Joerg Behr
21/07/2011 09:00
Parallel session talk
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...
Artem Baghdasaryan
21/07/2011 09:15
Parallel session talk
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...
Nicolas Houdeau
(LPTHE (CNRS - UPMC))
21/07/2011 09:30
QCD
Parallel session talk
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...
Keith Jarid Rose
21/07/2011 09:45
QCD
Parallel session talk
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.
Prof.
Panagiotis Kokkas
(University of Ioannina - Greece)
21/07/2011 10:00
QCD
Parallel session talk
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...
M.
Paolo Francavilla
(Universita' di Pisa)
21/07/2011 10:15
QCD
Parallel session talk
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...
Dr
Peter Svoisky
(University of Oklahoma)
21/07/2011 11:00
QCD
Parallel session talk
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...
Dr
Simone Alioli
(DESY)
21/07/2011 11:15
QCD
Parallel session talk
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.
M.
Raz Alon
(Weizmann Institute of Science)
21/07/2011 11:30
QCD
Parallel session talk
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...
Prof.
Zoltan Trocsanyi
(University of Debrecen)
21/07/2011 11:45
Parallel session talk
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...
David Miller
21/07/2011 12:00
Parallel session talk
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.
Dr
Leonardo Vernazza
(Johannes-Gutenberg-Universität)
21/07/2011 12:15
QCD
Parallel session talk
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.
Ignazio Scimemi
(Univ. Complutense de Madrid)
21/07/2011 12:30
QCD
Parallel session talk
Soft-Collinear Effective Theory (SCET) has been in covariant gauges. We argue that SCET, as it stands, is not capable to define in a gauge invariant way certain non-perturbative matrix elements that are an integral part of many factorization theorems. Those matrix elements involve two quark or gluon fields separated not only in light-cone direction but also in the transverse one. This...
Caterina Doglioni
21/07/2011 12:45
QCD
Parallel session talk
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...
Shiraz Habib
21/07/2011 14:30
Parallel session talk
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...
Vladimir Chekelian
21/07/2011 14:45
Parallel session talk
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...
Dr
Ji Young Yu
(LPSC)
21/07/2011 15:00
QCD
Parallel session talk
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...
Paul Laycock
21/07/2011 15:15
Parallel session talk
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...
Prof.
David d'Enterria
(CERN)
21/07/2011 15:30
QCD
Parallel session talk
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...
Dresden Deepak Kar
21/07/2011 15:45
QCD
Parallel session talk
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...
Dr
Yvonne Pachmayer
(University of Heidelberg)
21/07/2011 16:30
QCD
Parallel session talk
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....
Mauro Dinardo
21/07/2011 16:45
QCD
Parallel session talk
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...
Andreas Salzburger
21/07/2011 17:00
QCD
Parallel session talk
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...
Prof.
Svjetlana Fajfer
(Institute Jozef Stefan and Ljubljana University)
21/07/2011 17:15
QCD
Parallel session talk
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,...
Prof.
Antoni Szczurek
(Rzeszow University and Institute of Nuclear Physics PAN)
21/07/2011 17:30
QCD
Parallel session talk
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 $q \bar q$...
Olena Bachynska
21/07/2011 17:45
Parallel session talk
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...
Andreas Meyer
21/07/2011 18:00
Parallel session talk
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...
M.
Mykhailo Lisovyi
(DESY)
21/07/2011 18:15
Parallel session talk
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...
Dr
Luis Silva
(LIP Lisbon)
22/07/2011 09:00
QCD
Parallel session talk
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...
Marco Pappagallo
22/07/2011 09:15
QCD
Parallel session talk
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...
Dr
Frank Nerling
(University of Freiburg)
22/07/2011 09:30
QCD
Parallel session talk
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...
Emilie Passemar
(IFIC-University of Valencia)
22/07/2011 09:45
QCD
Parallel session talk
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...
Dr
Dmitri Melikhov
(HEPHY, Vienna, Austria & SINP, Moscow, Russia)
22/07/2011 10:00
QCD
Parallel session talk
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...
Dr
Federico Nguyen
(INFN Roma TRE),
Paolo Gauzzi
(Universita' degli Studi "La Sapienza" and Sezione INFN "Roma")
22/07/2011 10:15
QCD
Parallel session talk
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...
Dr
Jean-Loic Kneur
(LCC Montpellier)
22/07/2011 11:00
QCD
Parallel session talk
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...
Dr
Martha Constantinou
(University of Cyprus)
22/07/2011 11:15
QCD
Parallel session talk
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...
Umberto Tamponi
22/07/2011 11:30
QCD
Parallel session talk
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...
Jean Wicht
22/07/2011 11:45
Parallel session talk
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...
Elisa Guido
22/07/2011 12:15
QCD
Parallel session talk
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...
Elisa Guido
22/07/2011 12:30
QCD
Parallel session talk
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...
Andreas Hafner
22/07/2011 12:45
QCD
Parallel session talk
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...
M.
Yanxi ZHANG
(TUHEP)
22/07/2011 14:30
QCD
Parallel session talk
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...
Dr
Tomas Brauner
(Bielefeld University)
22/07/2011 14:45
Parallel session talk
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...
Fabrizio Palla
22/07/2011 15:00
QCD
Parallel session talk
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.
Dr
Hagop Sazdjian
(IPN, Universite Paris-Sud 11, Orsay)
22/07/2011 15:15
QCD
Parallel session talk
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...
Riccardo Brugnera
22/07/2011 15:30
Parallel session talk
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...
Johann Kuehn
(KIT)
22/07/2011 15:45
QCD
Parallel session talk
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)...
Amanda Cooper-Sarkar
22/07/2011 16:30
Parallel session talk
This talk will present a summary of QCD fits of H1 and ZEUS data to determine improved PDFs. The QCD fit analysis of the combined HERA-I inclusive deep inelastic cross sections has been extended to include combined HERA II measurements at high Q2. The precision of the PDFs at high-x is considerably improved - particularly in the valence sector. A preliminary NNLO QCD analysis is presented...
Mlle
Jennifer Bowles
(University of Glasgow)
22/07/2011 17:00
Parallel session talk
The HERMES experiment at DESY, Hamburg used the HERA 27.6GeV electron/positron polarised beam to study the structure of the nucleon. Deeply Virtual Compton Scattering (DVCS) provides access to Generalised Parton Distributions via measured azimuthal asymmetries at HERMES. Data was collected from 1995 to 2007 with unpolarised and both longitudinally and transversely polarised gas targets (H, D...
Dr
bernard Pire
(cpht polytechnique)
22/07/2011 17:15
QCD
Parallel session talk
Exclusive hard reactions have seen much recent progress, both theoretically and experimentally. I shall first review some new results on the Transition distribution amplitudes (TDAs) which appear in the QCD factorized amplitude of some "backward" exclusive processes (ref : Phys.Rev. D82, 094030,2010 and papers in preparation). I will also show new results on NLO QCD corrections for timelike...
Lorenzo Ortolan
22/07/2011 17:30
QCD
Parallel session talk
Inclusive Z-boson plus jets cross sections are measured in a final state where the Z-boson has decayed in two muons or electrons. Results are based on $\sim 6$ fb$ ^{-1}$ of data in $\rm p\bar{p}$ collisions at $\rm \sqrt{s}$ = 1.96 TeV collected with the CDF detector in Run II. Differential cross sections are presented as a function of several variables, among which jet transverse momentum,...
M.
Raoul Rontsch
(University of Oxford)
22/07/2011 17:45
QCD
Parallel session talk
The process W^+W^- + dijet is of great importance at the LHC, not only in itself but also as a primary background to moderately heavy Higgs production in association with two jets. I present next-to-leading order results for this process calculated recently using unitarity methods. By looking at specific kinematic distributions, I will show how the reduced theoretical uncertainty can improve...
Massimiliano Bellomo
22/07/2011 18:00
QCD
Parallel session talk
Cross sections, both inclusive and differential, and ratios of cross sections for W and Z boson production in proton-proton collisions are presented. The measurements are compared to the predictions of precise QCD calculations using and range of PDF fits. The impact of these measurments on evvnt generators, future fits and their uncertainties is studied.
M.
Bjoern Penning
(University of Freiburg)
22/07/2011 18:15
QCD
Parallel session talk
We present measurements of inclusive W/Z + n jet cross sections (n=1-4), presented as total inclusive cross sections and differentially in the $n^{th}$ jet transverse momentum and rapidity, as well as the heavy flavor content in these jets up to n=2. The measurements are made using 4.2 to 6 fb$^{-1}$ of data collected by the D0 detector at the Fermilab Tevatron Collider. The measurements are...
Nicolas Pierre Chanon
23/07/2011 09:00
QCD
Parallel session talk
A measurement of the differential cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a center-of-mass energy sqrt(s)=7 TeV is presented. The data sample corresponds to an integrated luminosity of 36/pb recorded by the CMS detector at the LHC. Photons are required to have a pseudorapidity |η|<2.5 and ET>25 GeV. Photon candidates are identified...
Francesco Polci
23/07/2011 09:15
QCD
Parallel session talk
Measurements of the cross section for the inclusive production of isolated prompt photons, photons produced in association with jets and diphotons in pp collisions at a centre-of-mass energy sqrt(s) = 7TeV are presented. Photon candidates are identified by combining information from the calorimeters and from the inner tracker. Residual background in the selected sample is estimated from data...
Peter Bussey
23/07/2011 09:30
Parallel session talk
Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320pb-1. Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges 4 < ET < 15 GeV and -0.7 < eta < 0.9 for exchanged photon virtualities, Q2, in the range 10 < Q2 < 350 GeV and for
invariant masses of the hadronic...
Dr
Costas Vellidis
(Fermilab)
23/07/2011 09:45
QCD
Parallel session talk
We report a measurement of the cross section of prompt isolated photon pair production in ppbar collisions at a total CM energy of 1.96 TeV using data of 5.4/fb integrated luminosity
collected with the CDF II detector at the Fermilab Tevatron.
The measured differential cross section
is compared with three perturbative QCD predictions,
a Leading Order (LO) parton shower Monte Carlo and...
Prof.
Nikolay SKACHKOV
(Joint Institute for Nuclear Research)
23/07/2011 10:00
QCD
Parallel session talk
Samples of inclusive $\gamma+{\rm 2~jet}$ and $\gamma+{\rm 3~jet}$ events collected by the D0 experiment
with an integrated luminosity of about 1~fb$^{-1}$ in $p\bar{p}$ collisions
at $\sqrt{s}=1.96$ TeV are used to measure cross sections
as a function of the angle in the plane transverse to the beam direction
between the transverse momentum ($p_T$)
of the $\gamma+$leading jet system...
Erik Brucken
23/07/2011 10:15
QCD
Parallel session talk
We present the first observation and cross section measurement of exclusive photon pair production in proton-antiproton collisions at center-of-mass energy of 1.96 TeV using data taken by the Run II Collider Detector at Fermilab.
We select events with two electromagnetic showers, each
with transverse energy ET greater than 2.5 GeV and pseudorapidity, $\rm |\eta|$ < 1.0, with no other...
Hannes Jung
23/07/2011 11:00
Parallel session talk
We present measurements of the forward (3 < |eta| < 5) energy flow in minimum bias events and in events with either hard jets or W and Z bosons produced at central rapidities, as well as measurements of the inclusive forward jet cross section and of associated production of forward and central jets. The dijet "k-factor", defined as the ratio of the inclusive to the exclusive dijet cross...
Jonathan Jason Hollar
23/07/2011 11:15
Parallel session talk
A measurement of the total, inelastic pp cross section at 7 TeV, based on the observation of pile-up events, is presented.
Measurements of soft and hard diffractive processes obtained with the CMS detector at various centre-of-mass energies are presented and compared with the PYTHIA6, PHOJET and PYTHIA8 Monte Carlo generators. The ratio of diffractive to inclusive jet production is obtained...
Prof.
Bozzo Marco
(INFN Genova)
23/07/2011 11:30
QCD
Parallel session talk
The TOTEM experiment at the LHC, placed symmetrically with respect to the CMS Interaction Point IP5, is optimized to measure in dedicated special-optics runs, luminosity independently, the total pp cross-section and to study elastic pp scattering over a wide range in momentum transfer from -t ~ 10 -3 to 10 GeV2. Furthermore, diffractive dissociation, including single, double and central...
Thomas Ruf
23/07/2011 11:45
Parallel session talk
The phase space coverage of the LHCb detector allows a unique insight into the
particle production in the forward region at the LHC. Due to its unique pseudorapidity
coverage and the possibility of extending the measurements to low transverse
momenta, the LHCb data provide important input to the understanding of particle
production in a kinematical range where QCD models have large...
Dr
Martin Hentschinski
(IFT-UAM Madrid)
23/07/2011 12:00
QCD
Parallel session talk
We present a definition of an unintegrated seaquark density
for the LO CCFM Monte-Carlo CASCADE and discuss determination of a NLO
BFKL unintegrated gluon density from a fit to combined HERA data. The
kT-dependent sea-quark density is defined using high energy
factorization, while the quark-gluon splitting is treated with exact
kinematics. The latter is found to agree with the...
Dr
Samuel Wallon
(LPT Orsay and UPMC university)
23/07/2011 12:15
QCD
Parallel session talk
We present the first next-to-leading BFKL study of the cross section and azimuthal decorrellation of Mueller Navelet jets. This includes both next-to-leading corrections to the Green's function and next-to-leading corrections to the Mueller Navelet vertices. The obtained results for standard observables proposed for studies of Mueller Navelet jets show that both sources of corrections are of...
Richard Polifka
23/07/2011 12:30
Parallel session talk
The cross section for the diffractive deep-inelastic scattering process ep -> e X p is measured, with the leading final state proton detected in the H1 Forward Proton Spectrometer. The data are compared to perturbative QCD predictions at next-to-leading order based on diffractive parton distribution functions previously extracted from complementary measurements of inclusive diffractive...
Paul Laycock
23/07/2011 12:45
QCD
Parallel session talk
The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC for electron-proton scattering, through the addition of a new electron accelerator. This contribution, which is derived from the draft CERN-ECFA-NuPECC Conceptual Design report (due for release in 2011), addresses the expected impact of the LHeC precision...
