Conveners
WG4: QCD and HFS: Hadron production // Jet physics, part #1
- Andrea Banfi (University of Sussex)
- Bogdan Malaescu (Univ. P. et Marie Curie (Paris VI) (FR))
- Claudia Glasman (Universidad Autonoma de Madrid)
WG4: QCD and HFS: Jet physics part #2 // Photon and boson+jet production
- Andrea Banfi (University of Sussex)
- Bogdan Malaescu (Univ. P. et Marie Curie (Paris VI) (FR))
- Claudia Glasman (Universidad Autonoma de Madrid)
WG4: QCD and HFS: WG4.3
- Claudia Glasman (Universidad Autonoma de Madrid)
- Andrea Banfi (University of Sussex)
- Bogdan Malaescu (Univ. P. et Marie Curie (Paris VI) (FR))
WG4: QCD and HFS: Hadron production
- There are no conveners in this block
WG4: QCD and HFS: Developments in Monte Carlo and resummations
- Claudia Glasman (Universidad Autonoma de Madrid)
- Andrea Banfi (University of Sussex)
- Bogdan Malaescu (Univ. P. et Marie Curie (Paris VI) (FR))
Dmitry Madigozhin
23/04/2013, 08:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
A sample of about 300 K+- --> pi+- gamma gamma rare decays with a background contamination below 10% has been collected by the NA48/2 and NA62 experiments at CERN during low intensity runs with minimum bias trigger configuration. The presented measurements of the decay spectrum and rate provide a crucial test of the Chiral Perturbation Theory (ChPT) describing weak low energy processes. Study...
David Muller
(SLAC)
23/04/2013, 08:50
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
The BABAR Collaboration has an intensive program of studying hadronic
cross sections at low-energy e+e- collisions, accessible at BaBar via
initial-state radiation. Our measurements allow significant
improvements in the precision of the predicted value of the muon
anomalous magnetic moment. These improvements are necessary for
shedding light on the current ~3.5 sigma difference between...
Khurelbaatar Begzsuren
23/04/2013, 09:10
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
The production of neutral strange hadrons is investigated using deep-inelastic scattering events measured with the H1 detector at HERA. The measurements are made in the phase space defined by the negative four-momentum transfer squared of the photon 7 < Q^2 < 100 GeV^2 and the inelasticity 0.1 < y < 0.6. The K_s and Lambda production cross sections and their ratios are determined. K_s...
2.
High precision measurement of the form factors of the semileptonic decays K+- -> pi0 l+- nu (Kl3)
Dmitry Madigozhin
23/04/2013, 09:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Alexander Bylinkin
23/04/2013, 09:50
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
Charged particle production in deep-inelastic $ep$ scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 < Q^2 < 100 GeV^2, and small values of Bjorken-x, 10^{-4} < x < 10^{-2}. The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity...
Dmytro Volyanskyy
23/04/2013, 11:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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 and energy flow in a kinematical range where QCD models have large uncertainties.
Measurements of charged & strange particle production and energy flow are performed in the approximate pseudorapidity range...
Orel Gueta
(Tel Aviv University (IL))
23/04/2013, 11:20
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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 -...
Frank Siegert
(Albert-Ludwigs-Universitaet Freiburg (DE))
23/04/2013, 11:40
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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....
David Wardrope
(University College London (UK))
23/04/2013, 12:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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 couplingโs strength at the highest energy scales. The results probe the consistency of the running of the coupling as predicted by QCD.
Juan Rojo Chacon
(CERN)
23/04/2013, 14:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
We study resonant pair production of heavy particles in fully hadronic
final states by means of jet substructure techniques.
We propose a new resonance tagging strategy that smoothly interpolates
between the highly boosted and fully unboosted regimes, leading to
approximately constant signal efficiencies and background rejection
factors for the whole allowed mass range.
As a case study,...
Javier Llorente Merino
(Universidad Autonoma de Madrid (ES))
23/04/2013, 14:20
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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 ->...
Geert Jan Besjes
(Radboud University Nijmegen (NL))
23/04/2013, 14:40
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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....
Deepak Kar
(University of Glasgow (GB))
23/04/2013, 15:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Dominik Duda
(Bergische Universitaet Wuppertal (DE))
23/04/2013, 15:20
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Piergiulio Lenzi
23/04/2013, 15:40
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
We present CMS results related to jet production cross sections, which pose a central test to perturbative QCD predictions and which place an important constraint on parton distribution functions and the strong coupling constant. Results include recent measurements performed with 2011 data taken at center-of-mass energy of 7 TeV and 2012 data taken at 8 TeV.
Konstantinos Vellidis
(Fermilab)
23/04/2013, 16:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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.
Andrii Iudin
23/04/2013, 16:50
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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,...
Michal Svatos
(Acad. of Sciences of the Czech Rep. (CZ))
23/04/2013, 17:10
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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,...
Ali Hanks
23/04/2013, 17:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
Direct photon tagged jets, in the form of photon-hadron correlations, are well
suited to provide unique insight into how jets interact with the quark
gluon plasma. Since high momentum photons are unmodified by the
strongly coupled medium produced at RHIC, the measured photon momentum
approximately balances that of the away-side parton. Therefore, the effective
modification to the...
Eric Jansen
(University College London (UK))
23/04/2013, 17:50
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Daniele Trocino
(Northeastern University (US))
23/04/2013, 18:10
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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.
Daniel Maitre
24/04/2013, 08:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
I will present the BlackHat one-loop library, which implements on-shell methods to compute one-loop amplitudes and show its use in conjuction with Sherpa to produce NLO accurate predictions for high multiplicity processes at the LHC and Tevatron. I will also discuss
the use of ROOT n-tuple files to store the information needed to compute different results and to transmit them to experimenters.
Francisco Campanario
(IFIC- University of Valencia)
24/04/2013, 08:50
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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.
Simon Plรคtzer
(DESY)
24/04/2013, 09:10
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
We discuss an extension of matrix element plus parton shower merging at leading and next-to-leading order. The algorithm does preserve inclusive cross sections at the respective input order. This constraint avoids potentially large logarithmic contributions, which would require approximate (N)NLO contributions to cancel against. We will report on the status of implementing the new procedure in...
Samantha Katherine Dooling
(Deutsches Elektronen-Synchrotron (DE))
24/04/2013, 09:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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 ย from hadronization, parton showering, multiple parton collisions. ย We examine current treatments of these
corrections and propose alternative methods to ย take into...
Hannes Jung
(DESY),
Hannes Jung
(Deutsches Elektronen-Synchrotron (DE))
24/04/2013, 09:50
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Daekyoung Kang
(MIT)
24/04/2013, 10:10
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
We predict cross sections in deep inelastic scattering (DIS) for the production of two jetsโone along the proton beam direction created by initial state radiation (ISR) and another created by final state radiation after the hard collision. Our results include fixed order corrections and a summation of large logarithms up to next-to-next-to-leading logarithmic (NNLL) accuracy in resummed...
Hamlet Zohrabyan
(DESY)
24/04/2013, 16:30
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
Measurements of very forward neutron and photon production as a function of Feynman-x in deep-inelastic ep scattering at HERA are presented. 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 analysis covers the range of negative four momentum transfer squared at the positron vertex 6<Q2<100 GeV^2, inelasticity...
Isabella Garzia
(University of Ferrara)
24/04/2013, 16:45
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
David Muller
(SLAC)
24/04/2013, 17:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
Low-energy e+e- annihilation processes are accessible at BaBar
via intiai state radiation. The e+e- -> p anti-p cross section
have been measured using a data set of about 500 fb-1, on a
wide energy range from the production threshold up to 4 GeV.
The proton magnetic form factor, and the ratio of the electric
over the magnetic form factors have been extracted from
the measured cross...
Daniel Santel
24/04/2013, 17:15
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
Quarkonium resonances and quarkonium-like states provide great information and insights on strong interactions of quarks and gluons. The Belle experiment has collected world's largest event sample of Y(1S), Y(2S), Y(4S) and Y(5S) decays using energy-asymmetric e+ e- collision at KEKB collider. In this talk we present recent results on b b-bar and c c-bar quarkonium spectroscopy and exotic...
Cyrille Marquet
25/04/2013, 11:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
I present a new QCD description of the ATLAS jet veto measurement, using the Banfi-Marchesini-Smye equation to constrain the inter-jet QCD radiation. This equation resums emissions of soft gluons at large angles, at leading-logarithmic accuracy, and accounts for both the so-called Sudakov and non-global logarithms. I show that this approach is able to reproduce the fraction of high-pT...
Yazid Delenda
(Universitรฉ Hadj Lakhdar - Batna)
25/04/2013, 11:20
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Mathias Ritzmann
(IPhT CEA/Saclay)
25/04/2013, 11:40
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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...
Malin Sjodahl
(Lund University)
25/04/2013, 12:00
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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....
Grigorios Chachamis
(IFIC (CSIC/UV) Valencia)
25/04/2013, 12:20
QCD and Hadronic Final States
Talk in Parallel Session at DIS2013
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.
