Dr
Panos Kokkas
(University of Ioannina (GR))
18/07/2013, 09:00
QCD
Talk presentation
We present CMS results related to constraints on parton distribution functions and the strong coupling constant. Results include recent jet measurements performed with 2011 data taken at center-of-mass energy of 7 TeV and 2012 data taken at 8 TeV, including alphaS constraints from multijet events and PDF+alphaS constraints from jet production cross sections.
gauhar abbas
(IMSc Chennai, India)
18/07/2013, 09:15
QCD
Talk presentation
We determine the strong coupling constant $\alpha_s$ from the $\tau$ hadronic width using renormalization group summed expansion of the
QCD Adler function. The main theoretical uncertainty in the extraction of $\alpha_s$ is due to the way in which renormalization group invariance is implemented and the yet uncalculated higher order terms in the QCD perturbative series. We show that new...
Avtandyl Kharchilava
18/07/2013, 09:30
QCD
Talk presentation
We present measurements of three different multi-jet cross section ratios. These include the very first measurements of the new quantities $R_{\DeltaR}$ and $R_{\Delta\phi}$, and a measurement of $R_{3/2}$. The variable $R_{\DeltaR}$ measures the average number of neighboring jets for jets from an inclusive jet sample. The variable $R_{\Delta\phi}$ measures the fraction of the inclusive dijet...
Mr
Daniel Britzger
(DESY)
18/07/2013, 09:45
QCD
Talk presentation
New results on normalised inclusive jet, di-jet and trijet differential cross sections in neutral current deep-inelastic ep scattering (DIS) based on a regularised unfolding procedure are presented. Detector effects like acceptance and migrations as well as statistical correlations between the multi-jets and the inclusive DIS events are taken into account in this procedure. The DIS phase space...
Jean-Loic Kneur
(U)
18/07/2013, 10:00
QCD
Talk presentation
A variant of variationally optimized perturbation, incorporating renormalization group properties in a straightforward way, is used at three successive orders to calculate the nonperturbative ratio
$F_\pi/\Lambda$ of the pion decay constant and the basic QCD scale in the MSbar scheme. We demonstrate the good stability and (empirical) convergence properties of this modified perturbative series...
Lucy Anne Kogan
(University of Oxford (GB))
18/07/2013, 10:15
QCD
Talk presentation
Inclusive jet and dijet doubledifferential cross sections have been measured in protonproton collisions using the ATLAS detector. The cross sections were measured using jets clustered with the antikT algorithm. The data are compared to expectations based on nexttoleading order QCD calculations corrected for nonperturbative effects, as well as to nexttoleading order Monte Carlo...
Sanya Solodkov
(Institute for High Energy Physics (RU))
18/07/2013, 11:00
QCD
Talk presentation
Several aspects of the jet production in pp collisions have been measured by the ATLAS collaboration. Measurements of multijet systems, including heavy flavour production, with or without a veto on additional jets, probe QCD radiation effects. A measurement of the inclusive multiplicity ratio is sensitive to the strong coupling constant alpha_S and has reduced sensitivity to the uncertainties...
Mr
Henning Kirschenmann
(Hamburg University (DE))
18/07/2013, 11:15
QCD
Talk presentation
Calibration and reconstruction of jets critically rely on the performance of the calorimeters. Extending from out to $\eta < 5$, jets must critically rely on the interplay between forward calorimeters, central calorimeters and the tracker. The high pileup scenario poses further complications. These difficulties are overcome in CMS using the "particle flow approach". A summary of the...
Tiziano Peraro
(Max Planck Institute for Physics - Munich)
18/07/2013, 11:30
QCD
Talk presentation
I will present a novel approach for reduction of scattering amplitudes, based on multivariate polynomial division.
This technique extends the one-loop integrand reduction yielding the complete integrand decomposition for arbitrary amplitudes,regardless of the number of loops. It allows for the determination of the residue at any multi-particle cut, whose knowledge is a mandatory prerequisite...
Peter Loch
(University of Arizona (US))
18/07/2013, 11:45
QCD
Talk presentation
The internal structure of jets produced at the LHC is important both as a direct test of perturbative QCD and as a tool to identify boosted electroweakscale objects decaying to hadrons. The transverse energy distribution around the jet core has been measured, as well as the fragmentation of a jet into charged particles. Jet shapes, singlejet masses, and jet substructure have the potential to...
Alexander Schmidt
(University of Hamburg)
18/07/2013, 12:00
QCD
Talk presentation
Malin Sjodahl
(Lund University)
18/07/2013, 12:15
QCD
Talk presentation
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. I...
Michal Vajzer
(Acad. of Sciences of the Czech Rep. (CZ))
18/07/2013, 12:30
QCD
Talk presentation
Jets are collimated sprays of particles resulting from fragmentation of associated hard scattered partons. They are measured in different types of collisions at different energies to test perturbative Quantum Chromodynamic calculations and are used to study the hard scattering, fragmentation, hadronisation and other properties of partons. These properties studied in simple systems such as...
Nikolaos Kidonakis
(Kennesaw State University)
18/07/2013, 12:45
QCD
Talk presentation
I discuss the effectiveness of soft-gluon resummations in desribing higher-order corrections. I present a comparison of recent resummation approaches and their relative successes in approximating complete NNLO corrections. I also discuss fixed-order expansions through NNNLO and present some recent applications to QCD hard-scattering processes.
Zhiqing Philippe Zhang
(Universite de Paris-Sud 11 (FR))
18/07/2013, 14:30
QCD
Talk presentation
Inclusive e\pmp single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of \surds = 319GeV with a total integrated luminosity of 333.7 pb-1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential...
Katerina Lipka
(Deutsches Elektronen-Synchrotron (DE))
18/07/2013, 14:47
QCD
Talk presentation
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...
Massimo Corradi
(Universita e INFN (IT))
18/07/2013, 15:04
QCD
Talk presentation
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- π+π+ decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5 < Q2 < 1000 GeV2, 0.02...
Dr
Peter John Bussey
(University of Glasgow (GB))
18/07/2013, 15:21
QCD
Talk presentation
Isolated-photon+jet production in ep collisions at a centre-of-mass energy of 318 GeV has been measured with the ZEUS detector at HERA using an integrated luminosity of up to 300 pb-1.
Measurements of prompt-photon+jet cross sections are presented as functions of the photon transverse energy and pseudorapidity in a wide range of exchanged-photon virtuality.
In addition, differential...
Amanda Cooper-Sarkar,
Amanda Sarkar
(University of Oxford (GB))
18/07/2013, 15:38
QCD
Talk presentation
The Large Hadron Electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC through collisions with a new 60 GeV electron beam. This contribution summarises the detailed simulation studies on precision QCD topics included in the Conceptual Design Report, plus its relation with the LHC, and the outlook towards a Technical Design...
Andrey Sapronov
(Joint Inst. for Nuclear Research (RU))
18/07/2013, 16:30
QCD
Talk presentation
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...
Dr
Voica Ana Maria Radescu
(Deutsches Elektronen-Synchrotron (DE))
18/07/2013, 16:47
QCD
Talk presentation
Various measurements provided by the ATLAS collaboration have significant impact on parton density functions. Inclusive production of W and Z bosons have been analysed using an NNLO QCD fit and found to constraint the strangequark density at medium and low Bjorkenx. The inclusive jet production at different centreofmass energies, measured by ATLAS are used in an NLO QCD fit and show impact...
Charlotte Van Hulse,
charlotte Van Hulse
18/07/2013, 17:04
QCD
Talk presentation
HERMES had taken a wealth of deep-inelastic scattering (DIS) data using the 27.6 GeV polarized lepton beam at HERA and various pure gas targets, both unpolarized and polarized, which opened the door to several unique results. Among them are the first evidences for the naive-T-odd Sivers and Collins effects but also the recent first measurements of azimuthal modulations in the unpolarized...
Elena Zemlyanichkina
(Joint Inst. for Nuclear Research (RU))
18/07/2013, 17:26
QCD
Talk presentation
New results of the double spin asymmetry A1p and the spin-dependent structure function of the proton g1p as a function of $x_{Bj}$ and $Q^2$ will be presented. New COMPASS data on longitudinal polarized NH$_3$ target were collected during the year 2011 with beam of positive muons with energy E = 200 GeV}. It allows us to cover low $x$ region down to 0.025 in the range...
Nour Makke
(Universita e INFN (IT))
18/07/2013, 17:43
QCD
Talk presentation
The transversity parton distribution remains a poorly known cornerstone in the nucleon spin structure. While the Collins effect in spin asymmetries in Semi-Inclusive DIS (SIDIS) is one crucial tool to address the transversity function, the most promising alternative is the azimuthal asymmetry in SIDIS when a hadron pair is detected in the final state. In this case, the chiral-odd transversity...
Allen Caldwell
(Max Planck Institute),
Allen Christopher Caldwell
(Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)
19/07/2013, 09:00
QCD
Talk presentation
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...
Allen Caldwell
(Max Planck Institute),
Allen Christopher Caldwell
(Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)
19/07/2013, 09:15
QCD
Talk presentation
New measurements of the differential cross sections for neutral
current deep inelastic ep collisions up to Bjorken-x values equal to
one are presented. The measurements were performed using the data
collected with the ZEUS detector at HERA with sqrt(s) = 318 GeV and an
integrated luminosities of 142(187) pb-1 for e+p(e-p) collisions.
A new method was employed to reconstruct the kinematic...
Sanmay Ganguly
(Tata Inst. of Fundamental Research (IN))
19/07/2013, 09:40
QCD
Talk presentation
We present CMS results related to jet production cross sections, which pose a central test to perturbative QCD predictions. Results include recent jet, dijet, and multijet differential cross section measurements performed with 2011 data taken at center-of-mass energy of 7 TeV and 2012 data taken at 8 TeV.
Giovanni Ossola
(City University of New York (US))
19/07/2013, 09:55
QCD
Talk presentation
After reviewing the main features of the GoSam framework for automated one-loop calculations, we will show a selection recent phenomenological results obtained with it. In particular, we will present results for NLO QCD corrections to the production of Higgs boson in conjunction with jets at the LHC.
Lucia Hosekova
19/07/2013, 10:15
QCD
Talk presentation
Vector-boson fusion processes involving the scattering of vector bosons constitute an irreducible background to Higgs-boson production in association with two jets, as they share the same kinematical characteristics. It is therefore desirable
to obtain accurate theoretical predictions and error estimates for
these background processes with accuracy that goes beyond the leading order.
I show...
Jonathan Hollar
(Lawrence Livermore National Laboratory),
Jonathan Jason Hollar
(Universite Catholique de Louvain (BE))
19/07/2013, 11:00
QCD
Talk presentation
We present studies of exclusive WW production via photon-photon exchange, using data collected by the CMS detector at a center of mass energy of 7 TeV. The results are interpreted in terms of limits on anomalous quartic gauge couplings.
Mark Stockton
(McGill University (CA))
19/07/2013, 11:15
QCD
Talk presentation
Isolated prompt photons provide a direct probe of shortdistance physics, complementary to that provided by measurements of jets or vectorbosons. 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, total...
Pedro Vieira De Castro Ferreira Da Silva
(CERN)
19/07/2013, 11:30
QCD
Talk presentation
Alessandro Tricoli
(CERN)
19/07/2013, 11:45
QCD
Talk presentation
The production of the W and Z bosons is a standard candle process at the LHC. Precise total cross section measurements, in the fiducial region of the measurement and extrapolated to full phase space are presented. The differential Z/gamma∗ and the charge dependent W+ and W cross sections are provided in bins of boson rapidity and lepton pseudorapidity, respectively. The results are compared...
Alessandro Tricoli
(CERN)
19/07/2013, 11:55
QCD
Talk presentation
The production of jets in association with a W or Z boson in protonproton collisions at 7 TeV represent an important process to study QCD in a multiscale environment. The cross sections, differential in several kinematics variables, have been measured up to high jet multiplicities and compared to new higherorder QCD calculations. The ratio of (Z + a single jet)/(W + a single jet) can...
Bjoern Penning
(University of Chicago (US))
19/07/2013, 12:05
QCD
Talk presentation
Associated production of a W/Z bosons with jets are studied as a function of various kinematic observables. We present measurements of the ratios of cross sections, $\sigma(p\bar{p}\to Z+b~\text{jet})$/$\sigma(p\bar{p}\to Z+\text{jet})$, $\sigma(p\bar{p}\to Z+c~\text{jet})$/$\sigma(p\bar{p}\to Z+\text{jet})$ and $\sigma(p\bar{p}\to Z+c~\text{jet})$/$\sigma(p\bar{p}\to Z+b~\text{jet})$,...
Bjoern Penning
(University of Chicago (US))
19/07/2013, 12:15
QCD
Talk presentation
We present measurements of the differential cross section dsigma/dpT_gamma for the inclusive production of a photon in association with a b/c-quark jet. The results are based on data corresponding to an integrated luminosity of 8.7 fb^-1, recorded with the D0 detector at the Fermilab Tevatron ppbar collider at sqrt(s)=1.96 TeV. The measured cross sections are compared with next-to-leading...
Matthias Artur Weber
(Univ. of California Los Angeles (US))
19/07/2013, 12:25
QCD
Talk presentation
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 and 8 TeV center-of-mass energy are presented, using data collected with the CMS...
Grigorios Chachamis
(IFIC (CSIC/UV) Valencia)
19/07/2013, 12:40
QCD
Talk presentation
We will discuss the result with full mass dependence for the two-loop virtual QCD corrections to the W boson pair production in the quark-anti-quark annihilation channel. We will also report on our progress regarding the treatment of the double-real and virtual-real radiative corrections which are the other two necessary ingredients for a theoretical prediction of the total cross section to...
Dr
Marta Ruspa
(Universita e INFN (IT))
19/07/2013, 14:30
QCD
Talk presentation
Inclusive diffraction, DVCS and vector meson production at HERA
(agreed talk with H1/ZEUS collaborations)
Sergey Levonian
(Deutsches Elektronen-Synchrotron (DE))
19/07/2013, 14:50
QCD
Talk presentation
Recent H1 results on diffraction (agreed talk with H1/ZEUS collaborations)
Mariusz Sadzikowski
(Jagiellonian University)
19/07/2013, 15:05
QCD
Talk presentation
I discuss a twist decomposition of difractive structure functions in
the difractive deep inelastic scattering (DDIS) at HERA. At low
photon virtuality and at large energy the data exhibit a strong excess above the twist-two NLO DGLAP description. It is found, that complementing the DGLAP fit by twist 4 and 6 components of the
GBW saturation model leads to a good description of data.
In...
Mr
Philipp Roloff
(Deutsches Elektronen-Synchrotron (DESY)),
Philipp Roloff
(DESY), Dr
Philipp Roloff
(CERN)
19/07/2013, 15:20
QCD
Talk presentation
Differential inclusive-jet cross sections have been measured
in photoproduction for boson virtualities Q2 < 1 GeV2 with the ZEUS
detector at HERA using an integrated luminosity of 300 pb-1.
Jets were identified in the laboratory using the kt cluster algorithm
in the longitudinally inclusive mode.
Cross sections are presented as functions of the jet pseudorapidity, etajet,
and the...
Michel Sauter
19/07/2013, 15:35
QCD
Talk presentation
Recent H1 results on Heavy Flavour Photoproduction
(agreed talk with H1/ZEUS collaborations)
Lidia Goerlich
(Kraków Univ)
19/07/2013, 15:50
QCD
Talk presentation
Kenneth Oesterberg
(Helsinki Institute of Physics (FI)),
Kenneth Osterberg
(University of Helsinki)
19/07/2013, 16:10
QCD
Talk presentation
TOTEM is dedicated experiment at the LHC to the measurements of elastic, diffractive and other forward processes. Elastically and diffractively scattered protons are measured using silicon detectors in Roman Pots (RP) and charged particles by the T1 and T2 telescopes covering the pseudorapidity range 3.1 to 6.5.
TOTEM has measured the luminosity-independent total, elastic and inelastic...
Chiara Zampolli
(Universita e INFN (IT))
19/07/2013, 17:00
QCD
Talk presentation
ALICE is the LHC experiment dedicated to the study of ultra-relativistic Heavy-Ion collisions. Among the main characteristics of ALICE, its very low pT cut-off and material budget make it play an important role in the LHC pp physics program, especially in the soft QCD realm. In addition, pp collisions are of fundamental importance to provide input for Monte Carlo tuning, and to serve as a...
Marco Meissner
(Ruprecht-Karls-Universitaet Heidelberg (DE))
19/07/2013, 17:15
QCD
Talk presentation
Due to its unique pseudorapidity coverage and the possibility of extending measurements to low transverse momenta, LHCb provides important input to the understanding of particle production in a kinematical range where QCD models have large uncertainties. Measurements of charged, strange and charmed particle production and energy flow are performed in the approximate pseudorapidity range...
Claire Gwenlan
(University of Oxford (GB))
19/07/2013, 17:30
QCD
Talk presentation
Richard D. Field,
Richard Dryden Field
(University of Florida (US))
19/07/2013, 17:47
QCD
Talk presentation
At CDF we study charged particles production (pT > 0.5 GeV/c,
|eta| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV,
and 1.96 TeV. The 300 GeV and 900 GeV data are a result of the "Tevatron Energy Scan" which was performed just before the Tevatron was shut down.
We use the direction of the leading charged particle in each event, PTmax, to define three regions of eta-phi...
Ramandeep Kumar
(Panjab University (IN))
19/07/2013, 18:02
QCD
Talk presentation
Tomas Kasemets
(DESY)
19/07/2013, 18:19
QCD
Talk presentation
Double hard scattering in proton-proton collisions is described in terms of double parton distributions. We derive bounds on these distributions from their interpretation as probability densities, taking all possible spin correlations between two partons in an unpolarized proton into account. These bounds can be used to set limits on the effects of spin correlations in double hard scattering....
Dominik Werder
(Uppsala Universitet),
Dominik Werder
(Uppsala Universitet)
19/07/2013, 18:34
QCD
Talk presentation
The recent ATLAS data on dijet production with a veto on the additional interjet radiation is described by using the Banfi-Marchesini-Smye equation, which resums both the Sudakov logarithms as well as the non-global logarithms to leading log accuracy, to constrain the interjet energy flow. Without additional fit parameters, a good description of the data is obtained. Implications for BFKL...
Marek Schoenherr
(University of Durham)
19/07/2013, 18:49
QCD
Talk presentation
The merging of matrix elements and parton showers is an established calculational tool for the description of multi-jet final states at hadron colliders. These methods have recently been promoted to next-to-leading order accuracy in the description of hard well separated jets. This talk will introduce such a method and discuss its application to phenomenologically relevant signal and...
Zhenwei Yang
(Tsinghua University (CN)), Dr
Zhenwei Yang
(Tsinghua University (CN))
20/07/2013, 09:00
QCD
Talk presentation
Matthias Richter
(University of Oslo (NO))
20/07/2013, 09:20
QCD
Talk presentation
The study of heavy flavor production in proton-proton collisions is of particular interest for quantum chromodynamics (QCD), as charm and beauty quarks possess large masses and are thus mainly created in hard partonic scattering processes. Cross sections obtained from measurements for charm and beauty quarks allow to constrain theories and to provide important parameters for model...
Ilse Kratschmer
(Austrian Academy of Sciences (AT)),
Ilse Kratschmer
(Austrian Academy of Sciences (AT))
20/07/2013, 09:35
QCD
Talk presentation
Miriam Watson
(University of Birmingham (GB))
20/07/2013, 09:53
QCD
Talk presentation
Damir Becirevic
(CNRS et Universite Paris Sud),
Damir Becirevic
(Unknown)
20/07/2013, 10:11
QCD
Talk presentation
A long standing problem of theoretical estimate of the $J/\psi \to \eta_c \gamma$ decay amplitude has been solved recently by means of QCD on the latice. We describe and explain the progress and discuss the new results that are also a challenge to experimenters. We also discuss several other decay modes of charmonia, including the very first estimate of $\eta_c(2S)\to J/\psi \gamma$ that was...
Evgueni Goudzovski
(University of Birmingham)
20/07/2013, 11:00
QCD
Talk presentation
Recent measurements of the rare decay K+- --> pi+- gamma gamma at the NA48/2 and NA62 experiments are presented, including model-independent spectrum measurements and fits to the Chiral Perturbation Theory description. Precision measurements of the form factors and branching ratios of the K+- --> pi+ pi- e+- nu and K+- --> pi0 pi0 e+- nu decays at the NA48/2 experiment are also presented.
Dmitri Melikhov
(M. V. Lomonosov State University),
Dmitri Melikhov
(HEPHY)
20/07/2013, 11:20
QCD
Talk presentation
Making use of dispersive QCD sum rules, we analyze the pseudoscalar meson–photon transition form factors. We show that most of the existing measurements – the BaBar results for eta, eta’, and eta_c and the Belle results for pi^0 – are well compatible with each other and with the saturation predicted by pQCD factorization theorems and give a hint that the saturation is effective already at...
Min-Zu Wang
(Physics Department-National Taiwan University (NTU)-Unknown), Prof.
Min-Zu Wang
(National Taiwan Univ.)
20/07/2013, 11:35
QCD
Talk presentation
Bill Gary
(University of California Riverside (US))
20/07/2013, 12:00
QCD
Talk presentation
Dr
Nicolas Arnaud
(LAL (CNRS-IN2P3))
20/07/2013, 12:15
QCD
Talk presentation
Andrej Liptaj
(Slovak Academy of Sciences (SK))
20/07/2013, 12:30
QCD
Talk presentation
Covariant quark model is an ambitious model which is, inter alia, well suited for description of hadron decays. The model with its main features will be presented and then applied to describe some exclusive decays of the B_s meson. Results will be discussed in comparison with experimental data and other models.
Caterina Bloise
(Istituto Nazionale Fisica Nucleare (IT)),
Caterina Bloise
(Laboratori Nazionali di Frascati (LNF))
20/07/2013, 12:45
QCD
Talk presentation
The V-->Pgamma Dalitz decays, associated to internal conversion
of the photon into a lepton pair, are not well described by the
Vector Meson Dominance (VMD) models, as in the case of the
process omega --> pi0 mu+ mu-, measured by the NA60 collaboration.
The only existing data on phi --> eta e+ e- come from the SND
experiment, which has measured the Mee invariant mass distribution...
