoing, studying the different isotopes installed in NEMO-3: $^{100}$Mo, $^{82}$Se, $^{96}$Zr, $^{150}$Nd, $^{48}$Ca, $^{116}$Cd. A dedicated study on the double-$\beta$ decay processes of $^{96}$Zr to $^{96}$Mo has been performed using the entire detector live time of 5.25 yr for an exposure of 0.049 kg$\times$yr$^{-1}$. Even if only a small mass was placed in the detector, the transition energy in the double-$\beta$ decay is one of the highest among the double-$\beta$ isotopes. This is of first importance given the backgrounds coming from natural radioactivity. Therefore, $^{96}$Zr is a very promising isotope for the neutrinoless double-$\beta$ decay searches. During this conference, the measurement of the half-life of the two-neutrino process of $^{96}$Zr performed with the full statistics of NEMO-3 will be presented along with the current highest limit on the half-life of the neutrinoless double-$\beta$ decay process. Given that $^{96}$Zr is one of the isotopes able to undergo a double-$\beta$ decay to excited states, this process has also been investigated and the results of its search will be exposed.

Orateur: M. Guillaume Eurin (LAL, Orsay, France / UCL, London, UK)

Paper proceedings_moriond_eurin.pdf proceedings_moriond_eurin.tar.gz

Slides 6_Eurin_NEMO3_YSF_MoriondEw_2015_s.pdf

20:12 Radiative neutrino masses and dark matter

The Standard Model, despite its tremendous theoretical and experimental success, is known to lack explanation for several physical realities, namely gravity, dark energy, dark matter, and the neutrino masses. Of these, the last two are arguably related to the electroweak sector. Neutrino masses can be generated by different realizations of the Weinberg operator. In particular, radiative seesaw models, in which the Weinberg operator is realized with loops, have long been known as a viable solution. More recently radiative seesaw models have gained popularity in models connecting neutrino masses with dark matter, and several minimal models have appeared that address both issues simultaneously, which have proven to be an interesting theoretical possibility with a rich phenomenology. In this work we investigate the phenomenology of a variation of the scotogenic inverse seesaw model in which neutrino masses are generated through a one-loop radiative seesaw mechanism and which contains fermionic and scalar dark matter candidates. We find that the model is phenomenologically viable in the light of current dark matter and lepton flavor violation constraints.

Orateur: M. David R. Lamprea (Institut für Theoretische Physik, Universität Münster)

Slides 6_Lamprea_s.pdf

mardi 17 mars

08:30 → 12:00 The Scalar Sector: Morning session

08:30 Post-Inflation H relaxation and matter-antimatter asymmetry

Orateur: Alexander Kusenko (UCLA)

Paper kusenko.tar.gz

Slides kusenko_Moriond_50.pdf

08:50 Higgs and searches for new phenomena at the Tevatron

The Tevatron experiments complete their programs of searches for new physics using their full data samples. The most recent results come from CDF, with searches in the Higgs, heavy boson, magnetic monopole, and dark matter sectors. Constraints on models of the Higgs boson with alternative spin-parity quantum numbers than the SM prediction; a search for fermiophobic Higgs boson in triphoton final states; a search for heavy W' weak boson; a search for Dirac magnetic monopole; and a search for dark matter in final states with a leptonically decaying Z boson and large missing transverse energy will be presented. The spin-parity tests of the Higgs boson are performed in the VH(bb) channel and thus they are complementary to those performed in bosonic decay channels by the LHC experiments. The triphoton final states are explored for the first time. The searches provide exclusion limits competitive to those provided by other experiments in the same search channels.

Orateur: Dr Costas Vellidis (Fermilab)

Paper vellidis.tgz

Slides 2_Vellidis_MoriondEW2015_s.pdf

09:10 ATLAS Run1 final results, prospectives for Run2

Presentation of the main final ATLAS Run-I results on the Higgs boson on- and off-shell couplings, on the mass, spin/CP measurements and search for Higgs boson to invisible decays. This talk will concentrate on describing all the main results in the single channels, leaving the combination of channels to a dedicated talk later in the same session. Not covered: (1) searches for exotic/rare decay modes (ATLAS+CMS talk in the afternoon), (2) the top Yukawa coupling analyses will only briefly mentioned (covered by the ATLAS talk on top quarks in the top session). In the end some lessons & prospectives for Run-II will be briefly mentioned.

Orateur: Giacinto Piacquadio (SLAC)

Slides 3_ATLASHiggsRunIResults_GiacintoPiacquadio_s.pdf

09:30 CMS Run1 final results, prospectives for Run2 (and HL-LHC)

Presentation of final CMS Run 1 results for scalar signal strengths, mass, width and spin/CP. Focus will be on single-channel results in the main Standard Model channels. Prospects for Run 2 and HL-LHC will also be briefly discussed.

Orateur: M. Josh Bendavid (CERN)

Paper bendavid-moriondCMSScaler-2015-proceedings.tar.gz

Slides 4_Josh_Bendavid_moriondCMSScalar-Mar17-2015_s.pdf

09:50 break

10:15 ATLAS+CMS combination of Run1

Orateur: Michael Duehrssen

Slides 5_Duehrssen_Higgs_properties_v2.pdf

10:40 Effective Lagrangian facing experimental constraints

Orateur: Dr Francesco Riva (EPFL)

Paper Francesco_Riva.pdf

Slides 6_EFT_Moriond15_s.pdf

11:00 A middle way between kappas and Wilson coefficients

A middle way between kappas and Wilson coefficients

Orateur: M. Andre David (CERN)

Slides 150317_moriond_2015.pdf

17:00 → 19:30 The Scalar Sector: Afternoon session

17:00 Aligned two doublet model

I will discuss the phenomenology of models with two scalar doublets and no flavour-changing neutral currents at tree-level. Implications of flavour constraints and measurements of the 125 GeV scalar properties will be discussed keeping the generic Yukawa structure of the aligned two doublet model. Particular limits with a reduced number of free parameters, such as the usual models based on discrete Z2 symmetries will also considered.

Orateur: Alejandro Celis (Ludwig Maximilian University of Munich)

Paper Celis.zip

Transparents 1_Celis.pdf

17:20 Search for rare and exotic Higgs decays and production at the LHC: status and perspectives

I will review the status of the searches for BSM physics in the Higgs sector at the LHC performed by the ATLAS and CMS experiment. In particular, I will concentrate on rare and exotic Higgs decay and production modes. I will conclude giving perspectives for the Run 2 and beyond

Orateur: Dr Paolo Meridiani (INFN)

Paper moriond.pdf

Transparents 2_Meridiani_BSMHiggs_s.pdf

17:40 CMS High mass WW and ZZ Higgs search with the complete LHC Run1 statistics

A search for an additional Higgs boson in the $H \rightarrow WW$ and $H \rightarrow ZZ$ decay channels is reported. For Higgs boson masses in the range 145 < $m_H$ < 1000 GeV, limits from the search for a heavy resonance in the context of an electroweak singlet extension of the standard model are presented. Additionally, the combined upper limit at the 95% confidence level on the product of the cross section and branching fraction exclude a Higgs boson with standard model-like couplings in the range 145 < $m_H$ < 1000 GeV. The search is based upon proton-proton collision data samples corresponding to an integrated luminosity of up to 5.1 $fb^{-1}$ at $\sqrt{s}$ = 7 TeV and up to 19.7 $fb^{-1}$ at $\sqrt{s}$ = 8 TeV, recorded by the CMS experiment at the CERN LHC. Several final states of the $H \rightarrow WW$ and $H \rightarrow ZZ$ decays are analyzed.

Orateur: Dr Mario Pelliccioni (Istituto Nazionale di Fisica Nucleare)

Paper Pelliccioni.pdf

Transparents WWZZHighmass_Moriond15.pdf

18:00 EW vacuum stability depends upon Planck scale physics

According to the usual analysis, the presence of new physics at very high energy scales (Planck scale) has no impact on the stability condition of the EW vacuum, and the latter depends only on the values of the Higgs and top masses (M_H and M_t). However, it has been recently demonstrated that new physics interactions, even if they show up only at very high energies, can strongly affect the vacuum stability condition. As a consequence, the stability diagram of the Standard Model can be very different from the well known diagram (obtained ignoring new physics at the Planck scale) usually presented. This result has far reaching theoretical and phenomenological consequences. In particular, contrary to what is usually stated, higher precision measurements of M_t (and M_H) will not be able to tell us whether our universe lives in a stable or metastable vacuum state (or at the edge of stability).

Orateur: Prof. Vincenzo Branchina (University of Catania)

Paper branchinavinc.tar.gz

Slides 4_branchina.pdf

18:20 break

18:45 On the Origin of Scales and Inflation

This talk will be mainly based on the paper "Agravity" with arXiv number 1403.4226 [hep-ph]

Orateur: Dr Alberto Salvio (Universidad Autonoma de Madrid)

Paper Salvio-moriond.pdf

Transparents Moriond.pdf

19:05 The LHC machine: Run 2 and beyond

The LHC is exiting a two-year long shutdown (LS1) and the start of Run 2 is imminent. The key consolidation measures of LS1 are briefly recalled and the prospects for 2015 and Run 2 are outlined. The high luminosity LHC project (HL-LHC) is now well established. The key projects goals are enumerated and specific measures planned to meet the challenging luminosity targets are introduced. The LHC schedule for the next 20 years or so is presented.

Orateur: Mike Lamont (CERN)

Slides 6_Lamont_LHC-moriond-march15-v2.pdf

19:20 → 21:00 Young Scientist Forum 2

19:30 Evidence for Higgs boson decays to tau leptons with the ATLAS detector and prospects for future measurements

Recent results on the search for Higgs boson decays to tau leptons with the ATLAS detector are presented based on approximately 25 $\text{fb}^{-1}$ of proton-proton collision data collected at $\sqrt{s}=$ 7 and 8 TeV. Prospects of future measurements with proposed ATLAS upgrades at the High Luminosity LHC are also presented.

Orateur: M. Alexander Tuna (University of Pennsylvania (US))

Slides 1_Tuna-2015-03-17-tautau-05_s.pdf

19:37 One loop correction in the NMSSM with SloopS

We describe the on-shell renormalisation of the neutralino/chargino and sfermion sector of the NMSSM as implemented in Sloops, an automatized code for the calculation of one-loop process at colliders and in astroparticle physics. Applications to the computation of radiative corrections in decay of neutralinos are presented. A comparison of the results of different renormalization schemes is performed.

Orateur: Vincent Bizouard (LAPTh)

Paper Bizouard.pdf

Slides 2_Bizouard_Moriond.pdf

19:44 Dark Matter produced in association with top quark pair

LHC Search for Dark Matter produced in association with top quark pair is presented. The search is performed using 19.7 $\mathrm{fb}^{-1}$ of pp collisions recorded at a center of mass energy of 8 TeV with the CMS detector at LHC. The signature investigated is top quark pairs in semi-leptonic final state plus missing transverse energy. This work focuses in particular on Dark Matter production through scalar interaction where a proportionality to the quark mass is expected. This can enhance the discovery potential of the LHC under this assumption.

Orateur: Mlle Deborah Pinna (University of Zurich)

Paper DeborahPinna_MoriondProceeding.zip

Slides 3_PinnaDeborah_s.pdf

19:51 Search for a high mass SM-like Higgs boson at CMS in the H->ZZ decay channel at 8 TeV

A search for a high mass standard-model-like Higgs boson decaying into two Z bosons with subsequent decay into two leptons and two quarks has been performed at CMS based on 19.7 fb$^{−1}$ of proton-proton collisions produced in LHC at $\sqrt{s}$=8 TeV. The search uses different channels in order to isolate hypothetical Higgs boson-like signals in the mass range up to 1 TeV. The data is interpreted in terms of a standard-model-like Higgs boson as well as an electroweak singlet, visible through the interference with the recently discovered 125 GeV boson. No evidence of a signal is found and upper limits are set on the production times branching ratio cross section.

Orateur: M. Eduardo Navarro De Martino (CIEMAT (Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas))

Paper Proceedings_MoriondEW_ENavarroDeMartino.tar.gz

Slides 4_navarro_h2l2q_moriond_YSF2.pdf

19:58 One-loop effective non-linear Lagrangian with a light H-boson

We perform the off‐shell one loop renormalization of the chiral effective Lagrangian for a light (composite) Higgs particle up to four derivatives, based on a non‐linear realization of the $SU(2)_L \times U(1)_Y$ gauge symmetry. We consider the full would‐be Goldstone bosons and Higgs sector of the Lagrangian. As a result of off shell renormalization chiral non-invariant divergences appear. We have demonstrated how these divergences can be removed by field redefinitions and therefore proved that they have no impact on physical observables.

Orateur: M. Kirill Kanshin (INFN Padova/ University of Padova)

Paper KANSHIN.tar.gz

Slides 5_Kanshin_Moriond15.pdf

20:05 Signatures of dynamical scalars

Effective Lagrangians represent an important, model independent tool for studying new physics through the analysis of its impact at the electroweak scale. Depending on whether the new physics' dynamics is based on a linear or on a non-linear implementation of the electroweak symmetry breaking, a linear or a chiral Effective Lagrangian is expected to be most appropriate. The pattern of deviations from Standard Model predictions is different for the two descriptions: in this talk I will briefly present the main low-energy signals that allow to recognize whether the observed "Higgs" scalar is a dynamical (composite) particle or rather an elementary one.

Orateur: Mlle Ilaria Brivio (Universidad Autónoma de Madrid)

Paper proceedings_Brivio.tar

Slides 6_Brivio_MoriondEW_Signatures_dynamical_scalars.pdf

mercredi 18 mars

08:30 → 12:00 Standard Model

08:30 The global electroweak fit

We present an update of the global electroweak fit using electroweak next-to-next-to-leading order (NNLO) calculations for all precision observables that enter the fit. The availability of NNLO corrections allows for the first time the inclusion of realistic estimates of theoretical uncertainties due to missing higher orders. The knowledge of the mass of the Higgs boson improves the precision of the predictions in the global electroweak fit considerably and the global fits are used as powerful tools to assess the validity of the Standard Model and to constrain scenarios for new physics. We present updated constraints on two Higgs doublet models, dimension-6 operators and a model with modified Higgs couplings to bosons and fermions. We show that in many cases the Higgs signal strength measurements give complementary information to constraintes obtained from electroweak precison observables. Future measurements at the LHC and an expected e+e- collider promise to improve the experimental precision of key observables used in the fit. We assess the influence of present and future experimental and theoretical sources of systematic uncertainties on the fit predictions.

Orateur: Roman Kogler (University of Hamburg)

Slides 1_Kogler_Moriond_EW2015_s.pdf

08:50 En route to the W mass measurement

I discuss the requirements for a precise W boson mass measurement at the LHC, focusing on physics modeling aspects, and the role of theory and experiment in this endeavour.

Orateur: Dr maarten boonekamp (cea)

Paper Boonekamp.pdf

Slides 2_boonekamp_MwMoriond_43.pdf

09:15 EW measurements from ATLAS and CMS: Run1 legacy, prospects

The talk focuses on EWK measurements performed by the ATLAS and CMS collaborations. An overview of the Run1 results is presented together with prospects for the Run2

Orateur: Luca Perrozzi (ETH Zurich)

Paper moriond_proceedings.tgz

Slides 3_LPerrozzi_-_ATLASCMS_-_Other_EW_measurements_Run1_legacy_prospects_-_talk.pdf Luca_Perrozzi_moriond_proceedings.pdf

09:35 EW bosons exclusive radiative decays, SM and beyond

Orateur: Matthias Neubert (Johannes Gutenberg University Mainz)

Slides 4_neubert_moriond.pdf

10:00 break

10:20 ATLAS+CMS: Collecting and analysing data with 200 PU, (detector designs, analysis techniques, ...)

Detector layouts for the Phase 2 upgrades of ATLAS and CMS, designed for operation at the High-Lumionsity LHC (HL-LHC) under conditions with pile-up of 140 and beyond, will be presented and discussed. The event reconstruction performance and techniques implied by these detectors and experimental conditions will be demonstrated, and possibilities for further developments will be explored. The physics reach obtainable with the upgraded detectors at HL-LHC will be shown for a selection of possible HL-LHC measurements.

Orateur: Dr Nicholas Styles (Deutsches Elektronen-Synchrotron (DESY))

Paper NStylesMoriondEWProceedings.tar.gz

Slides 5_NStyles_ATLAS_CMS_HighPileup_MoriondEW.pdf

10:40 Improving LHC searches for strong EW symmetry breaking resonances

The talk will give a short overview of LHC limits on composite Higgs models, focusing on the role of vector resonances. Methods of refining direct searches for such resonances will be discussed.

Orateur: Mme Anna Kaminska (JGU Mainz)

Paper Kaminska.tar.gz

Slides 6_MoriondKaminska.pdf

11:00 Recent Electroweak Results from the Tevatron

In this contribution we present some recent results on the electroweak sector of the Standard Model, carried out by the CDF and D0 experiments. Deploying the p-pbar collision dataset at a center-of-mass energy of 1.96 delivered by the Tevatron collider it has been possible to perform precise measurement in this peculiar environment. The improvement on the measurement precision of the relevant observables in the electroweak sector allows to tighten indirectly the possible contribution from new physics.

Orateur: Dr Matteo Bauce (Sapienza Università di Roma)

Paper Proceedings_MoriondEW_2015_Bauce.tar.gz

Slides 7_Bauce_Tevatron_EWK.pdf

17:00 → 19:30 Top Physics

17:00 The 20th anniversary of the top quark discovery

Orateur: Dr Patrizia Azzi (INFN)

Paper Azzi.pdf

Slides 1_Top@20_MoriondEWK.pdf

17:20 Top Quark Physics at the Tevatron

The talk will discuss the latest results on top quark physics with the full Run II data set performed by the CDF and D0 experiments at the Fermilab Tevatron Collider. Results on electroweak top quark production include measurements of the $s$-, $t$- and $s+t$-channel cross section, as well as the extraction of the CKM matrix element $|V_{tb}|$. I will present inclusive and differential $t\bar{t}$ cross section measurements in strong top quark production, results on top quark properties including the top quark pole mass extraction from the inclusive $t\bar{t}$ cross section measurements, and the high precision direct measurements of the top quark mass. Top quark mass measurements and the latest Tevatron combination will be discussed in terms of their implications for electroweak fits. The talk will also highlight the latest updates on other properties, such as the forward-backward asymmetries and their implications, $t\bar{t}$ spin correlations and the top quark polarization.

Orateur: Andreas Jung (Fermilab)

Paper AndreasJung_MoriondEW2015.tar.gz

Slides 2_TopQuark_morew15_ajung.pdf

17:40 Precision on the top mass

In this talk I will discuss the theoretical issues related to precision measurements of the top mass.

Orateur: Stefan Weinzierl Weinzierl (University of Mainz)

Paper submit.tar.gz

Slides 3_weinzierl_moriond15.pdf

18:05 ATLAS+CMS top mass: current results and future measurements

The LHC experiments are fast catching up with Tevatron on the accuracy of the top quark mass ($m_{\rm t}$) measured using standard methods, with the latest CMS combination reaching an accuracy of 0.66 GeV compared to 0.64 GeV for Tevatron. The future prospects look promising as both ATLAS and CMS have commissioned new methods (3D-$R_{\rm lb}$, Z+b/Z+jet ratio) to address the leading systematic uncertainty from b-jet energy scale (bJES). At this level of precision the agreement between generator mass $m_{\rm t}^{\rm MC}$ and the theoretical pole mass $m_{\rm t}^{\rm pole}$ becomes relevant, and alternative methods are also explored.

Orateur: Dr Mikko Voutilainen (Helsinki Institute of Physics)

Paper proceedings-voutilainen-20150525.tar.gz

Slides 4_MoriondEW2015_topmass_voutilainen_v8.pdf

18:30 break

18:50 ATLAS+CMS top production and properties. Run1 Legacy

Orateur: Dr Andrey Loginov (Yale University)

Transparents loginov_top_is_great_moriond_ewk2015.pdf

19:30 → 21:20 Young Scientist Forum 3

19:30 New MSSM-SU(5) relations for the up-squarks

We investigate the consequences at low energies of a new MSSM-SU(5) induced symmetry relation in the up-squark sector. We show that this relation is not too much spoiled by the RGE running down to the electroweak scale and is kept relatively model independent. Therefore, it could bring us information on the possibility that a SU(5) symmetry holds at high energies assuming that the LHC will detect squarks and access, at least partially, to their flavour decomposition. In that purpose, we set up a statistical test based on a Bayesian approach and consider several cases, depending on the amount of flavour information the LHC will be able to collect on the up-squarks. This test relies on a Markov Chain Monte Carlo simulation whose results will be presented and which allows to test, given an observed low energy spectra, with which significance the spectra points toward a high scale SU(5) dynamic. The relevant low energies flavour constraints will also be included in the study in order to restrict our parameter space to a realistic case. The talk will be (partially) based on arXiv:1403.3397 and arXiv:1501.05307

Orateur: M. yannick stoll (LAPTh)

Slides 1_Stoll_Moriond_EW.pdf

19:37 Electroweak production of Zjj and hadronic activity in Zjj events at CMS

The measurement of the electroweak production cross section of a Z-boson in association with two jets in proton-proton collisions by the CMS experiment is presented. The cross section is measured in dielectron and dimuon final states and the measurement, combining different methods and channels is in agreement with the theory prediction.The hadronic activity in events with Z-boson production in association with jets is also studied, in particular in the rapidity interval between the associated forward/backward jets.

Orateur: M. Tom Cornelis (Universiteit Antwerpen)

Paper TomCornelis_MoriondEW2015.tar.gz

Slides 2_ewk_Z+2jets_Moriond.pdf

19:44 Limits and Fits from Simplified Models

With new results and limits on constrained models of supersymmetry (SUSY) from the ATLAS and CMS collaborations at the LHC, questions arise about what these limits imply for more general models of SUSY or other models for physics beyond the Standard Model. Since SUSY has a vast array of parameters, both collaborations also quantify their search results in terms of simplified models, augmenting the particle spectrum of the standard model with only a very limited set of new, hypothetical particles. In our work presented here, we focus on all-hadronic (multijet plus missing transverse energy) searches at the LHC and test the usability of simplified models parametrized by the squark and lightest SUSY particle (LSP) masses. By comparing results of these simplified models to more realistic models of squark production, we show that despite some underlying differences it is possible to use simplified models to estimate limits on both SUSY [1] and same-spin BSM [2] models. We also find good agreement [2] between our results and those of SModelS, a tool for interpreting simplified model LHC results [3]. Finally, we use simplified models for fits of supersymmetric models. [1] Edelhäuser, Heisig, Krämer, Oymanns, Sonneveld, *JHEP* **1412**, 022 (2014), [arXiv:1410.0965][1]. [2] Edelhäuser, Krämer, Sonneveld, in preparation. [3] Kraml et. al., *Eur. Phys. J.* **C74**, 2868 (2014), [arXiv:1312.4175][3]. [1]: http://arxiv.org/abs/1410.0965 [2]: http://phys.onmybike.nl/sonneveld_terascale14.pdf [3]: http://arxiv.org/abs/1312.4175

Orateur: Jory Sonneveld (RWTH Aachen)

Paper sonneveld.tar.gz

Slides 3_sonneveld_moriond15.pdf

19:51 Search for new light gauge bosons in Higgs boson decays to four-lepton events in pp collisions at √s = 8 TeV with the ATLAS detector

Some models beyond the Standard Model (BSM) suggest that the Higgs boson, discovered at the LHC during run I, can be used as a portal to look for New Physics. These models predict new sectors coupled to the SM whose presence can be inferred by observing SM final states. This opens the possibility of processes such as Higgs decays to dark vector bosons in four-leptons events, $H\rightarrow ZZ_d\rightarrow 4\ell$ and $H\rightarrow Z_dZ_d\rightarrow 4\ell$, where $Z_d$ is a BSM light gauge boson, and whose existence is motivated by Dark Matter candidate searches. The search of exotic Higgs decays uses the data taken in pp collisions with the ATLAS detector at the LHC at $\sqrt{s}=8$ TeV. Only electrons and muons are used. In the absence of a significant observed signal, upper bounds on the branching ratios of $H\rightarrow ZZ_d\rightarrow 4\ell$ and $H\rightarrow Z_dZ_d\rightarrow 4\ell$ relative to the branching ratio of $H\rightarrow 4\ell$ and to the SM branching ratio of $H\rightarrow ZZ^{(*)}\rightarrow 4\ell$ respectively, are set as a function of the mass of the dark vector boson at 95% C.L.

Orateur: Dr Daniela Paredes Hernández (Aristotle University of Thessaloniki)

Paper Moriond.tar.gz

Transparents 4_DanielaParedes.pdf

19:58 Performance of Boosted W-boson Identification at sqrt{s} = 8 TeV using the ATLAS detector

The high center-of-mass energy of the $pp$ collisions at the LHC enables searches for new particles with masses at the TeV scale. These heavy resonances can decay to final states with high $p_{\rm T}$ $W$- and $Z$-bosons. The hadronic decay modes of these bosons are of special interest of the potential increase in sensitivity for measurements and searches. However the cross-section of background events originating from light-quark and gluons jets is orders of magnitudes higher than the production of $W$-bosons. At large transverse-momentum, the decay products of the boson are collimated into one individual large-radius jets. Due to the high-luminosity conditions, soft particles unrelated to the hard scattering can contaminate the jets in the detector resulting in a diminished mass resolution. To enhance the sensitivity to new physics processes and to mitigate the influence of pile-up, jet grooming algorithms like trimming, pruning and mass-drop filtering have been designed. In addition substructure techniques are used to explore the internal structure of jets to distinguish between a two-body decay of a boson from a jet originating from gluons or light-quarks. Within the ATLAS collaboration the combination of grooming algorithm and substructure techniques have been extensively studied and are of key importance for the performance at an increased center-of-mass energy of 13 TeV.

Orateur: Chris Malena Delitzsch (Université de Genève)

Paper Delitzsch.pdf

Transparents Delitzsch_BoostedWbosonTagging_YSF_Moriond.pdf

20:05 Measurement of the \phi_{\eta}* distribution of muon pairs with masses between 30 and 500 GeV in 10.4 fb−1 of p\bar{p} collisions

We present a measurement of the distribution of the variable \phi_{\eta}* for muon pairs with masses between 30 and 500 GeV, using the complete Run II data set collected by the D0 detector at the Fermilab Tevatron proton-antiproton collider. This corresponds to an integrated luminosity of 10.4 fb^{−1} at \sqrt{s}= 1.96 TeV. The data are corrected for detector effects and presented in bins of dimuon rapidity and mass. The variable \phi_{\eta}* probes the same physical effects as the Z/γ∗ boson transverse momentum, but is less susceptible to the effects of experimental resolution and efficiency. These are the first measurements at any collider of the \phi_{\eta}* distributions for dilepton masses away from the Z/γ∗ \rightarrow l^{+}l^{-} boson mass peak. The data are compared to QCD predictions based on the resummation of multiple soft gluons.

Orateur: M. Xingguo Li (University of Manchester)

Paper YSF_XingguoLi.tar.gz

Transparents Moriond_EW_D0PhiStar_v2.pdf

20:12 SO(10) grand unification at next-to-leading order

Since the main experimentally testable prediction of grand unified theories is the instability of the proton, precise determination of the proton lifetime for each particular model is desirable. Unfortunately, the corresponding computation usually involves theoretical uncertainties coming e.g. from ignorance of the mass spectrum or from the Planck-suppressed higher-dimensional operators, which may result in errors in the proton lifetime estimates stretching up to several orders of magnitude. On the other hand, we present a GUT model based on SO(10) gauge group which is subsequently broken by a scalar adjoint representation, where the leading Planck-suppressed operator is absent, hence the two-loop precision may be achieved.

Orateur: Mme Helena Kolesova (Czech Technical University in Prague)

Paper

• kolesova.pdf
• kolesova.tex
• proton.pdf

Transparents SO10atNLO.pdf

jeudi 19 mars

08:30 → 12:00 Beyond SM: Morning session

08:30 Resonances in composite Higgs models

We study the scattering of longitudinally polarized W bosons in extensions of the Standard Model where anomalous Higgs couplings to gauge sector and higher-order operators emerge. These couplings should be thought of as the low-energy remnants of some new dynamics involving the electroweak symmetry breaking sector. By imposing unitarity and causality constraints on the WW scattering amplitudes, we find relevant restrictions on the possible values of the new couplings and predict the presence of new dynamical resonances above 300 GeV. We investigate the properties of these new resonances and their experimental detectability.

Orateur: Prof. Domenec Espriu (ICCUB-Universitat de Barcelona)

Paper moriond_ESPRIU.tar

Slides 1_Moriond15_ESPRIU.pdf

08:50 ATLAS+CMS: Boosted topologies (Run1 results, Run2 potential)

A summary of Run I analyses from ATLAS and CMS in boosted topologies is presented, focusing on hadronic final states. A brief overview of jet substructure techniques will also be presented, as well as prospects for Run II.

Orateur: Dr Stupak John (Purdue University Calumet)

Paper boostedTopologies_stupak.pdf

Slides 2_Stupak_BoostedTopologies_Final.pdf

09:15 SUSY: Blind spots @ run1, prospectives at Run2 and beyond

SUSY: Blind spots @ run1, prospectives at Run2 and beyond

Orateur: Dr Giacomo Polesello (INFN, Sezione di Pavia, Italie)

Slides 3_polesello_moriond.pdf

09:40 2h production with isotriplet scalars

The double SM-like $h$-boson production in the models with isospin-triplet scalars is studied. It is shown that in the see-saw type II model the mode with an intermediate heavy scalar, $pp\to H+X\to 2h+X$, may have the cross section which is comparable with that in the Standard Model. In the Georgi-Machacek model this cross section could be much larger than in SM since the vacuum expectation value of the triplet can be large.

Orateur: Dr Sergey Godunov (ITEP)

Paper godunov.tar.gz

Slides Godunov.pdf

10:00 break

10:25 Searches for supersymmetry in compressed scenarios

Searches for supersymmetric models with a compressed mass spectrum are presented using data samples corresponding to integrated luminosities of 19.4–19.7 fb$^{-1}$, collected at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. This class of model is challenging to detect experimentally, primarily due to low-momentum SM particles arising from decay chains involving SUSY particles of comparable mass. Various searches that are optimised for compressed-spectrum models are presented.

Orateur: Dr Robert Bainbridge (Imperial College London)

Paper bainbridge.tgz

Slides 5_Bainbridge_MoriondEW.pdf

10:45 Searches for long lived supersymmetric particles with the ATLAS detector

Several supersymmetric extensions of the Standard Model predict the existence of new particles whose lifetime can be comparable or longer than the time of flight through a collider detector. The direct detection of these particles, or of their decays inside the detector, requires dedicated experimental techniques. This talk presents recent ATLAS searches for supersymmetric particles with long lifetimes, performed with 20 fb$^{-1}$ of pp data of $\sqrt{s}$ = 8 TeV pp data. The results of searches for decays of gluinos, charginos or neutralinos inside the detector, as well as for the direct detection of long lived gluinos, squarks, charginos and sleptons are presented.

Orateur: Dr Helen Hayward (University of Liverpool)

Paper moriond_Hayward.tgz

Slides 6_Moriond2015_hayward_final.pdf

11:05 Top quarks in ATLAS: bridging measurements and searches

Orateur: Prof. Stephanie Majewski (University of Oregon)

Slides 7_MoriondEW2015_StephanieMajewski.pdf

17:00 → 17:45 Beyond SM: Afternnon session

17:00 ATLAS + CMS Exotic searches: Run 1 results, Run 2 prospectives

I will present the latest results of searches for new physics beyond the Standard Model (non-SUSY) from the ATLAS and CMS collaborations. I will also discuss prospects for searches for exotic phenomena during the LHC Run 2.

Orateur: Dr Katharine Leney (University College London)

Paper Katharine.Leney.tar.gz

Slides KLeney_Exotics_ATLAS+CMS.pdf

17:25 Invisible Z' and dark matter LHC vs LUX constraints

Orateur: Bryan Zaldivar

Paper ZALDIVAR_Moriond15_EW.tar

Slides zaldivar_moriond15.pdf

17:45 → 20:25 Celebrating the 50th Moriond

17:45 Carte blanche à Jacques Haissinski

Slides Présentation_Moriond_2015_ThomX.ppt

18:00 break

18:25 50 Years of Moriond

I will summarize the highlights of fifty years of high energy physics and the impact of Moriond on these achievements.

Orateur: Dr Daniel Treille (CERN)

Slides Moriond_Daniel_Treille.pdf

19:30 The early years of Moriond

Orateur: Guido Altarelli (CERN)

Slides Moriond'15.pdf

vendredi 20 mars

08:30 → 11:55 Heavy Flavours: Morning session

08:30 Latest results from B factories

I will briefly review recent results from Babar and Belle. For example, I will discuss probes for new physics in radiative penguin decays and the CP asymmetry in B0-B0bar mixing. I will also discuss direct searches for new physics, such as a light Higgs resonance or long lived particles.

Orateur: Eli Ben-Haim (LPNHE, IN2P3-CNRS, Universities of Paris VI)

Slides 1_Eli_BenHaim.pdf

08:55 Latest results on rare decays from LHCb

Rare flavour changing neutral current (FCNC) decays are sensitive indirect probes for new effects beyond the Standard Model (SM). In the SM, these decays are forbidden at tree level and are therefore loop-suppressed. In SM extensions, new, heavy particles can significantly contribute and affect both their branching fractions as well as their angular distributions. The rare decay $B^0\to K^{*0}(\to K^+\pi^-)\mu^+\mu^-$ is of particular interest, since it gives access to many angular observables, allowing to model-independently test the operator structure of the decay. A previous analysis of the angular distributions of the final state particles showed interesting tensions with SM predictions using the data sample taken by the LHCb detector during 2011. This talk will summarize latest results on rare decays from the LHCb experiment with emphasis on analyses of $b\to s\ell^+\ell^-$ processes, using the full Run I data sample of the LHCb experiment.

Orateur: Dr Christoph Langenbruch (University of Warwick)

Paper langenbruch_moriond_ew.tar.gz

Slides 2_Langenbruch_Moriond.pdf

09:20 B to K(*)mu+mu-: theory interpretation

Rare B decays constitute one of the cornerstones of the searches for the fundamental theory beyond SM. One of the golden modes in this search is the 4-body angular distribution $B \to K^*(\to K\pi)\mu^+\mu^-$. Sometime ago we proposed a basis of optimized observables called $P_i$ to fully describe this distribution and extract all the information from the Wilson coefficients. In 2013 LHCb presented the result of the measurement of our basis of optimized observables with 1fb$^{-1}$ dataset finding a clear and coherent pattern of deviations in different observables, specially in the observable $P_2$ (3 $\sigma$ in the second bin) and $P_5^\prime$ (4 $\sigma$ in the third bin, usually referred as “the anomaly"). We proposed a possible explanation of the observed deviations in terms of a new contribution to the Wilson coefficient $C_9$ of one of the semileptonic operators. In this talk I will present the theoretical status of this analysis with particular emphasis on the recent progress in the understanding of different SM sources of hadronic uncertainties: factorizable and non-factorizable power corrections, charm-loop effects as well as S-wave contribution. I will detail how these new SM contributions can be computed in a systematic way and how they affect the observables. Using the symmetries of the distribution we will present new links and implications between the $P_i$ observables that can help to disentangle hadronic from electroweak effects and open new directions in the search for New Physics. We will provide the most recent and precise theoretical predictions for the basis of optimized observables in the SM. We will also present the analysis of other decay modes like $B^+ \to K^+\mu^+\mu^-$ and $B^0\to K^0\mu^+\mu^-$ that nicely confirms the same deviation observed in $B \to K^*\mu^+\mu^-$. Finally we will discuss a possible explanation of the observed anomaly within a specific model.

Orateur: Prof. Joaquim Matias (Universitat Autonoma de Barcelona)

Slides moriondquim.pdf

09:40 Implications of $b\to s$ measurements for model-building

Recent measurements of rare decays based on the $b\to s$ transition, like $B\to K^*\mu^+\mu^-$, $B_s\to \phi\mu^+\mu^-$, and $B^+\to K^+\ell^+\ell^-$, have shown various tensions with Standard Model expectations. This talk will give an interpretation of these measurements, assuming that they are due to new physics rather than underestimated hadronic effects. First, a model-independent global fit taking into account all the relevant experimental results and updated theoretical inputs will be presented. Second, the implications of the fit results for several models of new physics will be discussed.

Orateur: Dr David Straub (Universe Cluster, TUM)

Slides 4_straub-moriond15.pdf

10:00 break

10:25 $CP$ violation in the $B_{(s)}^{0}$ system at LHCb

The LHCb experiment has a great potential for precise measurements of $CP$ violating phases in the Standard Model, and for searches of new phases. We report on recent LHCb measurements of $CP$ violating phases in neutral $B$ meson decays.

Orateur: Julian Wishahi (Technische Universität Dortmund)

Paper moriond_jwishahi.tar.gz

Slides 5_20150318_CPVintheBsSystem_MoriondEW.pdf

10:45 Constraining CKM gamma angle at LHCb

The current combination of all available tree-level measurements of the CKM angle gamma at LHCb is reported. It includes results obtained from time independent analyses of B+ -> DK+ and of B0 -> DK∗0 decays; and from a time-dependent analysis of Bs0 -> DsK decays. The results represent the world's best single-experiment determination of gamma. The first observation of the Bs->Ds*K decay and the first observation and amplitude analysis of B- -> D+K-pi- are also reported. In addition to these tree measurements, the estimation of gamma from charmless B meson decay, sensitive to loops contribution, is presented.

Orateur: M. Alexis VALLIER (LAL)

Proceedings MoriondEW2015_AlexisVallier.tar.gz

Slides 6_MoriondEW2015_GammaAngle_AlexisVallier.pdf

11:05 Lepton flavour Universality violation in B decays and new physics

Orateur: Andreas Crivellin (CERN)

Paper Crivellin_EW.pdf

Slides 7_Crivellin_MoriondEW2015-new.pdf

11:25 $|V_{ub}|$ with $\Lambda^{0}_{b} \rightarrow p\ \mu^{-}\bar{\nu}_{\mu} $ decays at LHCb

A measurement of the ratio of branching fractions between $ \Lambda^0_b \rightarrow p\ \mu^- \bar{\nu} $ and $ \Lambda^0_b \rightarrow \Lambda_c^+ \mu^-\bar{\nu} $ decays is performed using data corresponding to 2fb$^{-1}$ of integrated luminosity, collected by the LHCb detector. This combined with the latest form factor predictions obtained from lattice QCD calculations leads to the first determination of $\vert V_{ub} \vert$ at a hadron collider and in a baryon decay. The measurement achieves a relative precision of 7.3% which is more precise than any existing published exclusive measurements.

Orateur: M. William Sutcliffe (Imperial College London)

Paper Vub_proceedings_2.tar.gz

Slides 8_Sutcliffe_Vub.pdf

17:00 → 19:45 Heavy Flavours: Afternoon session

17:00 Unraveling flavor & naturalness from RUN II to 100 TeV

It is suggested that expectations of new physics at scales less than around few TeV, paying attention only to EW precision constraints may have been too optimistic. Perhaps the take home message from the absence of new physics signals in LHC to date is that flavor constraints also need attention. Once flavors are incorporated it becomes very difficult to lower the scale of new physics below about 10 TeV. Perhaps no radical changes to our notion of “naturalness” is required than our ability to probe above some such scale consistent with flavor constraints. Experimental possibilities at Run II and beyond will be discussed.

Orateur: amarjit soni (BNL)

Slides 1_EW_MORIOND_2015_soni.pdf

17:25 Charm mixing and CP violation at LHCb

LHCb has collected the world's largest sample of charmed hadrons. This sample is used to search for direct CP violation in the multibody prompt charm decays $D^0 -> \pi^-\pi^+\pi^0$. The search is employing an unbinned model independent method known as the energy test. Using the data collected by LHCb at centre-of-mass energy of 8 TeV, the world's best sensitivity to CP violation in this decay is achieved. The data are found to be consistent with the hypothesis of CP symmetry with a p-value of $(2.6 \pm 0.5)\%$. New measurements of indirect CP violation in muon tagged $D^0$ decays to two-body CP even final states are presented. The time dependent CP asymmetries in the decay rates of the singly Cabibbo-suppressed decays $D^0->KK$ and $D^0->\pi\pi$ decays using the full LHCb run 1 data set are determined to be $A_{\Gamma} (K^-K^+) = (-0.134 \pm 0.077 ^{+0.026}_{-0.034})\% ; A_{\Gamma} (\pi^-\pi^+) = (-0.092 \pm 0.145 ^{+0.025}_{-0.033})\%$, and are compatible with the hypothesis of no indirect CPV and with previous LHCb measurements.

Orateur: Dr Evelina Gersabeck (Heidelberg University)

Paper Gersabeck.pdf

Slides 2_EG_Moriond15.pdf

17:45 Recent Heavy Flavor Results from Tevatron

The run II at the Tevatron ended on september 2011 after a successful running and producing a plethora of results. Since then, the production of extraordinary results have not ended. Over the last year, 8 results on Heavy Flavor physics have been published with the complete dataset recorded at CDF and D0. In this talk we will give a short summary of the recent results on excited B-mesons, mass and lifetimes of b-baryons, lifetime on flavor specific Bs decay, direct and indirect CP violation in charm, and forward-backward asymmetries in b-hadrons.

Orateur: Dr Alberto Sanchez-Hernandez (CINVESTAV - Mexico City)

Slides 4_MDM-latflav.pdf

18:05 Lattice QCD inputs to flavor physics

TBA

Orateur: Prof. Michele Della Morte (CP3-Origins, SDU Denmark)

Paper DellaMorte.tar

Slides 4_MDM-latflav.pdf

18:30 break

18:55 ATLAS+CMS: Rare decays and other EW b-physics measurements

In b decay tree-level process with W exchange is hardly modified by new physics beyond the standard model; the search for new physics hints can be done by exploiting the sensitivity of some processes to loop diagrams. Such processes include rare FCNC decays, whose branching ratio could be modified by the presence of new degrees of freedom in the loops. Another process where new physics could show itself is Bs meson mixing, where the CP violation phase is predicted by SM to be very small and the observation of a significant violation would indicate the presence of new processes.

Orateur: Paolo Ronchese (INFN Padova)

Paper Ronchese.pdf

Slides 5_EW_HF_Meas_ATLAS_CMS.pdf

19:25 K to pi nunu in the SM and beyond

The precision expected for the rare $K \to \pi \nu\bar\nu$ decays by the NA62 and KOTO experiments in the coming decade will rival their current Standard Model (SM) predictions. In preparation for this upcoming opportunity, I will review the SM predictions and discuss the sensitivity of these decays to models beyond the SM. Of particular interest will be how models with constrained quark flavour symmetries could be discriminated using correlations between these and other rare decay processes. I will also discuss the smallest distance scales reachable in the LHC era from rare decays using as a benchmark a $Z'$ model, which for the kaon decays we find to be in the order of zeptometers i.e. they probe the "zeptouniverse".

Orateur: Robert Knegjens (TUM - IAS)

Paper moriondEW_knegjens.tar.bz2

Slides 6_moriond_knegjens.pdf

19:45 → 20:30 Young Scientist Forum 4

19:45 Study of the decay $B^{+} \rightarrow K^{+} \pi^{0}$ at LHCb

The capability of LHCb to measure the $B^{+} \rightarrow K^{+} \pi^{0}$ decay mode is investigated. Analysis techniques are developed to overcome the significant challenges facing measurements of this mode and other decay channels with similar topologies. Evidence of the decay is reported for the first time at a hadron collider, and prospects for measurements made with data from Run II of the LHC are presented.

Orateur: Jason Andrews (University of Maryland)

Paper AndrewsJE_proceedings.tar.gz

Slides 1_AndrewsJ.2015.03.20.Moriond.pdf

19:52 Testing left-right symmetric extensions of the Standard Model

The difference between left- and right-handed particles is perhaps one of the most puzzling aspects of the Standard Model (SM). In left-right models (LRMs) the symmetry between left- and right-handed particles can be restored at high energy. Due to this symmetry these models are quite predictive with regards to experimental observables, making them interesting beyond the SM candidates. This talk will review the most important features of the more symmetric LRMs. These include attractive aspects, like the symmetry between left and right and the natural implementation of the see-saw mechanism. The problem of the generally large fine-tuning in the Higgs sector in these models will also be addressed. Furthermore, an overview of the experimental constraints on these models will be given, con

Orateur: M. Wouter Dekens (Van Swinderen Institute, University of Groningen)

Paper W_Dekens.tar

Slides 2_Moriond2015_WDekens.pdf

19:59 Differential branching fraction and angular anaysis of $\Lambda_{b} \rightarrow \Lambda\mu^{+}\mu^{−}$ decays

The differential branching fraction of the rare decay $\Lambda_{b} \rightarrow \Lambda\mu^{+}\mu^{−}$ is measured as a function of $q^2$, the square of the dimuon invariant mass. The analysis is performed using data collected by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb$^{−1}$. This includes evidence for signal at $q^2$ below the square of the $J/\psi$ mass with significance above 3$\sigma$. In the $q^2$ intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon and hadron systems are measured for the first time.

Orateur: M. Luca pescatore (University of Birmingham, CERN)

Paper Moriond_EW_2015.zip

Slides 3_Pescatore_MoriondEW_Lmumu.pdf

20:06 Search for $B^+ \to \ell^+ \nu_\ell \gamma$ decays with hadronic tagging using the full Belle data sample

The semileptonic decay $B^+ \to \ell^+ \nu_\ell \gamma$ with $\ell^+ = e^+, \mu^+$ allows for the measurement of $\lambda_B$, which is the first moment of the $B$ meson distribution amplitude. This parameter is needed for the calculation of charmless hadronic $B$ decays in the QCD factorization scheme. The analysis is carried out with the full Belle data sample of $772\,\times 10^6 B \bar{B}$ pairs. One of the $B$ mesons is reconstructed in a hadronic decay channel and its momentum is used to compute the squared missing mass in the decay of the second signal-side $B$ meson. After an efficient signal selection a neural network is trained to separate signal and the main background $B^+ \to \ell^+ \nu_\ell \pi^0$. The signal is extracted in a fit to the squared missing mass in bins of the network output and a limit on the branching fraction is obtained which is the strongest to date.

Orateur: M. Andreas Heller (KIT)

Paper Heller_Andreas.tar.gz

Slides 4_HellerA-2015-03-20-Blnugamma.pdf

20:13 NA62 2014 Commissioning Run

NA62 aims to study the rare decay $K^+ \rightarrow \pi^+ \nu \bar{\nu}$ at the CERN SPS. The status of the experiment during the 2014 commissioning run will be presented. An overview of each subdetector and a first look at the 2014 data illustrate the general progress obtained in this run.

Orateur: M. Dario Soldi (Istituto Nazionale di Fisica Nucleare)

Paper Moriond2015_DarioSoldi.tar.gz

Slides 5_Moriond_Dario_Soldi.pdf

samedi 21 mars

09:00 → 11:30 Summaries

09:00 Experimental Summary

Orateur: Terry Wyatt

Slides 1_050321_twyatt_Moriond_Summary.pdf

09:45 Theory summary

Orateur: Alessandro Strumia

Slides 2_Strumia.pdf