Denis Bertin
(Vice-président Aix-Marseille Université),
Eric Kajfasz
(Directeur du Centre de Physique des Particules de Marseilles)
22/04/2013, 09:00
Voica Ana Maria Radescu
(Deutsches Elektronen-Synchrotron (DE))
22/04/2013, 10:00
Markus Diehl
(DESY)
22/04/2013, 14:00
Piergiulio Lenzi
(Universita e INFN (IT))
22/04/2013, 14:40
Michiel Sanders
(Ludwig-Maximilians-Univ. Muenchen (DE))
22/04/2013, 17:10
Seema Sharma
(Fermi National Accelerator Lab. (US))
22/04/2013, 17:50
Stanislav Shushkevich
(Deutsches Elektronen-Synchrotron (DE))
23/04/2013, 08:30
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
A measurement of the integrated luminosity at the ep collider HERA is presented, exploiting the elastic QED Compton process ep \rightarrow ep. The electron and the photon are detected in the backward calorimeter of the H1 experiment. The integrated luminosity of the data recorded in 2003 to 2007 is determined with a precision of 2.3%. The measurement is found to be compatible with the...
Karin Daum
(University of Wuppertal/DESY)
23/04/2013, 08:30
The cross section for ep -> e b\bar{b} X in photoproduction is measured with the H1 detector at the ep-collider HERA. The decay channel b\bar{b} -> ee X' is selected by identifying the semi-electronic decays of the b-quarks. The total production cross section is measured in the kinematic range given by the photon virtuality Q^2 <= 1 GeV^2, the inelasticity 0.05 <= y <= 0.65 and the...
Sabino Meola
(Universita e INFN (IT))
23/04/2013, 08:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
CMS results are presented on the measurement of properties of the Higgs-like particle discovered last summer with a mass in the range of 125-126 GeV, based on the full statistics of about 25 fb-1, collected in 2011 and 2012 at 7 and 8 TeV respectively. A discussion will be given on the mass measurement, couplings and the spin-parity properties of this new particle. The most recent results will...
Dr
Krzysztof Kutak
(Instytut Fizyki Jadrowej Polskiej AkademiiNauk)
23/04/2013, 08:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Motivated by p-Pb experiments at Large Hadron Collider which require both knowledge of gluon densities accounting for saturation and for processes at a wide range of $p_t$ we study basic momentum space evolution equations of high energy QCD factorization. Solutions of those equations might be used to form a set of gluon densities to calculate observables in generalized high energy...
Rafal Maciula
(Institute of Nuclear Physics PAN)
23/04/2013, 08:50
Part 1:
-------
We discuss production of charmed mesons in proton-proton collisions at the LHC. The cross section for inclusive production of $c \bar c$ pairs is calculated in the framework of the $k_{\perp}$-factorization approach. Taking wide range of $x$ values necessary for the calculation we use and test several unintegrated gluon distributions from the literature. Some of them include...
Mr
Gevorg Karyan
(A.I. Alikhanyan National Science Laboratory)
23/04/2013, 08:50
The HERMES collaboration has measured charge-separated pion and kaon multiplicities in semi-inclusive deep-inelastic scattering using a 27.6 GeV electron or positron beam scattering off a hydrogen or deuterium target. The results are presented as functions of the Bjorken variable x, the negative squared four-momentum transfer Q2, a hadron fractional energy z and the hadron's transverse...
Dr
Amir Rezaeian
(Universidad Técnica Federico Santa María)
23/04/2013, 08:50
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
The Impact-Parameter dependent Saturation Model is a simple dipole model that incorporates key features of the physics of gluon saturation and matches smoothly to the perturbative QCD dipole expression at large Q^2 for a given x. It was previously shown that the model gives a good description of HERA data suggesting evidence for gluon saturation effects at small x. The model has also been...
Andre Georg Holzner
(Univ. of California San Diego (US))
23/04/2013, 08:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Results are presented on the study and search for Higgs-like particles decaying into a ZZ, WW and 2 photon final states, based on the full statistics of about 25 fb-1, collected in 2011 and 2012 at 7 and 8 TeV respectively with the CMS experiment. Different production channels namely inclusive, VBF and associated production are studied for the 2-photon final state. The following ZZ decay...
Ian Brock
(Universitaet Bonn (DE))
23/04/2013, 08:55
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The cross sections for neutral current deep inelastic scattering in
e+p collisions with a longitudinally polarised positron beam have been
measured using the ZEUS detector at HERA. The single-differential
cross-sections dsigma/dQ2, dsigma/dx and dsigma/dy and the
double-differential cross sections in Q2 and x are measured in the
kinematic region Q2 > 185 GeV2 for both positively and...
Alexandr Kozlinskiy
(NIKHEF (NL))
23/04/2013, 09:10
The LHCb experiment has accumulated more than 3 fb-1 of data in proton-proton collisions data at different centre of mass energies, collecting a sample rich in charm and beauty hadrons.
Studies of the production of these states provide a wealth of new measurements as well as probes of theory predictions. We will present studies of charm and beauty production including measurements
of the...
Nour Makke
(Universita e INFN (IT))
23/04/2013, 09:10
Fragmentation functions (FFs), which turn partons into non-perturbative hadronic bound states in hard-scattering reactions, represent a key ingredient to address proton spin structure in semi-inclusive deep inelastic scattering and proton-proton collisions. Fragmentation functions can not be determined from perturbative Quantum Chromodynamics and have to be extracted from experimental data in...
Martin Hentschinski
(Brookhaven National Laboratory)
23/04/2013, 09:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We review Lipatov's high energy effective action and show that it is a useful computational tool to calculate QCD scattering amplitudes in the high energy limit. We explain in some detail our recent work where a novel regularization and subtraction procedure has been proposed that allows to extend the use of this effective action beyond tree level. As explicit results we discuss the derivation...
Somnath Choudhury
(CEA - Saclay (FR))
23/04/2013, 09:10
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Results are presented on the study of the Higgs-like particle at 125 GeV decaying into final states consisting of either two taus, or a b anti-b quark pair, based on the full statistics of about 25 fb-1, collected in 2011 and 2012 at 7 and 8 TeV respectively with the CMS experiment. Leptonic and hadronic decay channels for the tau lepton are included in the search. Different production...
Sergey Alekhin
(DESY-Zeuthen)
23/04/2013, 09:15
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We report on an update of the ABM NNLO PDF fit, which includes recent LHC data on the W- and Z-boson production along with their experimental uncertainties. We illustrate the constraints on PDFs coming from those LHC data and we also perform a determination of the strong coupling constant alpha_s. Cross section predictions for important benchmark processes at the LHC will be presented.
Dr
Charlotte Van Hulse
(University of the Basque Country UPV-EHU)
23/04/2013, 09:30
Multiplicities and azimuthal asymmetries were extracted from e+e−
annihilation data collected with the Belle detector. These data were taken at the KEKB e+e− collider at a center-of-mass energy of
sqrt(s) = 10.52 GeV. The multiplicities provide the cleanest access to spin-independent fragmentation functions, which describe the hadronization of quarks into final-state hadrons. The low...
Grigorios Chachamis
(IFIC (CSIC/UV) Valencia)
23/04/2013, 09:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Lipatov's high energy effective action is proving to be a useful computational tool for studying QCD scattering amplitudes in the high energy limit. We explain how we calculate within this framework the full gluon Regge trajectory at two loops using a novel regularization and subtraction procedure.
Pier Paolo Giardino
(Sezione di Pisa (IT))
23/04/2013, 09:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The recently discovered resonance at 125 GeV has properties remarkably close to those of the Standard Model Higgs boson.
Therefore, it is fundamental to investigate them thoroughly.
I will review the status of our understandings of this particle's properties and I will show the results of our fits of all presently available data.
2.
High precision measurement of the form factors of the semileptonic decays K+- -> pi0 l+- nu (Kl3)
Dmitry Madigozhin
23/04/2013, 09:30
Semileptonic kaon decays offer the most precise determination of the
CKM matrix element |Vus|. The experimental precision is however
limited by the knowledge of the form factors of this decay, since
these enter both the phase space integral and the detector
acceptances.
The NA48/2 experiment presents new measurements of the form factors of
the semileptonic decays of charged kaons, based...
Elvira Rossi
(Universita e INFN, Roma I (IT))
23/04/2013, 09:30
A new measurement of production cross of B+ is presented.
The double differential cross section is measured over the range |y| < 2.25 and 9 < pT <120 GeV, much wider than in previous measurements. Comparisons with next-to-leading order theoretical predictions (POWHEG+PYTHIA, MC@NLO+HERWIG and FONLL) are discussed.
Alberto Accardi
(Hampton U. and Jefferson Lab)
23/04/2013, 09:40
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
I present three new sets of next-to-leading order parton distribution functions (PDFs) determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed for the description of deep inelastic scattering data at large x and low Q^2, and nuclear corrections for deuterium targets. The PDF sets correspond to...
James Alexander Kraus
(University of Mississippi (US))
23/04/2013, 09:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
We present the combination of searches for the Standard Model Higgs boson at a center-of-mass energy of sqrt(s)=1.96 TeV, using the full Run 2 dataset collected with the D0 detector at the Fermilab Tevatron collider. The major contributing processes include associated production (WH-->lvbb, ZH-->vvbb, ZH-->llbb, and WH-->WWW(*)) and gluon fusion (gg-->H-->WW(*)). The significant improvements...
Mario Galanti
(Universita e INFN (IT))
23/04/2013, 09:50
The large production cross-sections at LHC energies, combined with an adapted trigger strategy has enabled CMS to collect large data samples to perform detailed studies of Beauty hadron properties. In this talk we will report from our latest results, including Lambda_b production cross-section and lifetime measurements, bbbar cross-section differential in the opening angles deltaPhi and deltaR...
Harold E Jackson Jr
(Argonne National Laboratory)
23/04/2013, 09:50
In 2008 HERMES published the results of an ``isoscalar'' extraction
in leading logarithmic order (LO) in the strong coupling constant of
quantum chromodynamics of the momentum and helicity density distributions of the strange sea in the nucleon from the charged-kaon production in deep-inelastic scattering (DIS) on the deuteron (Phys. Lett. B666, 446 (2008). The shape of the momentum...
Michal Deak
(IFIC/CSIC, Universitat de Valencia)
23/04/2013, 09:50
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We solve the modified non-linear extension of the CCFM equation – KGBJS equation – numerically for certain initial conditions and compare the resulting gluon Green functions with those obtained from solving the original CCFM equation and the BFKL and BK equations for the same initial conditions. We improve the low transversal momentum behaviour of the KGBJS equation by a small modification.
Prof.
Pavel Nadolsky
(Southern Methodist University)
23/04/2013, 10:05
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
I discuss recent developments in the CTEQ-TEA global analysis
of parton distribution functions
Isabella Garzia
(INFN)
23/04/2013, 10:10
Dr
Andreas van Hameren
(IFJ PAN)
23/04/2013, 10:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
While several approaches and their implementations for the
efficient calculation of scattering amplitudes within collinear
factorization applied to hadron scattering exist, no automated tool
exist to achieve the same within frameworks of factorization that
allow for the initial-state partons, entering the hard partonic
process, to have non-vanishing transversal momentum components....
Prof.
Robert Thorne
(University College London)
23/04/2013, 11:00
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
I discuss the recent developments relating to the MSTW series of PDFs. I discuss the issues associated with heavy flavour and the influence of some recent data sets.
Dr
Zhijun Liang
(University of Oxford)
23/04/2013, 11:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The integrated and differential fiducial cross sections for the production of a W or Z boson in association with a high-energy photon are measured using 7 TeV pp collisions. Events are selected using leptonic decays of the W and Z bosons. The data are used to test the electroweak sector of the Standard Model and search for evidence for new phenomena. The measurements are used to probe...
alessandro bertolin
(INFN - Sez. di Padova)
23/04/2013, 11:00
The double differential inelastic J/psi photoproduction cross section
as function of the squared transverse momentum of the J/psi in bins of the
inelasticity z has been measured in ep collisions with the ZEUS detector
at HERA.
An integrated luminosity of 468 pb-1 was used corresponding
to the full data sample collected by the ZEUS experiment.
The events were required to have 0.1 <...
Stephane Munier
(Ecole polytechnique)
23/04/2013, 11:00
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Perturbative QCD is the appropriate tool to describe many important properties of the inclusive observables measured at electron-proton (or ion) colliders, such as the energy dependence of the total cross sections in well-chosen kinematical regions. This is because the electron may effectively be replaced by its cloud of photons, whose virtualities provide a hard scale.
At hadron colliders...
Dr
Michela Chiosso
(INFN, Sezione di Torino and University of Torino)
23/04/2013, 11:00
Much of the information that exists today about Transverse Momentum
Dependent Parton Distribution Functions (TMDs) comes from SIDIS
measurements with unpolarised and polarised beams and targets where they appear convoluted with fragmentation functions (FFs).
Drell-Yan (DY)measurements are complementary to those by SIDIS experiments, as they allow to measure convolutions of only PDFs...
Mirko Berretti
(Sezione di Pisa (IT))
23/04/2013, 11:20
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
The TOTEM experiment at the LHC has performed the first luminosity-independent measurements of the total proton-proton cross-section at sqrt(s) = 7 TeV and 8 TeV. These measurements are based on the optical theorem and require simultaneous measurements of the elastic rate by measuring the outgoing protons with Roman Pots and of the inelastic rate, accomplished with the forward charged-particle...
Martin Zeman
(Czech Technical University (CZ))
23/04/2013, 11:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Diboson production cross sections have been measured for WW, WZ and ZZ pairs at 7 and 8 TeV pp collisions using the ATLAS detector. The measurements require heavy bosons to decay leptonically, including the Z->nu nu decay channel. The results are first obtained in phase space regions defined by the decay kinematics and then extrapolated to the full phase space. The measurements are compared...
Darren Price
(Indiana University (US))
23/04/2013, 11:20
The programme of measurement on quarkonia production performed by ATLAS in discussed. Particular emphasis is placed on the recent study of Y(1S), Y(2S) and Y(3S).The collected data extends to transverse momentum up to 70 GeV, much higher than in previous studies. The results are compared to theoretical models of Y production, which do not provide an accurate description of the data over the...
Orel Gueta
(Tel Aviv University (IL))
23/04/2013, 11:20
The internal structure of jets produced in proton-proton collisions at 7 TeV centre-of-mass energy provides a direct test of QCD calculations of gluon and quark radiation, as well as having sensitivity to hadronisation and underlying event. The transverse energy distribution around the jet core has been measured, as well as the fragmentation of a jet into charged particles. Jet shapes -...
Mr
Nathan Hartland
(University of Edinburgh)
23/04/2013, 11:25
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
An accurate and reliable determination of parton distribution functions is vital to fully exploit the potential of the LHC. However the LHC itself also has the ability to provide substantial constraints upon existing PDF determinations. We shall discuss the tools available to study the impact of LHC measurements upon PDFs and discuss the NNPDF2.3 PDF set, which includes constraints from LHC...
Abhay Deshpande
(Stony Brook University)
23/04/2013, 11:25
How are the sea quarks, gluons, and their spins distributed in space and momentum inside the nucleon? Where does the saturation of gluon densities set in? How does the nuclear environment affect the distribution of quarks and gluons and their interactions in nuclei? These are profound and compelling questions in QCD that have (evolved and) remain unanswered despite decades of (success of, and)...
Frank Siegert
(Albert-Ludwigs-Universitaet Freiburg (DE))
23/04/2013, 11:40
A measurement of splitting scales in the kt clustering algorithm for final states containing a W boson produced in proton-proton collisions is presented. The measurement focuses on the four hardest splitting scales in a kt cluster sequence of the hadronic activity accompanying the W boson, and suitably defined ratios.
The data are compared to predictions from various Monte Carlo generators....
Brian Edward Lindquist
(State University of New York (US))
23/04/2013, 11:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A study of WW/WZ production in the semileptonic final state using proton-proton
collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector is presented.
The cross section is measured in the WW/WZ -> lepton nu q¯q?
decay channel where the lepton can be a muon or an electron.
The measured cross section is consistent with the Standard Model expectation.
Joao Seixas
(Instituto Superior Tecnico (PT))
23/04/2013, 11:40
In the present talk we will present results from a large data sample collected at 7 TeV, from which CMS could extensively study the polarization of the 3 Upsilon states, as a function of pT in two rapidity windows, conducting a complete analysis, including the polar and azimuthal anisotropy angles, and in 3 different polarization frames.
Thanks to the large data sample, CMS could also...
Prof.
Konstantin Goulianos
(The Rockefeller University)
23/04/2013, 11:40
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Predictions of diffractive, elastic, total, and total-inelastic pp cross sections based on the renormalization model for diffraction are compared with recent measurements at the LHC.
Ringaile Placakyte
(Deutsches Elektronen-Synchrotron (DE))
23/04/2013, 11:50
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The proton parton distribution functions (PDFs)
are essential for precision physics at the LHC
and other hadron colliders. Their current level
of accuracy dominates the theory uncertainties
in Higgs production and it affects substantially
theory predictions for Beyond Standard Model
high mass production.
The determination of the PDFs is a complex
endeavor involving several physics...
Cynthia Keppel
(Jefferson Lab)
23/04/2013, 11:55
Construction of the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) is presently underway. This upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and the construction of upgraded detector hardware. The result will be an exciting physics...
David Wardrope
(University College London (UK))
23/04/2013, 12:00
An inclusive jet multiplicity ratio is sensitive to the strong coupling constant alpha_S and has reduced sensitivity to the uncertainties due to parton distribution functions.
The ATLAS data are used to determine the strong coupling’s strength at the highest energy scales. The results probe the consistency of the running of the coupling as predicted by QCD.
Conor Fitzpatrick
(CERN)
23/04/2013, 12:00
The latest years have seen a resurrection of interest in searches for exotic states motivated by tantalising observations by Belle and CDF. Using the data collected at pp collisions at 7 and 8 TeV by the LHCb experiment we present limits on the X(4140) and studies of the X(3872) quantum numbers. Future prospects for other exotic states will be discussed.
Tristan Arnoldus Du Pree
(Universite Catholique de Louvain (BE))
23/04/2013, 12:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The associated production of jets and vector bosons allows for stringent tests of perturbative QCD calculations and is sensitive to the possible presence of new physics beyond the Standard Model. Measurements of jet production rates in association with W, Z or photons, in proton-proton collisions at 7 TeV or 8 TeV center-of-mass energy is presented, using data collected with the CMS detector....
Pavel Starovoitov
(Deutsches Elektronen-Synchrotron (DE))
23/04/2013, 12:05
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Inclusive jet and dijet double-differential cross sections have been measured in proton-proton
collisions at a centre-of-mass energy of 2.76 and 7 TeV using the ATLAS detector. The cross sections were measured using jets clustered with the anti-kT algorithm. The data are compared to expectations based on next-to-leading order QCD calculations corrected for non-perturbative effects, as well...
Elif Asli Yetkin
(University of Iowa (US))
23/04/2013, 12:20
In this talk we will report from the two structures found in the J/psi phi decay channel, accessed through the exclusive B+ --> J/psi phi K+ decay. One of the structures confirms a previous observation by the CDF experiment, while the second structure has been observed by CMS for the first time. These contribute to the "systematic" studies of new structures in the search for new exotic...
James Alexander Kraus
(University of Mississippi (US))
23/04/2013, 12:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
We present results of diboson production studies with the D0 detector at sqrt(s) = 1.96 TeV, including measurements of the WW cross section in the lvl’v' channels and the ZZ cross section in the lll’l’ (l,l’ = e,mu) channels using data corresponding to integrated luminosity of 9.7 fb-1. We also present measurements of anomalous WWgamma and WWZ trilinear gauge boson couplings from WW and WZ...
Hoyoung Kang
(Seoul National University)
23/04/2013, 14:00
In Hall C at the Thomas Jefferson National Laboratory, the Spin Asymmetries of the Nucleon Experiment (SANE, E07-003) measured the spin asymmetries of the proton, using a polarized electron beam and a polarized ammonia target. By rotation of superconducting magnet about the target, parallel and near-perpendicular double spin asymmetries were measured at beam energies of $4.7$ and $5.9 GeV$....
Luis Alejandro Perez Perez
(INFN Sezione di Pisa)
23/04/2013, 14:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Searches for low mass CP-odd Higgs boson (A0) predicted
in non-minimal supersymmetric extensions of the Standard Model,
and for dark-sector Higgs-like and gauge bosons motivated by
recent astrophysical observations, have been performed at Babar
studying the radiative decays of the Y(nS) resonances, with n=1,2,3,
and multiparticle production in e+e- annihilations.
Stringent limits on the...
Benjamin Watt
(UCL)
23/04/2013, 14:00
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The effect of recent ATLAS inclusive- and di-jet results on the current standard PDF sets is investigated, and compared and contrasted to similar results from the Tevatron. We study the effect of the data using the parton reweighting technique. For ATLAS inclusive jets, there is good agreement across all values of x, and no significant pull is seen on the gluon. For dijets, both D0 and ATLAS...
Isabella Masina
23/04/2013, 14:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The measurements of the Higgs boson and top quark masses can be used to extrapolate the Standard Model Higgs potential at energies up to the Planck scale. Adopting a NNLO renormalization procedure, we: i) find that electroweak vacuum stability is at present allowed, discuss the associated theoretical and experimental errors and the prospects for its future tests; ii) determine the boundary...
Cyrille Marquet
23/04/2013, 14:20
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Within the Color Glass Condensate (CGC) framework, I will discuss particle production in the collision of a dilute projectile with a dense hadronic target. For years CGC studies focused on the dipole scattering amplitude, and it's evolution towards high energies or small x. One has now reached an accuracy sufficient to quantitatively describe single inclusive particle production in p+A type...
Vincent Andrieux
(CEA/IRFU, France)
23/04/2013, 14:20
New results on the double spin asymmetry $A_1$ and the spin-dependent structure function of the proton $g_1^p$ as a function of $x_{Bj}$ and $Q^2$ will be presented. They rely on the DIS data collected in 2011 by the COMPASS Collaboration with a polarised muon beam of 200 GeV and a polarised $NH_3$ target. The high energy of the beam allows $A_1$ measurements down to $x_{Bj}$ = 0.0025 for the...
Denis Bernard
(Laboratoire Leprince-Ringuet)
23/04/2013, 14:20
The B factories provide a unique playground for studying the properties of conventional and exotic charmonium states. We present recent results in initial state radiation and two-photon fusion, obtained using the full data set collected by the BaBar experiment.
Javier Llorente Merino
(Universidad Autonoma de Madrid (ES))
23/04/2013, 14:20
A measurement of jet shapes in t-tbar final states using data recorded by the ATLAS detector is presented. Samples of events with top-quark pairs are selected in both the semileptonic and dileptonic decay modes and the differential and integrated shapes of the b-quark jets resulting from the top-quark decays are compared with those of the light-quark jets from the hadronic W-boson decays W ->...
Ms
Claudia Bertella
(Centre National de la Recherche Scientifique (FR))
23/04/2013, 14:24
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Measurements of the top quark production cross sections in proton-proton collisions with the ATLAS detector at the Large
Hadron Collider are presented. The measurement require no, one or two electrons or muons in the final state (single
lepton, dilepton, hadronic channel).
In addition, the decay modes with tau leptons are tested (channels with tau leptons). The main focus are measurements...
Alberto Accardi
(Hampton U. and Jefferson Lab)
23/04/2013, 14:40
The Jefferson Lab Angular Momentum (JAM) collaboration is a
new initiative aimed at the study of the angular-momentum-dependent
structure of the nucleon. First results on the determination of
spin-dependent parton distribution functions from world data on
polarized deep-inelastic scattering will be presented and compared
with previous determinations from other groups. Different aspects...
Philip James Ilten
(University College Dublin (IE))
23/04/2013, 14:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Limits on the cross-section times branching fraction for Higgs particles, produced in pp collisions at sqrt(s) = 7 TeV, and decaying to two taus with pseudorapidities between 2 and 4.5, are presented.
The result is based on a dataset of 1.0 fb-1 collected by the LHCb detector. Model independent upper limits on neutral Higgs cross-section times branching fraction are set and are compared to...
Geert Jan Besjes
(Radboud University Nijmegen (NL))
23/04/2013, 14:40
Supersymmetry features a broad range of possible signatures at the LHC. If R-parity is conserved the production of squarks and gluinos is accompanied by events with hard jets, possibly leptons or photons and missing transverse momentum. Some Standard Model processes also mimic such events, which, due to their large cross sections, represent backgrounds that can fake or hide supersymmetry....
Maddalena Frosini
(Universita e INFN (IT))
23/04/2013, 14:40
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Studies of quarkonia production in the forward region provide important tests of NRQCD. The LHCb experiment has collected a dataset corresponding to an integrated luminosity of about 3 fb-l in
proton-proton collisions at sqrt(s)= 7 and 8 TeV. We present studies of the production and polarisation of the J/psi, psi(2S) and chi_c charmonium states as well as those of Upsilon and chi_b...
Dr
Sevda Esen
(University of Cincinnati)
23/04/2013, 14:40
The Belle experiment has recorded 121 fb-1 of data at the Y(5S)
resonance, making this the world's largest data sample at this energy.
As the Y(5S) decays to Bs(*)Bs(*) pairs, this large sample provides
a unique opportunity for detailed studies of Bs decays at an e+e-
machine. Here we report a recent measurement of Bs->Ds(*)Ds(*)
decays and a new measurment of Bs->Ds(*)h decays.
Jan Kieseler
(Deutsches Elektronen-Synchrotron (DE))
23/04/2013, 14:48
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Measurements of inclusive and differential top quark pair production cross section at 8 TeV are presented, performed using CMS data collected in 2012. The total cross section is measured in the lepton+jets and dilepton channels, including the tau-dilepton mode. DIfferential cross sections are measured as a function of various kinematic observables, including the transverse momentum and...
Panagiotis Katsas
(Deutsches Elektronen-Synchrotron (DE))
23/04/2013, 15:00
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Measurements of the pseudorapidity distribution of charged hadrons in pp collisions at 8 TeV are presented, and compared to the predictions of Monte Carlo models.
Luis Alejandro Perez Perez
(INFN Sezione di Pisa),
Luis Alejandro Perez Perez
(Sezione di Pisa (IT))
23/04/2013, 15:00
Although CP violation in the B-meson system has been well established
by the B factories, there has been no direct observation of time-reversal
violation in this system. Using 468 million B-Bbar pairs collected by the
BABAR detector at SLAC, we measure T-violating parameters in the time
evolution of neutral-B mesons by comparing the probabilities of B0 or
anti-B0 transforming into...
Adrian Perieanu
(Rheinisch-Westfaelische Tech. Hoch. (DE))
23/04/2013, 15:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Results are presented from CMS on searches for Higgs-like particles in models beyond the Standard Model and searches for rare or exotic decays of the 125 GeV particle. Light Higgses as predicted in the NMSSM models
are searched for. Decays of the 125 GeV Higgs-like particle into muons are explored. The most recent results will be presented.
Deepak Kar
(University of Glasgow (GB))
23/04/2013, 15:00
The transverse energy flow and charged track properties provide inside on the structure of the hadronic events, for soft collisions as well as events with a presence of hard scale. The observables studied include the transverse thrust, thrust minor and transverse sphericity, each defined using the momenta perpendicular to the beam direction of the final state charged particles. In addition to...
Sanghwa Park
(Seoul National University)
23/04/2013, 15:00
Measuring the flavor-separated quarks polarization is one of the primary goals in the PHENIX experiment at RHIC in order to understand the proton spin structure. The sea quark parton distriubution fuction (PDF) is not well known while the valence quark PDF is well constrained. The asymmetry of W production $A_{L}$ from polarized proton is sensitive to the helicity distribution of quarks and...
Dr
Marco Guzzi
(Desy Hamburg)
23/04/2013, 15:12
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The rate of the ttbar production at the LHC is large enough to make
thorough measurements of the differential cross section in terms
of the relevant kinematic final-state variables, i.e. transverse momentum $P_T$, rapidity $y$, invariant mass, etc..
The theoretical analysis of such differential distributions requires
knowledge of QCD corrections beyond the NLO as well as higher-order...
Dominik Duda
(Bergische Universitaet Wuppertal (DE))
23/04/2013, 15:20
The large centre-of-mass energy available at the proton-proton collider LHC allows for the copious production of top quark pairs in association with other final state particles at high transverse momentum. The ATLAS experiment has measured several final state observables that are sensitive to additional parton radiation in top anti-top quark final states. Examples are the multiplicity of jets...
Anastasia Grebenyuk
(Deutsches Elektronen-Synchrotron (DE))
23/04/2013, 15:20
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We suggest that, if current measurements of inclusive jet and leading track production for central rapidities at the LHC are extended to lower transverse momenta, one could define a visible cross section sensitive to the unitarity bound set by the recent determination of the inelastic proton-proton cross section.
Prof.
Bernd Surrow
(Temple University)
23/04/2013, 15:20
The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National
Laboratory is carrying out a spin physics program in high-energy polarized proton collisions
at $\sqrt{s}=200\,$GeV and $\sqrt{s}=500\,$GeV
to gain a deeper insight into the spin structure and
dynamics of the proton.
The collision of polarized protons at $\sqrt{s}=500\,$GeV opens a new era of spin-flavor...
Marco Agustoni
(Universitaet Bern (CH))
23/04/2013, 15:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Many supersymmetry models feature gauginos and also sleptons with masses less than a few hundred GeV. These can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents results from searches for gaugino and slepton pair production in final states with leptons.
Ruben Sandapen
(Université de Moncton)
23/04/2013, 15:25
We use new AdS/QCD Distribution Amplitudes (DAs), derived from the meson AdS/QCD light-front wave function, in order to investigate radiative B decays to light vector mesons. When computing the annihilation diagrams in B \to \rho + \gamma and the isospin asymmetry in B \to K* + \gamma, we find that the AdS/QCD DAs do not lead to the end-point divergences encountered with standard QCD Sum...
Juan Rojo Chacon
(CERN)
23/04/2013, 15:36
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We derive NNLO+NNLL theoretical predictions for top quark pair production based on all the available NNLO PDF sets, and compare them with the most precise LHC and Tevatron data. In this comparison we study in detail the PDF uncertainty and the scale, $m_t$ and $\alpha_s$ dependence of the theoretical predictions for each PDF set. Next, we exploit the observation that top quark pair production...
Kajari Mazumdar
(Tata Inst. of Fundamental Research (IN))
23/04/2013, 15:40
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Studies of the underlying event in p-p collisions at 0.9, 2.76, and 7 TeV are presented, using leading charged tracks at central rapidities, and the energy density measured at forward rapidities. The results are compared to model predictions, and provide constraints on the tuning of Monte Carlo parameters at the LHC.
Mr
Emanuele Roberto Nocera
(Università degli Studi di Milano & INFN Milano,Italy)
23/04/2013, 15:40
We discuss how a Monte Carlo set of polarized parton distributions, based on inclusive DIS data only, can be supplemented with the experimental information coming from other processes via Bayesian reweighting.
We briefly summarize the features of the reweighting technique and we use it to test the impact of open charm muoproduction and $W^\pm$ production data on a neural network, DIS-based,...
Peter Thomassen
(Rutgers, State Univ. of New Jersey (US))
23/04/2013, 15:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
In this talk, the latest results from CMS on searches for new physics with multiple leptons in the final state are presented using up to 20/fb of data from the 8 TeV LHC run of 2012. Interpretations of results in terms of RP conserving as well as violating models of supersymmetry are presented for weak and strong production mechanisms. For RP conserving models, both neutralinos and gravitinos...
Mr
Michal Deak
(IFIC/CSIC, Universitat de Valencia)
23/04/2013, 16:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We use the heavy quark impact factor at NLO order and multi-regge kinematic regime to calculate of single bottom production cross section at large rapidity at LHC energies.
Dr
Iain Bertram
(Lancaster University)
23/04/2013, 16:30
We present new and recent heavy-flavor results from the D0 Experiment, using the full ~10 fb-1 sample of ppbar collisions collected at sqrt(s) = 1.96 TeV, at the Tevatron collider.
The semileptonic mixing asymmetries in B^0 (a^d_sl) and B_s^0 (a^s_sl) decays are extracted independently, with data-driven methods used to correct for reconstruction asymmetries. Both adsl and assl are found to be...
Konstantinos Vellidis
(Fermilab)
23/04/2013, 16:30
We present measurements of the cross sections of prompt photon pair production and direct photon production in association with a heavy quark (b or c) jet in ppbar collisions at sqrt{s}=1.96 TeV.
The data samples for both results correspond
to the full data set collected with the CDF II detector.
Measurements are compared with the current state-of-the-art
theoretical predictions.
Mickey Chiu
(Brookhaven National Lab)
23/04/2013, 16:30
Determining the contribution of gluon spin to the proton's total spin is one of the crucial ingredients in resolving the proton spin puzzle. Hints from recent measurements of double longitudinal asymmetries ($A_{LL}$) from the Relativistic Heavy Ion Collider (RHIC) suggest $\Delta g$ is non-zero at moderate values of Bjorken $x \sim 10^{-2}$. In the PHENIX experiment at RHIC, we have a...
Loukas Gouskos
(University of Athens (GR))
23/04/2013, 16:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
In this talk, the latest results from CMS on direct stop or sbottom pair production are reviewed. We present searches preformed for different stop and sbottom decay modes using up to 20/fb of data from the 8 TeV LHC run of 2012.
Prof.
Jacques SOFFER
(Temple University, Philadelphia, PA USA)
23/04/2013, 16:30
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The theoretical foundations of the quantum statistical approach to parton distributions are reviewed together with the phenomenological motivations from a few specific features of Deep Inelastic Scattering data. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and automatically account for the flavor and helicity symmetry breaking of the sea. We...
Markus Diehl
(DESY)
23/04/2013, 16:50
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
I discuss the possible size and the observable consequences of interparton correlactions in multiple hard scattering processes.
Carl Gagliardi
(Texas A&M University)
23/04/2013, 16:50
One of the primary goals of the RHIC spin program is to determine the gluon polarization distribution within the proton. At leading order, pp collisions involve a mixture of quark-quark, quark-gluon, and gluon-gluon scattering. In RHIC kinematics, the quark-gluon and gluon-gluon contributions dominate, which makes RHIC an ideal tool to explore gluon polarization. The STAR experiment has...
Priscilla Pani
(NIKHEF (NL))
23/04/2013, 16:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Top or bottom squarks with masses less than a few hundred GeV can also give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk...
Dr
Hannu Paukkunen
(University of Jyväskylä, Finland)
23/04/2013, 16:54
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
In this talk, we discuss the compatibility of different deeply
inelastic neutrino-nucleus data sets and the universal nuclear
parton distribution functions (PDFs). This is an issue that has
lately been investigated by different groups but the conclusions
have been contradictory. While some studies have found a good overall
agreement between the nuclear PDFs and the neutrino data,...
Dr
Luis Silva
(LIP Lisbon)
23/04/2013, 17:10
In the context of the nucleon spin structure, the contribution from the gluons plays an important role. The so-called gluon polarisation can be determined in DIS through the Photon-Gluon Fusion (PGF) process. In the COMPASS experiment, data were collected with a naturally polarised 160 GeV/c muon beam, impinging on a polarised nucleon. Two analyses aiming at the extraction of the gluon...
Elena Romero Adam
(Universidad de Valencia (ES))
23/04/2013, 17:10
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent ATLAS results on inclusive searches for supersymmetric squarks and gluinos in events containing jets, missing transverse momentum with and without light leptons, taus or photons.
Emilia Lewandowska
(Institute of Nuclear Physics PAN)
23/04/2013, 17:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Double parton distributions (DPDs) are used in the QCD description of double parton scattering. The DPDs evolve with hard scales through relatively new QCD evolution equations and obey nontrivial sum rules: momentum and valence quark number sum rules. Based on a constructed numerical program, we present recent results on the QCD evolution of the DPDs. In particular, we discuss the problem how...
Michal Svatos
(Acad. of Sciences of the Czech Rep. (CZ))
23/04/2013, 17:10
Isolated prompt photons provide a direct probe of short-distance physics, complementary to that provided by measurements of jets or vector-bosons. The data are sensitive to the gluon density of the proton. The inclusive prompt photon cross sections have been measured over a wide range of transverse momenta; the diphoton cross section has also been measured as a function of diphoton mass,...
Vladimir Gligorov
(CERN)
23/04/2013, 17:10
We present the latest results concerning excited D(s) and B(s) mesons using data collected by the LHCb experiment in proton-proton collision at the LHC. High precision measurements of the masses and widths of the D*s1(2700), D*sJ(2860), B*, Bs1(5830) and B*s2(5840) states are reported. The observation of the new decay mode B*s2 -> B*+K- is also presented.
Karol Kovarik
(University of Karlsruhe)
23/04/2013, 17:18
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
A global analysis of the proton PDF requires a combination of DIS, DY,
and jet data. The flavor differentiation depends heavily on the DIS
data, much of which is measured on nuclear targets; hence the nuclear
PDFs (nPDFs) come into play. A global nPDF analysis finds tensions
between the nuclear correction factors in various data sets. We
explore possible sources of this tension, and...
Dr
Paolo Bartalini
(National Taiwan University (TW))
23/04/2013, 17:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
to be defined
Carolina Deluca
(NIKHEF (NL))
23/04/2013, 17:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Real and virtual production of third generation squarks via decay of a gluino can be significant if the mass of the gluino does not exceed the TeV scale. The talk presents recent ATLAS results from searches for...
Xin Shi
(National Taiwan University (TW))
23/04/2013, 17:30
Rare beauty decays are usually an excellent probe to the physics beyond the standard model. Especially those decays, that are proceed through flavor-changing neutral currents, can have the interference from new physics with the loop diagrams. Some of these decays are well predicted by the theory, such as B_s,d to mu+mu- branching fractions and the AFB of the B->K*mu+mu-, are the gold plate...
Mr
Grant Webb
(STAR Collaboration)
23/04/2013, 17:30
The STAR Spin program aims to measure the gluon helicity distribution $\Delta g(x)$ in the proton, which remains highly unconstrained at small momentum fractions $x < 0.05$. Dijet reconstruction in polarized proton collisions at $\sqrt s = 500$ GeV will extend these constraints by sampling lower $x$ gluons while also providing more precise information about the partonic kinematics. This...
Prof.
Barbara Badelek
(University of Warsaw, Poland)
23/04/2013, 17:42
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
A description of a nucleon structure in terms of partons demands
knowledge of parton momentum-, helicity- and transversity
distribution functions. COMPASS facility at CERN, with its high energy,
polarised muon beam, large polarised proton- and deuteron targets
and particle identification detectors, permits investigating the
(longitudinal and transverse) spin-dependent structure...
Dr
Murad Sarsour
(Georgia State University)
23/04/2013, 17:50
A major emphasis of the RHIC spin program at BNL is to understand the gluon spin contribution, Delta G, to the spin of the proton. The PHENIX experiment at RHIC probes Delta G, utilizing its highly segmented calorimeter, by measuring the double longitudinal spin asymmetry , A_LL, in the production of inclusive channels like pi0 and eta. pi0 data from runs 2005 and 2006 were included in a...
Miroslav Myska
(Acad. of Sciences of the Czech Rep. (CZ))
23/04/2013, 17:50
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The production of W bosons in association with two jets in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV has been investigated using data collected with the ATLAS detector. The fraction of events arising from double-parton scattering
has been measured through the pT balance between the two jets. The measurement provides new information on the proton structure and is...
Alastair Dewhurst
(STFC - Science & Technology Facilities Council (GB))
23/04/2013, 17:50
Mixing and CP violation is studied by ATLAS in the decay of the Bs meson to J/psi Phi, obnserved in the final state mu+mu-K+K-.
The different amplitudes contributing to the process are studied through the time dependence of the angular distribution.
Measurements of the average lifetime and lifetime difference between the two eigenstate BH and BL, and of the CP violating phase phi_s are...
Matthew King
(Kobe University (JP))
23/04/2013, 17:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
An extended QCD sector beyond the minimal supersymmetric standard model or the admission of R-parity violation introduces new signatures to the search for supersymmetry at the LHC. Strongly interacting resonances may decay to jets, sleptons may decay via lepton-flavour violating processes and lightest supersymmetric particles may decay into many leptons with or without missing transverse...
Eric Jansen
(University College London (UK))
23/04/2013, 17:50
The production of jets in association with a W or Z boson in proton-proton collisions at 7 TeV study multileg QCD diagrams. The cross section, differential in several kinematics variables,has been measured up to high jet multiplicities and compared to new higher-order QCD calculations. The ratio of (Z + a single jet)/(W + a single jet) can provide a very precise test of QCD and has also been...
Dr
Hannu Paukkunen
(University of Jyväskylä, Finland)
23/04/2013, 18:06
Future experiments
Talk in Parallel Session at DIS2013
I will present the current status of the nuclear parton distribution
functions highlighting the diverse possibilities that would be opened
by the LHeC.
Dr
Stephen Gliske
(Argonne National lab, for the STAR Collaboration)
23/04/2013, 18:10
The STAR endcap electromagnetic calorimeter (EEMC) was designed to allow measurement of cross sections and spin observables in the forward direction, $1 < \eta < 2$ and with the full azimuth. Using the EEMC to measure double longitudinal spin asymmetries in photonic channels---such as inclusive neutral pions, prompt photon, and prompt photon + jet---allows access to $\Delta G$ covering a lower...
Daniele Trocino
(Northeastern University (US))
23/04/2013, 18:10
We present studies of diboson production in pp collisions at 7 TeV and 8 TeV center-of-mass energy based on data recorded by the CMS detector at the LHC in 2011 and 2012. These include precise measurements of W and Z production in association with a photon, as well as WW, WZ, and ZZ production at the LHC. The results are interpreted in terms of constraints on anomalous triple gauge couplings.
Mr
Robert Schoefbeck
(Hephy Vienna),
Robert Schoefbeck
(Austrian Academy of Sciences (AT))
23/04/2013, 18:10
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
In this talk, the latest results from CMS on inclusive searches for squark and gluino production at the LHC are reviewed, including third generation signatures. A variety of complementary final state signatures and methods are presented using up to 20/fb of data from the 8 TeV LHC run of 2012.
Victor Fadin
(Budker Institute of Nuclear Physics Novosibirsk)
23/04/2013, 18:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
In the BFKL approach scattering amplitudes are given by convolutions of impact factors of colliding particles and Green functions of two reggeized gluons. A possibility to rearrange radiative corrections to scattering amplitudes between the impact factors
and the Green functions leads to an ambiguity of NLO BFKL kernels for equations of evolution of the Green functions with energy....
Semen Turchikhin
(M.V. Lomonosov Moscow State University (RU))
23/04/2013, 18:10
The decay of Bd mesons to the final state K*mu+mu- occurs via loop diagrams and is sensitive to physics beyond the Standard Model.
The first study performed by ATLAS, based on data collected in 2011 and including measurements of q-square dependence and angular distribution, will be discussed.
Wolfgang Schaefer
(Institute of Nuclear Physics PAN)
24/04/2013, 08:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Heavy nuclei at collider energies are a source of high-energy Weizsäcker-Williams photons. This photon flux may be utilized to study high-energy photon-nucleus interactions. We will first discuss the coherent diffractive production of heavy vector mesons on nuclear targets and show how it probes the unintegrated glue of the nucleus in the saturation domain. We present our calculations for...
Steffen Rocker
(KIT - Karlsruhe Institute of Technology (DE))
24/04/2013, 08:30
Measurements of single top quark production are presented, performed using CMS data collected in 2012 at centre-of-mass energies of 8 TeV. The cross sections for the electroweak production of single top quarks in the t-channel and in association with W-bosons is measured and the results are used to place constraints on the CKM matrix element Vtb. Measurements of top quark properties in single...
Levente Molnar
(Institut Pluridisciplinaire Hubert Curien (FR))
24/04/2013, 08:30
ALICE at LHC, collecting data in Pb-Pb, p-Pb and pp collisions, aims for the characterization of the QCD matter at high temperature and energy density.
While the first running period until 2017 can provide detailed description of
the global and bulk phenomena and a first set of results on rare probes of heavy-ion collisions, many important questions involving rare processes cannot be...
Aleko Khukhunaishvili
(Cornell University (US))
24/04/2013, 08:30
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We present selected measurements done with W and Z bosons performed with the CMS detector, based on samples of events collected during 2011 and 2012 physics runs. Measurements include W and Z inclusive cross sections, the lepton charge asymmetry in W events, and differential cross sections of Z and Drell-Yan production.
Dr
Franck Sabatie
(CEA Saclay)
24/04/2013, 08:50
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We systematically evaluate observables for hard exclusive electroproduction of real photons and compare them to experiment using a set of Generalized Parton Distributions (GPDs) whose parameters are constrained by Deeply Virtual Meson Production data, nucleon form factors and parton distributions. The Deeply Virtual Compton Scattering amplitudes are calculated to leading-twist accuracy and...
Marat Siddikov
(Universidad Santa Maria)
24/04/2013, 08:50
The analysis of deeply virtual meson production is extended to neutrino-production of the pseudo-Goldstone mesons (pions, kaons, eta-mesons) on nucleons, with the flavor content of the recoil baryon either remaining intact, or changing to a hyperon from the SU(3) octet. We rely on the SU(3) relations and express all the cross-sections in terms of the proton generalized parton distributions...
Dr
Mikhail Kalmykov
(II. Institut für Theoretische Physik Universität Hamburg Luruper Chaussee 149 22761 Hamburg Germany)
24/04/2013, 08:50
The value of electroweak contribution to the ratio between
pole and MSbar masses of top-quark are discussed. We argue that
for a Higgs boson mass M_H ~ 125 GeV,
the electroweak contribution are large and have opposite
sign relative to the QCD contribution
so that the total correction is small and approximately equal to 1 GeV.
This fact reduces the scheme dependence for any...
Francisco Campanario
(IFIC- University of Valencia)
24/04/2013, 08:50
We present recent results in precision multiboson (+jet) phenomenology at the LHC. Results for diboson (+ jet) and triboson (+jet) will be discussed focusing on the impact of the perturbative corrections on the expected phenomenology.
Ms
Katalin Nikolics
(Universite de Geneve (CH))
24/04/2013, 08:54
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Neutral current Drell Yan cross section is sensitive to the proton parton distribution
functions, in particular to u-bar quark density. The measurements
for two distinct kinematic regions, below the Z boson mass peak and above were performed by the ATLAS collaboration using 7 TeV pp collision data. The results are compared to NNLO QCD predictions corrected for NLO EW effects calculated...
Silvia Miglioranzi
(CERN, Aristotle Univ. of Thessaloniki (GR))
24/04/2013, 09:00
After successful LHC operation at the center-of-mass energy of 7 and 8
TeV in 2011 and 2012, plans are actively advancing for a series of
upgrades, culminating roughly 10 years from now in the high luminosity
LHC (HL-LHC) project, delivering of order five times the LHC nominal
instantaneous luminosity along with luminosity levelling. The final
goal is to extend the data set from about few...
Nelly Gogitidze
(DESY)
24/04/2013, 09:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Cross sections for elastic and proton dissociative photoproduction of J/ mesons are measured simultaneously in electron proton collisions at HERA using the H1 detector. Two data sets are analysed, one collected at the nominal ep centre-of-mass energy of
sqrt{s}\approx 320 GeV and having an integrated luminosity of 130 pb−1 and one recorded with a reduced proton beam energy resulting in...
Jakub Wagner
(Institute for Nuclear Studies)
24/04/2013, 09:10
We study timelike and spacelike virtual Compton scattering in the generalized Bjorken scaling regime at next to leading order in the strong coupling constant, in the medium energy range which will be studied intensely at JLab12 and in the COMPASS-II experiment at CERN. We show that the Born amplitudes get sizeable O(\alpha_s) corrections and, even at moderate energies, the gluonic...
Javier Brochero Cifuentes
(Universidad de Cantabria (ES))
24/04/2013, 09:10
Measurements of the top quark mass are presented, obtained from CMS data collected in 2011 and 2012 at a centre-of-mass energy of 7 TeV and 8 TeV. The mass of the top quark is measured using several methods. The results of the various channels are combined and compared to the world average. The dependence of the top-quark mass measurement on event kinematics is studied. The top mass and also...
Stefano Carrazza
(CERN)
24/04/2013, 09:18
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Electroweak corrections to hadron collider processes become
relevant at the level of precision reached by present-day LHC
experiments. I will provide a brief discussion of the impact of
electroweak corrections to parton distributions, concentrating on QED
corrections to parton evolution equations, and a preliminary
assessment of their impact.
Dr
Ronan Mcnulty
(University College Dublin (IE))
24/04/2013, 09:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Exclusive J/psi and psi(2S) vector meson production has been observed in the dimuon channel using the LHCb detector. The cross-section times branching fractions to two muons with pseudorapidities between 2.0 and 4.5 are measured and are found to be in good agreement with results from previous experiments and theoretical predictions. The J/psi photoproduction cross-section is reported as a...
Matteo Franchini
(Universita e INFN (IT))
24/04/2013, 09:30
Properties of the top quark are measured with the ATLAS detector using LHC proton-proton collisions data. Measurements of the top-quark mass and charge, as well as of the polarization of W bosons in top quark decays to probe the Wtb-vertex are presented.
A search for flavour changing neutral current processes in top quark decays is also presented.
In addition, measurements of the spin...
Samantha Katherine Dooling
(Deutsches Elektronen-Synchrotron (DE))
24/04/2013, 09:30
Comparisons of experimental data with theoretical predictions for
collider processes containing hadronic jets rely on shower Monte Carlo event generators to include corrections to perturbative
calculations from hadronization, parton showering, multiple parton collisions. We examine current treatments of these
corrections and propose alternative methods to take into...
Dr
Samuel Wallon
(LPT Orsay and UPMC University)
24/04/2013, 09:30
We derive an all order resummation formula for the deeply virtual Compton scattering amplitude, which takes into account soft-collinear gluon exchanges in the partonic (quark gluon) amplitude. We identify at each order of the perturbative series the diagrams responsible in a specific gauge to the leading contributions. An exponentiated expression results in a simple closed expression valid in...
Umberto Marconi
(Bologna)
24/04/2013, 09:30
The LHCb experiment is designed to perform high-precision measurements of CP violation and search for New Physics using the enormous flux of beauty and charmed hadrons produced at the LHC. The operation and the results obtained from the data collected in 2010 and 2011 demonstrate that the detector is robust and functioning very well. However, the limit of 1 fb–1 of data per year cannot be...
Juan Rojo Chacon
(CERN)
24/04/2013, 09:42
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We study at a quantitative level the impact of the uncertainties on the value of the W boson mass measured at hadron colliders due to the proton parton distribution functions (PDFs). The value of the W boson mass is extracted, by means of a template fit technique, from the lepton-pair transverse mass distribution measured in the charged current Drell-Yan process.. We conclude that PDF...
Efe Yazgan
(Ghent University (BE))
24/04/2013, 09:50
Measurements of several top-quark properties are presented, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV. The results include measurements of the top pair charge asymmetry, the W helicity in top decays, the top quark charge, and of the ttbar spin correlation and the search for anomalous couplings. The fraction of top quarks decaying into a...
Prof.
Konstantin Goulianos
(Rockefeller University (US))
24/04/2013, 09:50
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We would like to present results on diffractive and exclusive production from CDF experiment including new study of ppbar collisions at the Tevatron that have 2 or 4 charged hadrons in the central region with |eta|<1.3 with large rapidity gaps on either side. We use data taken at sqrt{s}=1960 and 900 GeV. This data provides a useful window on hadron spectroscopy, as well as providing...
Hannes Jung
(DESY),
Hannes Jung
(Deutsches Elektronen-Synchrotron (DE))
24/04/2013, 09:50
We investigate effects of small-x gluon coherence on final
states containing vector bosons and jets at the LHC. We use recent
results on transverse momentum dependent parton branching and
vector boson matrix elements, and present predictions for angular
correlations and pT imbalance distributions in W + 2 jets production.
We discuss implications of our results on studies of double...
Stephane Tourneur
(Ecole Polytechnique Federale de Lausanne (CH))
24/04/2013, 10:06
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We report measurements of Electroweak boson production in the forward region, using data collected at the LHCb experiment with a centre of mass energy of sqrt(s)=7 TeV with an integrated luminosity of up to 1.0 fb-1. W and Z bosons are reconstructed in leptonic decay channels, and their cross-sections determined using data-driven techniques. All results are compared to NNLO predictions.
Gustavo Gil Da Silveira
(Universite Catholique de Louvain (BE))
24/04/2013, 10:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We present results on exclusive production from CMS, including a first search for exclusive gammagamma->WW, and limits on anomalous quartic gauge couplings. We also present measurements of exclusive gammagamma->mumu and gammagamma->ee production, and the first limits on central exclusive production of photon pairs at 7 TeV.
James William Howarth
(University of Manchester (GB))
24/04/2013, 10:10
In proton-proton collisions at the LHC, pairs of top and anti-top quarks are expected to be
mostly produced through gluon fusion, in contrast to production at the Tevatron, where quark annihilation dominates.
Making use of the large number of top quark pairs, we present measurements of the spin correlation between top and
anti-top quarks as well as of the top-quark charge asymmetry which...
Katharina Schmidt
(Albert-Ludwigs-Universitaet Freiburg (DE))
24/04/2013, 10:10
Generalized parton distributions (GPDs) provide a dynamical picture of the nucleon. The exclusive production of $\rho^0$ mesons off a transversely polarised target is sensitive to the nucleon helicity-flip GPDs $E$ which are related to the total angular momentum of quarks and gluons.\\
In 2007 and 2010 the COMPASS experiment at CERN collected data by scattering a 160 GeV/c muon beam on a...
Andry Rakotozafindrabe
(CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR)),
Cynthia Hadjidakis
(Universite de Paris-Sud 11 (FR))
24/04/2013, 11:00
We outline the physics opportunities [1] which are offered by a next generation and multi-purpose fixed-target experiment exploiting the LHC beams extracted by a bent crystal. This mature extraction technique offers an ideal way to obtain a clean and very collimated high-energy beam, without altering at all the performance of the LHC [2,3,4]. The multi-TeV LHC beams grant the most energetic...
Eugenio Scapparone
(INFN-Bologna(IT))
24/04/2013, 11:00
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Ultra-relativistic heavy ions generate strong electromagnetic fields which offer
the possibility to study gamma-gamma and gamma-nucleus interactions at theLHC in the so called ultra-peripheral collisions (UPC). The J/psi photoproduction in UPC events in sensitive to the gluon distribution of the interacting nuclei, providing information on the nuclear gluon shadowing at Bjorken-x ranging...
Markus Diehl
(DESY)
24/04/2013, 11:00
I report on a recent fit of generalized parton distributions to the world data of electromagnetic nucleon form factors.
Laura Patel
(Georgia State University)
24/04/2013, 11:00
Due to their large mass, heavy quarks are produced in the earliest
stages of the collision and will, therefore, experience the full
evolution of the system. Leptons resulting from heavy flavor decay are
an important tool to probe the hot and dense matter created in nucleus-
nucleus collisions at the Relativistic Heavy Ion Collider (RHIC).
PHENIX is capable of measuring electrons...
Masahiro Kuze
24/04/2013, 11:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A search for events ep-> ep Z0 has been performed in ep collisions
at HERA using the ZEUS detector. The search is based on the entire HERA-I
and HERA-II data set, amounting to 0.49 fb-1 of integrated luminosity.
The Z0 was searched in the di-jet decay mode with elastic condition
defined by etamax < 3, where etamax
is defined as the pseudorapidity of the energy deposit in the...
Dr
Martin Hentschinski
(Brookhaven National Laboratory)
24/04/2013, 11:00
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We discuss recent work on the transverse momentum dependent sea quark density at small x and its application to Drell-Yan production at both forward and central rapidities.
Dr
Alexei Prokudin
(JLab)
24/04/2013, 11:20
We examine the QCD evolution of the helicity and transversity parton distribution functions when including also their dependence on transverse momentum. Using an appropriate definition of these polarized transverse momentum distributions (TMDs), we describe their dependence on the factorization scale and rapidity cutoff, which is essential for phenomenological applications.
Dr
Kikola Daniel
(Purdue University)
24/04/2013, 11:20
Relativistic heavy ion collisions provide a unique opportunity for studying Quark-Gluon Plasma (QGP), a new state of nuclear matter which properties are determined by quark and gluon degrees of freedom. Such a nuclear matter existed in the Early Universe, a few millionths of a second after the Big Bang. Heavy quarks are unique probes of the QGP properties because they are produced very early...
Davide Pagano
(Universite Catholique de Louvain (BE))
24/04/2013, 11:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
We present searches for massive top and bottom quark partners at CMS using data collected at sqrt(s)=7 and 8 TeV. Such partners can be seen in 4th generation models, or can be found in models predicting vector-like quarks to solve the Hierarchy problem and stabilize the Higgs mass. The searches span a range of final states, from multi-leptonic to entirely hadronic, and limits are set on mass...
Martin Hentschinski
(Brookhaven National Laboratory)
24/04/2013, 11:22
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Physical anomalous dimensions allow to describe the Q2 dependence of proton structure functions in a factorization scheme independent manner. We perform the first numerical implementation of these physical evolution kernels at both leading and next-to-leading order. A comparison to conventional DGLAP evolution based on factorization into coefficient and parton distribution functions is provided.
Antonio Cassese
(Universita e INFN (IT))
24/04/2013, 11:25
The rare decays K->pnn are excellent processes to make tests of new physics at
the highest scale complementary to LHC thanks to their theoretically cleaness.
The NA62 experiment at CERN SPS aims to collect of the order of 100 K+->p+nunu
events in two years of data taking, keeping the background at the level of 10%.
Part of the experimental apparatus has been commissioned during a...
Dr
Abhisek Sen
(University of Tennessee)
24/04/2013, 11:40
The measurement of quarkonia production in relativistic heavy ion collisions provides a powerful tool for studying the properties of hot and dense matter created in these collisions. To have a complete understanding, however, such measurements must cover a wide range of quarkonia states, collision energies and colliding species. The PHENIX detector recently collected high statistics data using...
Davide Pagano
(Universite Catholique de Louvain (BE))
24/04/2013, 11:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
In many models of physics beyond the Standard Model the coupling of new physics to third generation quarks is enhanced. We present a review of searches for heavy particles beyond the standard model decaying to final states with top and bottom quarks. This includes searches for heavy gauge bosons and excited states. Several final states originating from the top are considered and the event...
Mr
Maarten Buffing
(VU University Amsterdam / Nikhef)
24/04/2013, 11:40
We introduce transverse momentum dependent parton distribution functions (TMDs) for quarks and gluons with definite rank. The rank refers to the azimuthal dependence corresponding to the tensorial structure in transverse momenta multiplying universal functions only depending on x and pT^2. In this way only a finite number of functions of definite rank remains for a target with the number...
Hannes Jung
(Deutsches Elektronen-Synchrotron (DE))
24/04/2013, 11:44
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We present a determination of the transverse momentum dependent
(TMD) parton densities from HERA measurements.
The gluon and sea quark TMDs are obtained in the one-loop
approximation. The gluon density is also obtained in the all-loop,
small x improved, mode.
The determination of TMDs include also estimates on uncertainties.
Frédéric Fleuret
(LLR Ecole Polytechnique, IN2P3/CNRS)
24/04/2013, 11:50
Twenty five years ago, CERN pioneered the study of quarkonium production in heavy ion collisions at the SPS with the aim of characterizing the QGP phase transition and testing lattice QCD predictions. In 1997, the NA50 experiment observed an anomalous suppression of J/psi production in Pb+Pb collisions. Since then, these quarkonium studies have been extended to regimes of significantly higher...
Jeppe Andersen
(IPPP Durham)
24/04/2013, 12:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
The High Energy Jets (HEJ) framework provides an all-order, all-multiplicity description of jet production. It is built upon approximations to the hard-scattering matrix element which are derived from the High Energy limit, and as such contains the leading-logarithmic corrections in large invariant mass between partons. These corrections are especially important in regions where there is a...
Jaroslav Bielcik
(Czech Technical University (CZ))
24/04/2013, 12:00
The calculations of Quantum Chromodynamics on lattice showed that under conditions of high energy density or high temperature nuclear matter undergoes a phase transition from state of confined quarks and gluons to deconfined state, the Quark-Gluon Plasma (QGP).
Such conditions were present in first moments after the Big Bang
in the early universe and can be created in laboratory by colliding...
Ignazio Scimemi
(Universidad Complutense de Madrid (UCM))
24/04/2013, 12:00
As a product of the factorization theorem of DY processes one can derive the evolution of TMDPDF at NNLL. An implementation of the evolutor is found which overcomes some difficulties due to the presence of the Landau pole. Final results are compared with phenomenology. Future developments are also discussed.
Henri Paul Kowalski
(Deutsches Elektronen Synchrotron (DESY))
24/04/2013, 12:06
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We analyze, in leading and next to leading order of the BFKL equation,
the effects of the quantization of the singularities of the $j$-plane, t-channel partial waves due to the imposition of appropriate infrared and ultraviolet boundary conditions. We show that the intercepts, $\omega_n$ of the Regge poles, which contribute significantly to the gluon density in the kinematic region measured...
Etienne Burtin
(CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
24/04/2013, 12:15
A major part of the future COMPASS program will be dedicated to the investigation of the nucleon structure through Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP).
COMPASS will measure DVCS and DVMP reactions with a high intensity
muon beam of 160 GeV of opposite charge and polarization which will allow to access the Compton form factor related to the...
Antoni Szczurek
(Institute of Nuclear Physics)
24/04/2013, 14:00
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We calculate differential distributions for the $p p \to p p \gamma$ reaction at the LHC energy $\sqrt{s} = 14$~TeV.
We consider diffractive classical bremsstrahlung mechanisms including effects of non point-like nature of protons.
In addition, we take into account (vector meson)-pomeron, photon-pion
as well as photon-pomeron exchange processes
for the first time in the...
Cynthia Keppel
(Jefferson Lab)
24/04/2013, 14:00
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
While an impressive amount of high quality nucleon structure function data exists from hydrogen, deuterium, and other targets, the lack of a neutron target has made direct comparisons between proton and neutron structure nearly impossible at large x where nuclear effects become large. The behavior of the d quark as x approaches 1 is particularly sensitive to deuterium nuclear corrections. The...
Andrii Verbytskyi
24/04/2013, 14:00
Heavy Flavours
Talk in Parallel Session at DIS2013
The production of the excited charm mesons D_1(2420) and
D*_2(2460) in ep collisions
has been measured with the ZEUS detector at HERA using an integrated luminosity of 373 pb-1.
The masses of the neutral and charged states, the widths of the neutral
states, and the helicity parameter of D_1(2420)^{0} were determined and compared withother measurements and
with theoretical...
Katarzyna Wichmann
(DESY)
24/04/2013, 14:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A search for first generation leptoquarks was performed in
polarized electron-proton collider data
recorded with the ZEUS detector at HERA in the years 2003-2007.
They were analyzed for final states with an electron and jets or with
missing transverse momentum and jets and a search for resonance structures
or other deviations from the Standard Model predictions
in the spectra of the...
Antoni Szczurek
(Institute of Nuclear Physics)
24/04/2013, 14:20
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We discuss the diffractive dissociation of gluons into heavy quark pairs.
The particular mechanism is similar to the diffractive dissociation
of virtual photons into quarks, which drives diffractive deep inelastic
production of charm in the low-mass diffraction, or large $\beta$-region.
The amplitude for the $g p \to Q \bar Q p$ is derived in the impact
parameter and momentum space. The...
Ewald Paul
24/04/2013, 14:20
Heavy Flavours
Talk in Parallel Session at DIS2013
The production of D*, D+, D0, Ds and Lambda_c charm hadrons and
their antiparticles in ep scattering at HERA was studied with
the ZEUS detector using the full HERA II data set.
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 in the visible kinematic range.
Simone Zimmermann
(Universitaet Bonn (DE))
24/04/2013, 14:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Resonances decaying into a pair of particles are an obvious
place to look for phenomena beyond the Standard Model.
This talk summarizes recent results on searches for resonances in pairs of jets, lepton
pairs, leptons and missing transverse energy and pairs of photons. Various models
models are considered such the Z' and W', the Randall-Sundrum gravitons as
well as the ADD large extra...
Dr
Mher Aghasyan
(LNF, INFN)
24/04/2013, 14:20
Studies of single and double-spin asymmetries in pion electro-production in semi-inclusive deep-inelastic scattering of 5.8 GeV polarized electrons from unpolarized and longitudinally polarized targets at the Thomas Jefferson National Accelerator Facility using CLAS will be discussed. The dependence of these amplitudes on Bjorken x and on the pion transverse momentum has been extracted and is...
Harold E Jackson Jr
(Argonne National Laboratory)
24/04/2013, 14:25
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
In 2008 HERMES published the results of an ``isoscalar'' extraction
in leading logarithmic order (LO) in the strong coupling constant of
quantum chromodynamics of the momentum and helicity density distributions of the strange sea in the nucleon from the charged-kaon production in deep-inelastic scattering (DIS) on the deuteron (Phys. Lett. B666, 446 (2008). The shape of the momentum...
Oliver Bruening
(CERN)
24/04/2013, 14:30
The status of the LHeC accelerator proposal will be reviewed.
Anna Martin
(Universita e INFN (IT))
24/04/2013, 14:40
COMPASS, a fixed target experiment at the CERN SPS, is measuring the partonic structure of the nucleon since 2002. An important part of this program are the measurements of transverse spin effects in semi-inclusive deep inelastic scattering of high energy muons off transversely polarized deuteron and proton solid state targets. This talk is dedicated to the measurements of the Collins and...
Shima Shimizu
(Kobe University (JP))
24/04/2013, 14:40
Heavy Flavours
Talk in Parallel Session at DIS2013
A measurement of the flavour composition of dijet events produced in pp collisions at 7 TeV using the ATLAS detector is presented. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the
presence of bottom, charm or solely light flavour hadrons in the jet.
The results agree with the predictions of leading- and...
Mr
Peter Vladimir Loscutoff
(Lawrence Berkeley National Lab. (US))
24/04/2013, 14:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The study of electroweak boson pair production is a powerful
test of the spontaneously broken gauge symmetry of the Standard Model
(SM) and can be used to search for phenomena beyond the SM. Heavy
particles decaying to gauge boson pairs are predicted by many scenarios
of new physics, including Extra Dimensions, and Technicolor models. We
present generic searches for a heavy particle...
Cristiano Brenner Mariotto
(U)
24/04/2013, 14:40
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
In this work we study the prompt photon production in single and double diffractive processes considering the resolved Pomeron model. We estimate the rapidity and transverse momentum dependence of the cross section for the production of two photons and of a photon and a jet. We show that these processes are sensitive to the pomeron structure. In contrast with the dijet and heavy quark...
Eric Voutier
(LPSC/IN2P3/CNRS - UJF - INP)
24/04/2013, 14:45
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The partonic structure of hadrons as encoded via the so-called generalized parton distributions (GPD) can be accessed via deeply virtual Compton scattering (DVCS) experiments. Similarly to the scattering of light by a material, DVCS provides information about the dynamics and the spatial structure of hadrons. DVCS off nuclear targets allow to address the partonic structure of the nucleus...
Dr
Ruben Sandapen
(University of Moncton & Mount Allison University)
24/04/2013, 15:00
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We show that AdS/QCD generates predictions for the rate of diffractive ρ-meson electroproduction that are in agreement with data collected at the HERA electron- proton collider. We also predict the exclusive two pion spectra recently measured at HERA using AdS/QCD holographic light-front wave functions for the ρ-meson and its radial excitations.
Antoni Szczurek
(Institute of Nuclear Physics),
Rafal Maciula
(Institute of Nuclear Physics PAN)
24/04/2013, 15:00
Heavy Flavours
Talk in Parallel Session at DIS2013
We discuss production of two pairs of $c \bar c$ in proton-proton collisions at the LHC. Both double-parton scattering (DPS) and single-parton scattering (SPS) contributions are included in the analysis. Each step of DPS is calculated within $k_t$-factorization approach, i.e. effectively including next-to-leading order corrections. The conditions how to identify the DPS contribution are...
Preema Rennee Pais
(University of Massachusetts (US))
24/04/2013, 15:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Several extensions of the Standard Model predict the existence
of massive long-lived particles, some of these postulate the existence of
a hidden sector of particles. We report on searches for
weakly-interacting long-lived particles decaying to collimated
lepton-jets far away from the interaction point, and for production of
multicharged particles. The talk presents the final results...
Dr
Bakur Parsamyan
(University of Turin and INFN Turin (IT))
24/04/2013, 15:00
One of the important objectives of the COMPASS experiment (CERN, Geneva) is the exploration of the transverse spin structure of the nucleon via spin dependent azimuthal asymmetries in single-hadron production in deep inelastic scattering of polarized leptons off transversely polarized target. For this purpose a series of measurements were made in COMPASS, using 160 GeV/c longitudinally...
Dr
Eliezer Piasetzky
(Tel Aviv University)
24/04/2013, 15:10
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The deep inelastic scattering cross section for scattering from bound nucleons differs
from that of free nucleons. This phenomenon, first discovered 30 years ago, is known as the EMC effect and is still not fully understood. Recent analysis of world data showed that the strength of the EMC effect is linearly correlated with the relative amount of Two-Nucleon Short Range Correlated pairs...
Jan Olsson
(DESY)
24/04/2013, 15:20
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centre-of-mass energy sqrt(s) = 318 GeV where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account, resulting in an...
Christopher Braun
(Friedrich-Alexander-Univ. Erlangen (DE))
24/04/2013, 15:20
The parton distribution function h1 of a transversely polarized quark inside a transversely polarized nucleon, is chiral-odd and therefore not accessible in deep inelastic scattering. It can only be observed in semi-inclusive deep inelastic scattering (SIDIS) in combination with another chiral-odd function like e.g. the two-hadron interference fragmentation function (IFF) H1. The 160 GeV/c...
Nikolay ZOTOV
(SINP, Moscow State University)
24/04/2013, 15:20
Heavy Flavours
Talk in Parallel Session at DIS2013
The talk is based on the results of our publications [1]. First of all we show that
the contribution from double parton scattering to the inclusive production of heavy
meson pairs is comparable with the conventional single parton scattering mechanism
at the LHC energy. Then we focus on the problem of disentangling the single (SPS)
and double (DPS) parton scattering modes in the production...
elke-caroline Aschenauer
(BNL)
24/04/2013, 15:20
eRHIC is a proposed high luminosity, polarized Electron Ion Collider (EIC), which would make use of the existing RHIC infrastructure.
eRHIC is a triple-IP collider, with a dedicated eRHIC detector and the
possibility of using the two existing, but upgraded IP detectors PHENIX and STAR.
This presentation will describe the novel eRHIC machine, interaction region and dedicated detector...
Roger Caminal Armadans
(IFAE - Barcelona (ES))
24/04/2013, 15:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The compactification of the extra spatial dimensions in the
Arkani-Hamed, Dimopoulos, and Dvali model results in a Kaluza-Klein
tower of massive graviton modes. These graviton modes are produced in
association with a jet or a photon and do not interact with the
detectors, resulting in a monojet or a monophoton signature. This
channel is also sensitive to a large class of SUSY models. The...
Dr
Stephen Gliske
(Argonne National Lab)
24/04/2013, 15:40
Transverse Momentum Dependent (TMD) dihadron production, including vector meson production, allows access to various TMD distribution and fragmentation functions. Dihadron production is complementary to single hadron semi-inclusive DIS measurements, pairing the same distribution functions with different fragmentation functions. While dihadrons present unique measurement opportunities, the...
Andrew York
(University of Tennessee (US))
24/04/2013, 15:40
Heavy Flavours
Talk in Parallel Session at DIS2013
This talk presents quarkonium results, colllected in pp collisions at sqrt(s) = 7 TeV by the CMS collaboration, including the pT and rapidity differential prompt production cross-section of S-wave state quarkonia (J/psi, psi', Y(nS)), extending over a range of up to 100 GeV. We also present the B-hadron fraction in the charmonium system, differentially in pT.
Given its powerful Silicon...
Dr
Robert Ciesielski
(Rockefeller University (US))
24/04/2013, 15:40
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We present measurements of soft and hard diffraction at the LHC, including measurements of diffractive dijets at 7 TeV. We also show the first candidates for central dijet production with both leading protons tagged at the LHC, using the combined CMS and TOTEM detectors.
Jordan S Webster
(University of Chicago (US))
24/04/2013, 15:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Various extensions of the Standard Model predict the existence
of new types of quarks. We report on several search channels such as
vector-like quarks decaying to a Higgs boson and a top quark or to
a W boson and a b quark. The talk presents results from
searches for new resonances decaying to a top-antitop pair, including
the use of boosted top quark reconstruction techniques.
These...
Dr
Alexei Prokudin
(Jefferson Lab)
24/04/2013, 15:45
We consider the role process dependence in the Sivers effect
from analyzing the single transverse spin asymmetry for inclusive jet production in proton-proton collisions recently collected by AnDY experiment at RHIC, and the asymmetry data from semi-inclusive deep inelastic scattering experiments are presented. After carefully taking into account the initial-state and final-state...
Adrien Besse
(LPT Orsay)
24/04/2013, 16:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We discuss the high-energy exclusive electroproduction of rho
mesons, for both longitudinal and transversal polarizations.
The theoretical description of the cross-section is based on the
perturbative calculations of the transition gamma*L -> rhoL and gamma*T
-> rhoT, i.e. impact factors, within the collinear factorization of QCD.
We show how these impact factors can be related to...
Eleni Vryonidou
(U)
24/04/2013, 16:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The production of charm quark jets in association with electroweak gauge bosons at the LHC can be used as a tool to constrain quark parton distribution functions (PDFs). Motivated by measurements at the Tevatron and LHC, we calculate cross sections for W/Z + c, comparing these to W/Z + jet, for various PDF sets. The cross-section differences can be understood in terms of the different...
Stefano Melis
(University of Torino and INFN)
24/04/2013, 16:30
We present a global re-analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e^+ e^- to h1 h2 X processes, from the Belle Collaboration. Transversity and Collins functions are extracted simultaneously, in the framework of a new and revised global analysis in which a new parameterization...
Andre Mischke
(Utrecht University (NL))
24/04/2013, 16:30
Relativistic nucleus-nucleus collisions allow exploring the behaviour of strongly interacting matter at high temperatures and high energy densities, where a new phase of matter, the Quark-Gluon Plasma (QGP), is predicted to exist. In this phase colour confinement of quarks and gluons into hadrons should vanish.
Heavy-flavour particles, containing charm and beauty, are sensitive probes to...
Dr
Yuhong Zhang
(Thomas Jefferson National Accelerator Facility)
24/04/2013, 16:35
A polarized medium energy electron-ion collider (MEIC) is envisioned at Jefferson Lab as its future nuclear science program beyond the 12 GeV CEBAF fixed target program. Over the last three years, a conceptual design of MEIC has been successfully developed, and a comprehensive report summarizing the baseline and accelerator R&D progress has been released recently. The MEIC design studies have...
Isabella Garzia
(University of Ferrara)
24/04/2013, 16:45
Inclusive hadron production cross sections in e+e- collisions shed light
on fundamental questions of hadronization and fragmentation processes.
We present measurements of inclusive spectra of various light hadrons
produced in e+e- collisions at a center-of-mass energy of about 10.5 GeV. These results help test the scaling properties of the cross
sections by comparison with previous...
Diego Stocco
(Laboratoire de Physique Subatomique et des Technologies Associe)
24/04/2013, 16:50
The ALICE experiment is designed to study the properties of the high energy density medium formed in ultra-relativistic heavy-ion collisions. The measurement of open charm and beauty production in heavy ion collisions has an important role in the investigation, since it gives access to the mechanisms of heavy-quark propagation and energy loss in the hot and dense QCD matter. Heavy-flavour...
Alexander Huss
(University of Freiburg)
24/04/2013, 16:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
We present the calculation of the most important electroweak corrections to dijet production at the LHC and the Tevatron, comprising tree-level effects of O(\alpha_s\alpha,\alpha^2) and weak loop corrections of O(\alpha_s^2\alpha). Although suppressed by the small value of the coupling constant \alpha, these corrections can become large in the high-energy domain due to the appearance of...
Pawel Nadel-Turonski
(Jefferson Lab)
24/04/2013, 17:05
The Electron-Ion Collider (EIC) is envisioned as the next-generation US facility for exploring the strong interaction. The Medium-energy EIC (MEIC) is the first stage of the EIC at Jefferson Lab (JLab), designed for mapping the spin- and spatial structure of the quark and gluon sea in the nucleon, understanding the emergence of hadronic matter from color charge, and probing the gluon fields in...
Clemens Lange
(Deutsches Elektronen-Synchrotron (DE))
24/04/2013, 17:10
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Measurement of W+c production cross section has a unique sensitivity to the strange-quark density, which is poorly known at low x. W+b production, on the other hand, probes the b-quark production by higher order QCD processes. Cross sections are measured differentially as a function of jet multiplicity and transverse momentum of the leading b-jet, for the W+b measurement and as a function of...
Bernd Surrow
24/04/2013, 17:30
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National
Laboratory is carrying out a spin physics program in high-energy polarized proton collisions
at $\sqrt{s}=200\,$GeV and $\sqrt{s}=500\,$GeV
to gain a deeper insight into the spin structure and
dynamics of the proton.
The collision of polarized protons at $\sqrt{s}=500\,$GeV opens a new era of spin-flavor...
Achim Geiser
(DESY)
25/04/2013, 08:30
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections sigma_red^{c\bar{c}} for charm production are obtained in the kinematic range of photon virtuality 2.5<Q2<2000 GeV2 and Bjorken scaling variable 0.00003<x<0.05. The combination method accounts for the correlations of the...
David Ren-Hwa Yu
(Lawrence Berkeley National Lab. (US))
25/04/2013, 08:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Events containing several leptons are useful probes of new
phenomena due to the low background from Standard Model processes.
We look for anomalous production of prompt like-sign leptons or events with
three or more leptons, as well as search for excited leptons, heavy leptons
and heavy neutrinos. The searches use data recorded in 2012 at sqrt(s)=8 TeV
centre-of-mass energy by the ATLAS...
Oldrich Kepka
(Acad. of Sciences of the Czech Rep. (CZ))
25/04/2013, 08:30
Particle distributions sensitive to the underlying event in calorimeter jet events have been measured with the ATLAS detector at the LHC. Charged particle multiplicity, charged and inclusive sum transverse momentum (pT) densities and mean charged-particle pT in the regions of each event, azimuthally transverse to the hardest jet, are also presented.
The underlying event properties are...
Bakur Parsamyan
(Universita e INFN (IT))
25/04/2013, 08:30
The study of the spin structure of the nucleon and of the effects
due to the quarks transverse momentum are part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS.
The azimuthal modulations which appear in the cross-section of SIDIS off unpolarised targets give insight on the intrinsic momentum structure of the nucleon and on the possible correlation between...
Piotr Lebiedowicz
(Institute of Nuclear Physics PAN)
25/04/2013, 08:50
The amplitudes for $p p \to p p \pi^{0}$ process at high energy discussed given.
Both diffractive bremsstrahlung and diffractive $\pi^{0}$-rescattering
(Drell-Hiida-Deck (DHD) type model) as well as
photon-photon and photon-omega exchange mechanisms are
included in the calculation and discussed in detail.
Fairly large cross sections of the order of mb are predicted.
The corresponding...
Carl Vuosalo
(Ohio State University (US))
25/04/2013, 08:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
This talk will cover a wide range of new physics searches including many from the full dataset of 8 TeV pp collision from 2012. Included in the talk will be new physics searches in decays to multi-jet final states, leptons plus jets, and also searches for heavy long-lived charged particles.
Prof.
Jacques SOFFER
(Temple University, Philadelphia, PA USA)
25/04/2013, 08:50
The transverse single-spin asymmetry of neutrons produced at forward
rapidities in polarized pp collisions is calculated by means of an interesting interference mechanism and compared with a large effect
observed from recent measurements by the PHENIX experiment at RHIC.
Sergey Alekhin
25/04/2013, 08:55
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We present a determination of the running charm-quark mass in the MSbar scheme in framework of global analyses of the proton structure using recent HERA data of charm production cross section measurements. A crucial prerequisite for this task are QCD precision predictions to higher orders which require the choice of a scheme for the description of heavy-quark production in deep-inelastic...
Dr
Stefano Melis
(University of Torino and INFN)
25/04/2013, 09:10
Single spin asymmetries, AN, for inclusive particle production in pp collisions are considered within a generalized parton model with inclusion of spin and tranverse momentum effects.
We consider the potential role of the Sivers effect in AN, as extracted from a careful analysis of azimuthal asymmetries in SIDIS, and discuss its phenomenological consequences in connection with a recently...
Philipp Millet
(Rheinisch-Westfaelische Tech. Hoch. (DE))
25/04/2013, 09:10
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A search for new physics in final states with an electron or a muon and a low mass neutrino is presented based on the full 2012 data set at sqrt(s)=8TeV. The analysis searches for an excess of events above the SM expectation in the l+MET transverse mass spectrum. The results are interpreted in several different models, such as a new, heavy SM-like boson W' with and without interference with...
Prof.
Magno Machado
(IF-UFRGS)
25/04/2013, 09:15
In this contribution we investigate the photoproduction of massive gauge bosons, $W^{\pm}$ and $Z^0$, as part of relevant physics topics to be studied in the proposed electron-proton collider, the LHeC. The estimates for production cross sections and the number of events are presented. In addition, motivated by the intensive studies to test the deviations from the Standard Model at present and...
Dr
Aleksander Kusina
(Southern Methodist University)
25/04/2013, 09:20
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We analyze the impact of heavy flavors treatment in parton distribution
functions (PDFs) on measurable quantities like DIS structure functions.
We compare predictions obtained using ACOT scheme PDFs with different
number of active flavors and results of fix-flavor-number scheme.
We propose a correction factor that can be applied to calculations
carried in the fix-flavor-number scheme but...
Albert Knutsson
(University of Antwerp (BE))
25/04/2013, 09:30
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
We present results on forward and forward+central jet production, and on the properties of dijet events as a function of rapidity separation. The measurements are compared to model predictions to look for new effects in small-x interactions.
Steven Heppelmann
(Penn State University for the STAR Collaboration)
25/04/2013, 09:30
The STAR collaboration has collected two large data sets for measurement of forward π^0 transverse single spin asymmetries (SSA) in polarized pp collisions. Preliminary results and analysis progress will be presented for data from two RHIC runs, from RHIC Run 11 (2011) with energy √s=500 GeV and with luminosity of 22 pb-1 and from RHIC Run 12 (2012) with √s=200 GeV and with luminosity of 18...
Stefan Antonius Schmitz
(Rheinisch-Westfaelische Tech. Hoch. (DE))
25/04/2013, 09:30
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Additional heavy leptonic resonances (e.g. Z', W') are predicted by a number of new physics models. Models with extra dimensions include not only the possibility for resonant signatures like predicted in RS scenarios, but might also result in a non-resonant enhancement of high mass lepton pairs as suggested by the ADD model of large extra dimensions.
CMS has performed searches for both...
Nestor Armesto Perez
(Universidade de Santiago de Compostela (ES))
25/04/2013, 09:40
An overview of the possibilities for low-x physics at the LHeC will be reviewed. This will include inclusive, diffractive and final state observables.
Oleksandr Zenaiev
25/04/2013, 09:45
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Charm production in deep inelastic ep scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb-1.
Charm quarks were identified by reconstructing D+ mesons in the D+ --> K- pi+ pi+ decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5<Q2<1000 GeV2,...
Radek Zlebcik
25/04/2013, 09:50
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
The cross section of diffractive photoproduction processes e+p -> eXp is measured, where the system X contains at least 2 jets and the proton is tagged in the Very Forward Proton Spectrometer (VFPS) of the H1 detector. The measurement is performed for untagged photoproduction with Q2 <2 GeV2 in photon virtuality. The results are compared to next-to-leading order QCD calculations based on...
Dr
Elena Accomando
(University of Southampton)
25/04/2013, 09:50
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
Searches for extra heavy W' and Z'-bosons in the leptonic Drell-Yan channel at the LHC are favoured by present data. We focus on the common approximations used in theoretical and experimental analyses: neglecting interference and finite width effects. And present the implications of adopting such approximations on the data interpretation and the extraction of exclusion limits on W' and...
Olena Bachynska
(Deutsches Elektronen-Synchrotron (DESY)), Dr
Olena Bachynska
(DESY)
25/04/2013, 10:05
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Charm production has been measured with the ZEUS detector
in deep inelastic ep scattering at HERA.
The measurement is based on the full reconstruction of the decay chain
D*->D0pis, D0->Kpi and exploits the full HERA II statistics.
Differential cross sections have been measured.
The kinematic range is 1.5 GeV < pT(D*) < 10GeV, |eta(D*)| < 1.5,
5 < Q2 < 1000GeV2 and 0.02 < y <...
Bruce Mellado Garcia
(University of Wisconsin (US))
25/04/2013, 10:05
The prospects for the measurement of properties of the Higgs boson at the LHeC are reviewed. This includes isolating the Higgs boson with the bbar decay with a 1:1 signal-to-background ratio. This allows for the model independent study of the CP structure of the HWW coupling separately from that of the HZZ coupling. The complementarity of Higgs physics at the LHeC and the LHC will be discussed.
Sergey Podolsky
(UCL (Louvain-la-Neuve)),
Siarhei Padolski
(Universite Catholique de Louvain (BE))
25/04/2013, 10:10
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A precision measurement of the ratio RK of the rates of kaon leptonic decays
K+- --> e+- nu and K+- --> mu+- nu with the full minimum bias data sample
collected with low intensity 75 GeV/c beam by the NA62 experiment at CERN in
2007-2008 is reported. The result, obtained by analyzing ~150,000
reconstructed K+- --> e+- nu candidates with 11%
background contamination, has a record precision...
Bertrand Ducloue
(LPT Orsay)
25/04/2013, 10:10
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Mueller Navelet jets were proposed 25 years ago as a decisive test of BFKL dynamics at hadron colliders. We here present a next-to-leading BFKL study of the cross section and azimuthal decorrelation of these jets. This includes both next-to-leading corrections to the Green's function and next-to-leading corrections to the Mueller Navelet vertices. We compare our results with the same...
Ian Taylor
(Warwick University)
25/04/2013, 11:00
The nuSTORM facility will provide \nu_e and \nu_\mu beams from the
decay of 3.8GeV muons confined within a storage ring. A detector
placed approximately 1500m from the end of the decay straight,
combined with a near detector, can be used to make exquisitely
sensitive searches for sterile neutrinos. The instrumentation of the
ring, combined with the excellent knowledge of muon decay,...
Dr
Wilco den Dunnen
(University of Tübingen), Dr
Wilco den Dunnen
(VU University Amsterdam)
25/04/2013, 11:00
We present the di-photon distribution in the decay of an arbitrary spin-0 and spin-2 boson produced from gluon fusion, taking into account the fact that the gluons inside an unpolarized proton are linearly polarized to some extent. The gluon polarization brings about a difference in the transverse momentum distribution of positive and negative parity states. At the same time, it causes the...
Luca Barze
(CERN)
25/04/2013, 11:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
We present a theoretical overview of the present status and prospects for electroweak measurements at LHC, leading to precision tests of the standard model. The state of the art of Monte Carlo event generators is illustrated and special attention is paid to the interplay between QED and QCD, the measurement of the W mass and the effective weak mixing angle.
Regina Caputo
(Johannes-Gutenberg-Universitaet Mainz (DE))
25/04/2013, 11:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A measurement of the forward-backward asymmetry for the neutral current Drell Yan process is presented. The asymmetry is measured using dielectron and dimuon final states with sqrt(s) =7 TeV data. For the dielectron channel, the measurement includes electrons detected in the forward calorimeter which extends the covered phase space to the region less sensitive to the PDF uncertainties. The...
Yazid Delenda
(Université Hadj Lakhdar - Batna)
25/04/2013, 11:20
We address the problem of the resummation of Abelian clustering logarithms in QCD jet observables for jets defined using the kt, CA and SISCone algorithms. We specifically choose the jet mass distribution as an example and calculate up to O(alpha_s^4) clustering-logarithm coefficients to single log accuracy. We hence show that these logarithms exhibit a pattern of exponentiation and provide a...
Dr
Marco Guzzi
(Desy Hamburg)
25/04/2013, 11:25
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We determine the mass of the charm quark and study its effect
in the next-to-next-to-leading order ${\cal O}(\alpha_s^2)$
CTEQ global analysis of parton distribution functions (PDFs) of the proton. Fits are based on the general-mass variable flavor number scheme S-ACOT-$\chi$ for the treatment of heavy-quark contributions and include the recently published measurements of open charm...
Klaus Dehmelt
(Stony Brook University USA)
25/04/2013, 11:25
eRHIC is a proposed high luminosity, polarized Electron-Ion Collider (EIC), which would make use of the existing RHIC infrastructure. The eRHIC design is based on using one of the two RHIC hadron rings and a multi-pass Energy Recovery Linac (ERL). A polarized electron beam with an energy up to 30 GeV would collide with a number of ion species accelerated in the existing RHIC accelerator...
Fabio Dominguez
(IPhT Saclay)
25/04/2013, 11:40
We show explicitly how the linearly polarized gluon distributions appear naturally in high-energy dense-dilute collisions, where the small-x effects are important, and that under the proper kinematic conditions our results agree with the TMD-factorization formalism. In particular, the processes of dijet production in DIS and Drell-Yan in p-A collisions are studied and it is shown that they...
Breese Quinn
(University of Mississippi)
25/04/2013, 11:40
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
We present a measurement of the W boson mass using data corresponding to an integrated luminosity of 4.3 fb-1 collected with the D0 detector during Run 2 at the Fermilab Tevatron ppbar collider. With a sample of 1,677,394 W--> e nu candidate events, we measure M_W = 80.367 +/- 0.026 GeV. This result is combined with an earlier D0 result determined using an independent Run 2 data sample,...
Mathias Ritzmann
(IPhT CEA/Saclay)
25/04/2013, 11:40
I present recent developments in Vincia.
Vincia is a parton shower program, implemented as a plugin to Pythia 8, which emphasises efficient matching to fixed-order matrix elements and comprehensive estimates of uncertainties.
I discuss the extension of Vincia to hadronic initial states, a first step to LHC applications.
I also present the implementation of a shower evolving partons with...
Tzvetalina Stavreva
(LPSC)
25/04/2013, 11:50
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The associated production of a direct photon with a heavy quark provides us with the opportunity to test for and constrain the presence of intrinsic charm and bottom in the nucleon. We present comparisons of the theoretical predictions for this process with the initial measurements from D0 and CDF, as well as with the recently updated D0 measurements. Future predictions and possibilities for...
107.
Contribution of the twist-3 fragmentation function to single transverse-spin asymmetry in SIDIS
Koichi Kanazawa
(Niigata University)
25/04/2013, 12:00
We study the contribution of the twist-3 fragmentation function
to the single transverse-spin asymmetry in SIDIS within the framework of
the collinear factorization. Using the Ward-Takahashi identities in QCD,
we establish the collinear twist-3 formalism in the Feynman gauge to
calculate this contribution with manifest color gauge invariance. Then
we present a complete...
Lee Tomlinson
(University of Manchester (GB))
25/04/2013, 12:00
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
The presence of large logarithms in QCD corrections to observables spoils the validity of a calculation truncated at finite order and calls for an all-orders approach. The QT spectrum of massive lepton pairs, produced in hadron colliders by the Drell-Yan mechanism, has received a great deal of attention in electroweak phenomenology. We present and discuss a next-to-next-to-leading log (NNLL)...
Malin Sjodahl
(Lund University)
25/04/2013, 12:00
Both the higher energy and the initial state colored partons contribute to making exact calculations in QCD color space more important at the LHC than at its predecessors. This is applicable whether the method of assessing QCD is fixed order calculation, resummation, or parton showers.
In this talk I will discuss tools for tackling the problem of performing exact color summed calculations....
Mieczyslaw Witold Krasny
(Univ. P. et Marie Curie (Paris VI) (FR))
25/04/2013, 12:10
It is obvious that the DIS experimental programme needs a new experimental facility to survive. For such a facility, to be seriously considered, several conditions must be fulfilled:
1. It must address new physics questions (beyond those addressed at
HERA and TJNAF).
2. Its role must be widely recognized as essential for the model
independent interpretation of the LHC...
Elena Yatsenko
(Deutsches Elektronen-Synchrotron (DE))
25/04/2013, 12:20
Electroweak Physics and Beyond the Standard Model
Talk in Parallel Session at DIS2013
A measurement of angular correlations in Drell–Yan lepton pairs via the phi* observable is presented. This variable probes the same physics as the Z/gamma* boson transverse momentum (pT) with a better experimental resolution, especially for low transverse momenta. The measurement using phi* and the direct measurement of pT are compared to predictions based on QCD calculations and predictions...
Grigorios Chachamis
(IFIC (CSIC/UV) Valencia)
25/04/2013, 12:20
We will discuss briefly our recent studies on the non-forward BFKL equation in the adjoint representation for the N = 4 SYM theory at both LO and NLO accuracy using Monte Carlo techniques. We will then demonstrate the potential of these techniques for phenomenological studies at the LHC.
Cynthia Keppel
(Jefferson Lab),
Katerina Lipka
(Deutsches Elektronen-Synchrotron (DE)), Prof.
Pavel Nadolsky
(Southern Methodist University)
26/04/2013, 09:00
Halina Abramowicz
(Tel Aviv University (IL)),
Jonathan Jason Hollar
(Universite Catholique de Louvain (BE)),
Samuel Wallon
26/04/2013, 09:30
Alessandro Vicini
(Università degli Studi e INFN Milano (IT)),
Alexander Oh
(University of Manchester (GB)),
Markus Stoye
(CERN)
26/04/2013, 10:00
Andrea Banfi
(University of Freiburg), Dr
Bogdan Malaescu
(Univ. P. et Marie Curie (Paris VI) (FR)),
Claudia Glasman
(Universidad Autonoma de Madrid)
26/04/2013, 11:00
Antoni Szczurek
(Institute of Nuclear Physics),
Michel Sauter,
Sebastian Naumann-Emme
(Deutsches Elektronen-Synchrotron (DE))
26/04/2013, 11:30
Alessandro Bacchetta
(University of Pavia),
Francesca Giordano
(U),
Marcin Stolarski
(LIP Laboratorio de Instrumentacao e Fisica Experimental de Part),
Marco Contalbrigo
(Dipartimento di Fisica)
26/04/2013, 12:00
Dr
Armen Buniatyan
(DESY), Dr
Franck Sabatie
(CEA Saclay),
Nestor Armesto Perez
(Universidade de Santiago de Compostela (ES))
26/04/2013, 14:00
Rolf Heuer
(CERN)
26/04/2013, 14:50
Chris Quigg
(Fermi National Accelerator Lab. (US))
26/04/2013, 15:20
Cristinel Diaconu
(Centre National de la Recherche Scientifique (FR))
26/04/2013, 16:20
Ju-Jun Xie
(CHINESE ACADEMY OF SCIENCES, Lanzhou)
Future experiments
Talk in Parallel Session at DIS2013
There is a plan that the Institute of Modern
Physics (IMP)of CAS (Lanzhou) in China will
build a EIC under the High Intensity heavy
ion Accelerator Facility (HIAF). The EIC@HIAF
includes two stages: in the first stage we
will build 3 GeV (electron energy) x 12 GeV
(proton energy) EIC with luminosity up to
10^33 in 2019; In the second stage we will
build about 10~15 GeV (electron...
Mayya Golembiovskaya
(DESY)
Small-x, Diffraction and Vector Mesons
Talk in Parallel Session at DIS2013
Spin-density matrix elements (SDMEs) for exclusive ɸ meson leptoproduction were ex-tracted using the 27.6 GeV HERA longitudinally polarized lepton beam and longitudi-nally or transversely polarized or unpolarized hydrogen and deuterium gas targets. The Q2 and tʹ dependences of SDMEs determined in the kinematic region 1<Q2<7GeV2, tʹ>-0.4GeV2, W2>4GeV2, extracted from the whole HEMES data set,...
Jeppe Andersen
(IPPP Durham)
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
Using methods from effective field theory, we have recently developed a novel, systematic framework for the calculation of the cross-sections for electroweak gauge-boson production at small and very small transverse momentum q_T, in which large logarithms of the scale ratio M_V/q_T are resummed to all orders. This formalism is applied to the production of Higgs bosons in gluon fusion at the...
Klaus Rith
(University of Eralngen-Nürnberg)
Spin Physics
Talk in Parallel Session at DIS2013
Single-spin asymmetries were investigated in inclusive and semi-inclusive electroproduction of charged pions and kaons from a transversely polarized hydrogen target at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle $\psi$ about the beam direction between the 'upwards' target spin direction and the hadron production plane, the transverse hadron...
