Conveners
WG4: QCD and Hadronic Final States
- Daniel Britzger (Deutsches Elektronen-Synchrotron (DE))
- Vladimir Braun (University of Regensburg)
- Konstantinos Kousouris (CERN)
WG4: QCD and Hadronic Final States
- Vladimir Braun (University of Regensburg)
- Daniel Britzger (Deutsches Elektronen-Synchrotron (DE))
- Konstantinos Kousouris (CERN)
WG4: QCD and Hadronic Final States
- Vladimir Braun (University of Regensburg)
- Daniel Britzger (Deutsches Elektronen-Synchrotron (DE))
- Konstantinos Kousouris (CERN)
Gianluigi Cibinetto
(INFN Ferrara)
29/04/2014, 09:05
WG4: QCD and Hadronic Final States
Oral presentation
The BABAR Collaboration has an intensive program studying hadronic
cross sections at low-energy e+e- annihilations, accessible via initial-state radiation.
These measurements allow significant improvements in the precision of the predicted
value of the muon anomalous magnetic moment. We report here the results of
recent studies on a number of final states, as e+e- -> K+K-, e+e- -> K0S...
Gagik Vardanyan
(ANSL (Yerevan Physics Institute) (AM))
29/04/2014, 09:25
WG4: QCD and Hadronic Final States
Oral presentation
Measurements of jet production are sensitive to the strong coupling constant, next-to-leading order perturbative calculations and parton distribution functions. The measurements are obtained using data corresponding to an integrated luminosity of 4.5 fb −1, recorded by the ATLAS detector in 2011. Cross sections are measured up to 5 TeV dijet mass using jets reconstructed with the anti-kt...
Dr
Panos Kokkas
(University of Ioannina (GR))
29/04/2014, 09:45
WG4: QCD and Hadronic Final States
Oral 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, multijet differential cross section and hadronic event shape measurements performed with 2011 data taken at center-of-mass energy of 7 TeV and 2012 data taken at 8 TeV.
Pawel Sopicki
(IFJ PAN)
29/04/2014, 10:05
WG4: QCD and Hadronic Final States
Oral presentation
Signals of QCD instanton-induced processes are searched for in
deep-inelastic scattering (DIS) at the electron-proton collider HERA
in the kinematic region defined by the Bjorken-scaling variable x >
10$^{-3}$, the inelasticity 0.2< y < 0.7 and the photon virtuality
150 < Q$^{2}$ < 15000 GeV$^{2}$. The search is performed using H1
data corresponding to an integrated...
Oleg Kuprash
(DESY)
29/04/2014, 10:50
WG4: QCD and Hadronic Final States
Oral presentation
The photoproduction of isolated photons, both inclusive and
together with a jet, has been measured with the ZEUS detector at HERA
using an integrated luminosity of $374\, \mathrm{pb}^{-1}$.
Differential cross sections are presented in the isolated-photon
transverse-energy and pseudorapidity ranges $6 < E_T^{\gamma} <
15$ GeV and $-0.7 < \eta^{\gamma} < 0.9$, and for jet
transverse-energy...
Oleg Kuprash
(DESY)
29/04/2014, 11:10
WG4: QCD and Hadronic Final States
Oral presentation
The ZEUS Collaboration present further measurements of prompt photons produced with jets in photoproduction, studying a variety of kinematic variables that are sensitive to different aspects of the event dynamics. Cross sections are given in terms of the collinearity of the photon and the jet, the fraction of the proton energy involved in the interaction, and the pseudorapidity difference...
112.
Measurement of photon and photon+jet production cross sections at 7 TeV and constraints to PDFs
Josu Cantero Garcia
(Universidad Autonoma de Madrid (ES))
29/04/2014, 11:30
WG4: QCD and Hadronic Final States
Oral presentation
Measurement of the inclusive photon production performed by the ATLAS collaboration
using 4.6 fb-1 of sqrt(s)=7 TeV collision data is reported. Comparisons to the data of next-to-leading order QCD calculations MCFM and JetPhox with different PDFs are presented. The theoretical uncertainties, including scale, strong coupling, and PDF uncertainties are evaluated. The compatibility between data...
Jan Olsson
29/04/2014, 11:50
WG4: QCD and Hadronic Final States
Oral presentation
Measurements of the normalised cross sections for the production of
photons and neutrons at very small angles with respect to the proton
beam direction in deep-inelastic positron proton scattering at HERA
are presented as a function of the variable Feynman-x. The data are
taken with the H1 detector in the years 2006 and 2007 and correspond
to an integrated luminosity of 126 pb$^{-1}$. The...
Lorenzo Bellagamba
(Universita e INFN (IT))
29/04/2014, 14:00
WG4: QCD and Hadronic Final States
Oral presentation
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...
Homero Martinez Bruzual
(Universite de Paris-Sud 11 (FR))
29/04/2014, 14:20
WG4: QCD and Hadronic Final States
Oral presentation
Measurement of the transverse momentum of the Z boson performed by the ATLAS collaboration is
reported for sqrt(s) = 7 TeV. The measurement is sensitive to soft resummation
effects for small momentum transfers and to multiple hard jet
emissions for large momentum transfers, probing QCD in a unique
way. The data are used to tune NLO plus parton shower Monte Carlo simulations.
Mr
Kadir Ocalan
(Middle East Technical University (TR))
29/04/2014, 14:40
WG4: QCD and Hadronic Final States
Oral presentation
The production cross section of highly boosted vector bosons (V = W, Z or γ) recoiling against jets is studied, with CMS data, differentially as function of the transverse momentum and angular correlations of the final state particles. The measurements are confronted with different state-of-the-art theory predictions that include next-to-leading order calculations and matrix-element plus...
Marek Sirendi
(University of Cambridge (GB))
29/04/2014, 15:00
WG4: QCD and Hadronic Final States
Oral presentation
A measurement of the Z(→μ+μ−)+jet production cross-section in pp collisions at a centre-of-mass energy s√=7 TeV is presented. The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction. We also report about the observation of associated production of a Z boson with a D meson
Dr
Paul Michael Szczypka
(Ecole Polytechnique Federale de Lausanne (CH))
29/04/2014, 15:20
WG4: QCD and Hadronic Final States
Oral presentation
Charged particle multiplicities are studied in proton-proton collisions in the forward region at a centre-of-mass energy of sqrt(s) = 7 TeV with data collected in 2010 by the LHCb experiment. The forward spectrometer allows access to a kinematic range of 2.0 < eta < 4.8 in pseudorapidity, momenta down to 2 GeV/c and transverse momenta down to 0.2 GeV/c. The results are presented as functions...
Antoni Szczurek
(Institute of Nuclear Physics),
Rafal Maciula
(Institute of Nuclear Physics PAN)
29/04/2014, 16:10
WG4: QCD and Hadronic Final States
Oral presentation
We compare results of exact calculations of single-parton scattering (SPS)
and double-parton scattering (DPS) for production of
$c \bar c c \bar c$ and for $D-D$ meson correlations [1]. Each step of DPS is
calculated within $k_t$-factorization approach, i.e. effectively including next-to-leading order corrections.
The SPS calculations are performed in collinear approximation
with exact...
Hannah Ruth Arnold
(Albert-Ludwigs-Universitaet Freiburg (DE))
29/04/2014, 16:30
WG4: QCD and Hadronic Final States
Oral presentation
We present evidence of associated vector boson+prompt J/psi production and measure its production rate. This is a key observable to further the understanding of quarkonium production mechanisms. We estimate the relative contributions to the signal from single and double parton scattering and discuss possible implications of this novel final state for study of multiple parton interactions....
Rebecca Thalatta Chislett
(University of London (GB))
29/04/2014, 16:50
WG4: QCD and Hadronic Final States
Oral presentation
The identification and study of jets originated from the hadronic decays of massive particles, like vector bosons or top quark provide a direct test of QCD calculations of gluon and quark radiation and validate novel techniques of jet shapes and jet substructure for reducing the sensitivity to soft QCD and to multiple proton-proton collisions. A measurement of jet shapes in t-tbar final states...
Milena Hristova Misheva
(Joint Inst. for Nuclear Research (RU))
29/04/2014, 17:10
WG4: QCD and Hadronic Final States
Oral presentation
The NA48/2 Collaboration at CERN has accumulated unprecedented
statistics of rare kaon decays in the Ke4 modes Ke4(+-) to pi+ pi- e nu
and Ke4(00) to pi0 pi0 e nu with ~one percent background contamination.
The detailed study of form factors is sensitive to small isospin symmetry
breaking effects. This brings new inputs to low energy QCD description
and crucial tests of predictions from...
Plamen Rumenov Petrov
(Universite Catholique de Louvain (UCL) (BE))
29/04/2014, 17:30
WG4: QCD and Hadronic Final States
Oral presentation
New final results from an analysis of about 400 K+- --> pi+- gamma gamma rare decay candidates collected by the NA48/2 and NA62 experiments at CERN during low intensity runs with minimum bias trigger configurations are presented. The results include a model-independent decay rate measurement and fits to Chiral Perturbation Theory (ChPT) description. The data support the ChPT prediction for a...
Dr
Hannu Paukkunen
(University of Jyväskylä)
01/05/2014, 09:00
WG4: QCD and Hadronic Final States
Oral presentation
We will discuss the inclusive high-pT charged particle production in proton-proton
and proton-antiproton collisions with a special emphasis on the recent LHC and
Tevatron measurements. The experimental data are compared to the NLO perturbative
QCD calculations employing various sets of parton-to-hadron fragmentation functions.
Most of the theoretical predictions are found to disastrously...
Mr
Medley Jack
(University of Edinburgh)
01/05/2014, 09:20
WG4: QCD and Hadronic Final States
Oral presentation
In this talk I will discuss recent developments in the High Energy Jets (HEJ) description of multi-jet events. This provides an all-order description of wide-angle QCD radiation. After discussing recent developments and extensions of the formalism, I will discuss new predictions for Higgs plus jets and Z plus jets. I will also discuss comparisons with experimental data and other Monte Carlo...
Hans Van Haevermaet
(University of Antwerp (BE))
01/05/2014, 09:40
WG4: QCD and Hadronic Final States
Oral presentation
In the forthcoming high-luminosity phase at the LHC, many of the most interesting measurements for precision QCD studies are hampered by conditions of large pileup, particularly at not very high transverse momenta. We study observables based on measuring ratios of color-singlet currents via Higgs boson and Drell-Yan production, which may be accessed also at large pileup, and used for an...
Dr
Krzysztof Kutak
(Instytut Fizyki Jadrowej Polskiej Akademii Nauk)
01/05/2014, 10:00
WG4: QCD and Hadronic Final States
Oral presentation
The results for azimuthal decorelations in production of forward and central jets in collision p+p and p+Pb are going to be presented. The considered cross section is obtained within framework of high energy factorization and makes use of gluon density obtained from BK equation extended to account for corrections of higher order.
Dr
Alexander Thomas Goritschnig
(University of Graz)
01/05/2014, 11:10
WG4: QCD and Hadronic Final States
Oral presentation
We study the photoproduction of J/\Psi mesons off a proton in the kinematical regime of large energies and scattering angles within the framework of perturbative QCD. The heavy charm-quark mass is providing the relevant hard scale in the process. In particular, it is the so-called hard scattering approach which is taken as theoretical basis for our investigations. There the hadrons are...
Dr
Yogesh Kumar
(Department of Physics and Astrophysics)
01/05/2014, 11:30
WG4: QCD and Hadronic Final States
Oral presentation
We extend to investigate the evolution of free energy and direct photon production from quark-gluon plasma (QGP) considering finite chemical potential. The evolution of QGP formation at the chemical potential is done through finite value of quark mass.The evolution rate is found to be decreasing with chemical potential. We further study the direct photon emission from fireball of such QGP and...
Jean-Philippe Lansberg
(IPN Orsay, Paris Sud U. / IN2P3-CNRS)
01/05/2014, 11:50
WG4: QCD and Hadronic Final States
Oral presentation
In this talk, I discuss the growing interest to measure associated-quarkonium production in a number of channels at the LHC. Whereas back-to-back production of quarkonium + isolated photon provides a unique way to extract gluon TMDs [1], observables such as quarkonium + W/Z can be of great help to better understand the quarkonium production mechanism as well as to shed light on double-parton...
