XX International Workshop on Deep-Inelastic Scattering and Related Subjects

Mar 26, 2012, 8:00 AM → Mar 30, 2012, 6:40 PM Europe/Berlin

Wolfgang Paul Lecture Hall (University of Bonn)

Ian Brock (Universitaet Bonn (DE))

Conference Logo (Banner) DIS_Logo_Final.jpg

Conference Logo (Square) DIS_Logo2_Final.jpg

Poster DIS_Poster_Final.pdf

Mon, March 26

9:00 AM → 10:30 AM Plenary

Convener: Ian Brock (Universitaet Bonn (DE))

9:00 AM Introduction

Speaker: Ian Brock (Universitaet Bonn (DE))

Slides brock_welcome.pdf

9:10 AM Introduction to deep inelastic scattering: past and present

Speaker: Joel Feltesse (DAPNIA)

Proceedings 6-feltesse_joel.pdf

Slides Feltesse_DIS_Intro.pdf

9:50 AM Precision measurements of the proton structure

Speaker: Iris Abt (Werner-Heisenberg-Institut)

Proceedings 7-abt_iris_2.pdf

Slides Abt_Iris_DIS.pdf

10:30 AM → 11:00 AM Coffee break

11:00 AM → 1:00 PM Plenary

Convener: Aharon Levy (Unknown)

11:00 AM alphas_s status

Speaker: Andre Hoang

Proceedings 19-hoang_andre.pdf

Slides Hoang_alphas_status.pdf Hoang_alphas_status.ppt

11:40 AM Status of polarised structure functions

Speaker: Claude Marchand (CEA - Centre d'Etudes de Saclay (FR))

Proceedings 20-marchand_claude.pdf

Slides Marchand-Plenary.pdf

12:20 PM Electroweak Precision Measurements and Direct Higgs Searches at the Tevatron

Speaker: David Waters (University College London)

Proceedings 21-waters_david.pdf

Slides Waters_EWK_Tevatron.pdf

1:00 PM → 2:30 PM Lunch break

2:30 PM → 4:35 PM Plenary

Convener: Sven-Olaf Moch (Unknown)

2:30 PM Welcome

Speaker: Ulf G. Meißner (University of Bonn)

2:35 PM QCD and the production of heavy bosons at the Tevatron

Speaker: Markus Wobisch (Louisiana Technical University (US))

Slides 120326-DIS2012.pdf 120326-DIS2012.ppt

3:15 PM Precise QCD measurements at HERA

Speaker: Karin Daum (University of Wuppertal/DESY)

Proceedings 23-daum_karin.pdf

Slides Daum_dis12v2.pdf

3:55 PM Theory developments in QCD

Speaker: Daniel De Florian (Laboratorio de Fisica Teorica Departamento de Fisica)

Slides deflorian-QCD.pdf

4:35 PM → 5:00 PM Coffee break

5:00 PM → 7:00 PM Plenary

Convener: Jochen Christian Dingfelder (Universitaet Bonn (DE))

5:00 PM Status of Higgs searches at ATLAS; jets+W/Z+top quark production at the LHC

Speaker: Oliver Kortner (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

Proceedings 25-kortner_oliver.pdf

Slides kortner.pdf

5:40 PM Quarks and gluons in heavy ion collisions

Speaker: Klaus Johannes Reygers (Ruprecht-Karls-Universitaet Heidelberg (DE))

Proceedings 26-reygers_klaus.pdf

Slides reygers_dis_2012_v4.pdf

6:20 PM Status of Higgs searches at CMS; new physics searches at the LHC

Speaker: Barbara Clerbaux (Universite Libre de Bruxelles (ULB)-Inter-University Institute f)

Proceedings 27-clerbaux_barbara.pdf

Slides DIS2012_Higgs_Searches_Clerbaux.pdf

7:00 PM → 10:00 PM Welcome reception

Tue, March 27

9:00 AM → 10:30 AM Diffraction and vector mesons

9:00 AM Combined inclusive diffractive cross sections measured with forward proton spectrometers at HERA

A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses diffractive deep inelastic scattering data measured by means of proton spectrometers. Correlations of systematic uncertainties are taken into account by the combination method,resulting in improved precision. The combined data cover the range 2.5 < Q2 < 200 GeV2 in photon virtualities, 0.00035 < xIP < 0.09 in fractional momentum losses, 0.09 < |t| < 0.55 GeV2 in four momentum transfer at the proton vertex and 0.0018 < beta < 0.56 in beta = x/xIP, where x is the Bjorken scaling variable.

Speaker: Valentina Sola (Universita e INFN (IT))

Proceedings 36-sola_valentina.pdf

Slides sola.pdf

9:20 AM Measurement of the Diffractive Longitudinal Structure Function F_L^D at HERA

First measurements are presented of the diffractive cross section $\sigma_{ep \rightarrow eXY}$ at centre-of-mass energies $\sqrt{s}$ of 225 and 252 GeV, together with a precise new measurement at $\sqrt{s}$ of 319 GeV, using data taken with the H1 detector in the years 2006 and 2007. Together with previous H1 data at $\sqrt{s}$ of 301 GeV, the measurements are used to extract the diffractive longitudinal structure function F_L^D in the range of photon virtualities 4.0 <= Q^2 <= 44.0 GeV^2 and fractional proton longitudinal momentum loss 5 10^{-4} <= x_{IP} <= 3 10^{-3}. The measured F_L^D is compared with leading twist predictions based on diffractive parton densities extracted in NLO QCD fits to previous measurements of diffractive Deep-Inelastic Scattering and with a model which additionally includes a higher twist contribution derived from a colour dipole approach. The ratio of the diffractive cross section induced by longitudinally polarised photons to that for transversely polarised photons is extracted and compared with the analogous quantity for inclusive Deep-Inelastic Scattering.

Speaker: David Salek (CERN)

Slides FLDDIS2012.pdf

9:40 AM Inclusive Measurement of Diffractive Deep Inelastic Scattering at HERA

Measurements of the cross section for the diffractive process ep -> eXY are presented, where Y is a proton or a low mass proton excitation carrying a fraction 1 − xIP > 0.95 of the incident proton longitudinal momentum and the squared four-momentum transfer at the proton vertex satisfying MY < 1.6 GeV and |t| < 1.0 GeV^2. Using data taken by the H1 experiment, the cross section is measured for photon virtualities in the range 3 <= Q2 < =1600 GeV^2, triple differentially in xIP , Q^2 and beta = x/xIP , where x is the Bjorken scaling variable. Thesemeasurements are made after selecting diffractive events by demanding that a large rapidity interval separates the final state hadronic systems X and Y . New measurements covering data taking periods 1999-2000 and 2004-2007 are combined with previously published results in order to provide a single set of diffractive cross sections using the large rapidity gap selection method from the H1 experiment. Comparisons of measurements with predictions from the diffractive parton density and dipole models are shown. Finally, the proton vertex factorisation hypothesis, which is an important aspect in the modelling of diffractive structure, is discussed.

Speaker: Emmanuel Sauvan (LAPP (IN2P3/CNRS))

Proceedings 209-sauvan_emmanuel.pdf

Slides esauvan_f2d_dis2012.pdf

10:00 AM Measurement of Dijet Production in Diffractive Deep-Inelastic Scattering with a Leading Proton at HERA

The cross section of diffractive deep-inelastic scattering ep \rightarrow eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement is performed for fractional proton longitudinal momentum loss xIP < 0.1 and covers the range 0.1 < |t| < 0.7 GeV2 in squared four-momentum transfer at the proton vertex and 4 < Q2 < 110 GeV2 in photon virtuality. The differential cross sections extrapolated to |t| < 1 GeV2 are in agreement with next-toleading order QCD predictions based on diffractive parton distribution functions extracted from measurements of inclusive and dijet cross sections in diffractive deep-inelastic scattering. The data are also compared with leading order Monte Carlo models.

Speaker: Richard Polifka (University of Toronto (CA))

Proceedings 211-polifka_richard_1.pdf

Slides Polifka.pdf Polifka_PrintVersion.pdf

9:00 AM → 10:30 AM Electroweak and searches

9:00 AM SM Higgs production in theory

I will briefly review Standard Model Higgs production and decay mechanisms and report on the status of the art of existing predictions, with major focus on the single Higgs production cross-section.

Speaker: Franz Herzog (ETH Zurich)

Slides Herzog.pdf

9:18 AM Search for the Standard Model Higgs boson at ATLAS

The experimental results of the search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV are reported, based on a total integrated luminosity of up to 4.9 fb-1 collected by the ATLAS detector in 2011. The search combines several Higgs boson decay channels in the mass range from 110 GeV to 600 GeV and derives upper limits on the production cross section as a function of the Higgs boson mass. A wide range of Higgs boson mass hypotheses is excluded at a 95% confidence level. Some excess of events is also reported.

Speaker: Dr Prolay Kumar Mal (CEA - Centre d'Etudes de Saclay (FR))

Proceedings 75-mal_prolay.pdf

Slides SMHiggsSearchesATLAS_ProlayMal.pdf

9:42 AM Searches for SM Higgs at CMS

We present results of the search for the standard model Higgs boson at CMS.

Speaker: Pietro Govoni (CERN)

Proceedings 219-govoni_pietro.pdf

Slides 2012-03-27-govoni-DIS12.pdf

10:06 AM Status of SM Higgs searches at the Tevatron

We present results from the search for a standard model Higgs boson using up to 10/fb of proton-antiproton collision data produced by the Fermilab Tevatron at a center-of-mass energy of 1.96 TeV. The data were recorded by the CDF and D0 Detectors between March 2001 and September of 2011. Updated results from many exclusive channels as well as the combined Tevatron search are presented.

Speaker: Kyle Knoepfel (F)

Proceedings 278-knoepfel_kyle.pdf

Slides Knoepfel.pdf

9:00 AM → 10:40 AM Future of DIS

9:00 AM The ATLAS Upgrade Programme

Speaker: Claudia Gemme (Universita e INFN (IT))

Proceedings 346-gemme_claudia.pdf

Slides DIS12_Gemme_V3_Extras.pdf

9:25 AM The ALICE Upgrade Programme

Speaker: Thomas Peitzmann (University of Utrecht (NL))

Proceedings 345-peitzmann_thomas.pdf

Slides alice-upgrade-dis2012.pdf

9:50 AM The LHCb upgrade

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 overcome without improving the detector. We therefore plan for an upgraded spectrometer by 2018 with a 40 MHz readout and a much more flexible software-based triggering system that will increase the data rate as well as the efficiency specially in the hadronic channels. Here we present the LHCb detector upgrade plans, based on the recently submitted Letter of Intent, with a particular focus on prospects for QCD-related physics analyses.

Speaker: Renaud Le Gac (Universite d'Aix - Marseille II (FR))

Proceedings 150-legac_renaud.pdf

Slides DIS12_LHCbUpgrade_RLG.pdf

9:00 AM → 10:30 AM Hadronic final states

9:00 AM Isolated photons+jet in DIS

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 gamma+jet cross sections are presented as functions of the jet transverse energy and pseudorapidity. Leading-logarithm parton-shower Monte Carlo predictions and perturbative QCD calculations were compared to the data.

Speaker: Oleg Kuprash (DESY)

Proceedings 44-kuprash_oleg.pdf

Slides kuprash_isolated_photons_v3.pdf

9:20 AM Photon Results from CDF

Prompt isolated photon pairs production cross sections, as well as direct photon production in association with a heavy (b or c) quark jets are presented. Differential cross sections are presented as a function of several variables. The results are compared with a next-to-leading order perturbative QCD calculations.

Proceedings 167-vellidis_konstantinos_1.pdf

Slides cdf_photons_dis2012.pdf

9:40 AM Photon+jets measurements in ppbar Collisions at D0

Photon+jets measurements in ppbar Collisions at D0

Speaker: Nikolai Skachkov (Joint Inst. for Nuclear Research (RU))

Slides Skachkov-DIS-Bonn-2012.pdf Skachkov-DIS-Bonn-2012.ppt

10:00 AM Photon and photon+jet production measured with the ATLAS detector

Isolated prompt photons provide a direct probe of short-distance physics, complementary to that provided by measurements of jets or vector-bosons. The inclusive prompt photon cross section has been measured over a wide range of transverse momenta; the diphoton cross section has also been measured as a function of diphoton mass, total transverse momentum and azimuthal separation; the cross section for photons produced in association with jets is also measured. The results use data to suppress backgrounds, and also to remove the effects of underlying event and multiple proton-proton interactions in a theoretically well-controlled manner. The results are compared to the predictions of next-to-leading-order QCD.

Speaker: Leonardo Carminati (Università degli Studi e INFN Milano (IT))

Proceedings 81-carminati_leonardo.pdf

Slides PhotonATLASCarminatiDIS2012.pdf

9:00 AM → 10:30 AM Heavy flavours

9:00 AM Inclusive D- and B-Meson Production at the LHC

I present predictions for the inclusive production of D- and B-mesons at the CERN LHC in the general-mass variable-flavor-number scheme at next-to-leading order, an approach which takes into account the finite mass of the heavy quarks. Numerical results are compared to data where available. Measurements at large rapidities have the potential to pin down models of intrinsic charm.

Speaker: Hubert Spiesberger (Univ. Mainz)

Proceedings 249-spiesberger_hubert.pdf

Slides spiesberger.pdf

9:18 AM Heavy Flavour Production in ATLAS

ATLAS has studied heavy flavour production in a variety of decay channels and inclusive signatures including charmed mesons, jets originating from b-quarks and inclusive muons and electrons. Differential production cross sections for beauty and charm are extracted from these signatures and compared with a variety of theoretical predictions.

Speaker: Adam Edward Barton (Lancaster University (GB))

Proceedings 86-barton_adam.pdf

Slides MyHeavy_Flavour_Production_from_ATLAS.pdf

9:36 AM Measurements of beauty quark production at CMS

Abstract missing

Speaker: Wolfram Erdmann (Paul Scherrer Institut (CH))

Proceedings 237-erdmann_wolfram.pdf

Slides CMS-b-production-dis2012.pdf

9:54 AM Open heavy flavor production in pp collisions with ALICE at LHC

ALICE is the LHC experiment dedicated to the study of the Quark Gluon Plasma (QGP) in Pb-Pb collisions. Heavy quarks are ideal probes to explore the QGP formation and properties, since they experience the full collision history and are expected to be abundantly produced at the LHC. It is of great importance to measure the heavy flavor cross section not only in Pb-Pb collisions, but also in pp collisions. In fact, the measurement in the latter is used both as a reference for the Pb-Pb results and as test of the pQCD predictions in a new energy domain. ALICE measures heavy quark production both at central and forward rapidity, reconstructing heavy flavour particles, both exclusively, using a selection of hadronic decay channels, and inclusively, using single leptons. Since the start up of the LHC, ALICE has been collecting Pb-Pb data at √sNN = 2.76 TeV and pp data at √s = 2.76 and 7 TeV. We present results on the measurement of heavy quark production through the hadronic decay channels of D mesons and via single leptons, with emphasis on the results obtained with pp data.

Speaker: Rosa Romita (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

Proceedings 130-romita_rosa.pdf

Slides rromita_DIS.pdf rromita_DIS.ppt

10:12 AM Production of c-cbar pairs at LHC: k_t-factorization and double-parton scattering

We discuss charm production at LHC. The production of single $c \bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. Some of them include effect of small-$x$ saturation and fulfill Balitsky-Kovchegov evolution equation. The hadronization is included with the help of fragmentation functions found for the production of $c$ ($\bar c$) in $e^+ e^-$ collisions. Differential distributions for several charmed mesons will be presented and compared to recent results of the ALICE and LHCb collaborations. Some missing strength is identified. Different schemes of fragmentation are discussed. Furthermore we discuss production of two pairs of $c \bar c$ within a simple formalism of double-parton scattering (DPS). Surprisingly large cross sections, comparable to single-parton scattering (SPS) contribution, are predicted for LHC energies. Both total inclusive cross section as a function of energy and differential distributions are shown. We include recently discussed evolution of double partons in the case of two scales. We discuss perspectives how to identify the double scattering contribution. We find much larger cross section for large rapidity distance between charm quarks from different hard parton scatterings compared to single scattering. First predictions for two $c \bar c$ pair production in single-parton scattering will be presented. Predictions for the production of different pairs of charm mesons ($D0 $D0$, D0 {\bar D}0$, etc.) are presented for the kinematics of LHCb experiment. I will show also predictions for so-called nonphotonic electrons and muons coming from the semileptonic decays of charmed mesons. The double-parton scattering gives large contribution with large (pseudo)rapidity gap between electrons ($e^+ e^+, $e^- e^-, $e^+ e^-$) or muons. This can be measured experimentally.

Speaker: Prof. Antoni Szczurek (Cracow, INP & Rzeszow Univ.)

Proceedings 213-szczurek_antoni_1.pdf

Slides szczurek_dis2012_4c.pdf

9:00 AM → 10:30 AM Spin physics

9:00 AM Helicity Structure of the Nucleon: Recent Results

We give an overview of the recent developments on longitudinal spin physics and the nucleon's helicity structure. We highlight the status of theoretical calculations and the impact of recent data.

Speaker: Werner Vogelsang

Slides DIS12.pdf

9:35 AM Recent Results of Double Helicity Asymmetries at PHENIX

The determination of the gluon polarization within the proton, $\Delta G$, is one of the critical pieces to understanding the proton spin puzzle. Using collisions of polarized protons with $\sqrt{s}=200 \:GeV$ and $\sqrt{s}=500 \:GeV$ at the Relativistic Heavy Ion Collider (RHIC), PHENIX can access gluons and $\Delta G$ at leading order. Constraints on $\Delta G$ come from measurements of double longitudinal asymmetries, $A_{LL}$, of various particle production cross sections. We will present the recent $A_{LL}$ results at central $(|{\eta}|<0.35)$ and forward $(3.1 < |{\eta}| < 3.9)$ rapidities along with comparisons to various models of the gluon polarization. A summary of the current issues limiting the precision of these measurements will follow. Finally, we will discuss the possibilities in the near to mid-term future of the PHENIX $\Delta G$ program, specifically, constraining $\Delta G$ at low-x.

Speaker: Mr Scott Wolin (University of Illinois at Urbana-Champaign)

Proceedings 108-wolin_scott.pdf

Slides 12_03_20_DIS.ppt

10:00 AM New COMPASS Results on Polarized Parton Distributions Inside the Nucleon

A short review of the COMPASS results concerning gluon polarization inside the nucleon, DG/G, is given including two new measurements: Firstly, a DG/G determination in leading order and in three bin of the gluon momentum fraction x_g from asymmetries in high-p$_T$ hadron pair production for Q$^2>$1 (GeV/c)$^2$; secondly, a preliminary next-to-leading order analysis based on open charm production, i.e. D mesons decaying via various channels. The latter result is obtained from our combined proton and deuteron data. In addition the cross-section for the $D^*$ production is given and kinematic distribution of the $D^*$ are compared with the AROMA generator. Finally results for the LO flavor separation of the three lightest quark polarized parton distributions.

Speaker: Marcin Stolarski (LIP Laboratorio de Instrumentacao e Fisica Experimental de Part)

Proceedings 307-stolarski_marcin.pdf

Slides stolarski.pdf

9:00 AM → 10:35 AM Structure functions

9:00 AM Measurement of high-Q2 e+p neutral current cross sections at HERA and determination of the structure function xF3

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 negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 136 pb-1 taken in 2006 and 2007 at a centre-of-mass energy of 318 GeV. The structure functions xF_3 and xF_3^{\gammaZ} are determined by combining the e+p results presented in this analysis with previously measured e-p neutral current data. The measured cross sections are compared to the predictions.

Speaker: Friederike Januschek (DESY)

Proceedings 34-januschek_friederike.pdf

Slides Januschek_DIS2012.pdf

9:20 AM Luminosity Measurement at HERA with Elastic QED Compton Events

At HERA, deep inelastic scattering progresses have been studied in order to probe the fundamental forces predicted by the standard model and the structure of the proton. One of the most fundamental processes is the elastic production of photons, e p -> e p gamma. For the case where the momentum transfer at the proton vertex is small, but both the electron and the photon have significant transverse momentum, the process is referenced as elastic QED Compton scattering. This process has the feature that it may be calculated at high precision in the framework of perturbative QED, and experimental background from other processes, like deeply-virtual Compton scattering, is small. In this analysis, the rate of elastic QED Compton events together with the cross section predicted from QED in used to measure the integrated luminosity of H1 datasets. The results are compared to default measurements of the integrated luminosity using Bethe-Heitler events.

Speaker: Stefan Schmitt (Ruprecht-Karls-Universitaet Heidelberg (DE))

Proceedings 109-schmitt_stefan.pdf

Slides qedc32_dis.pdf

9:40 AM W,Z production at ATLAS, constraints on parton density functions and determination of the strange sea density

Merged abstract: "W/Z production at ATLAS, and constraints on parton density functions" "QCD analysis of the ATLAS W-> lnu and Z ->ll cross-sections measurements and determination of the strange sea density"

Speaker: Uta Klein (University of Liverpool (GB))

Slides Talk_UK_27.03.2012.pdf

10:10 AM QCD NLO analysis of inclusive, charm and jet data (HERAPDF 1.7)

A preliminary global NLO QCD analysis of the HERA data is presented. The following data sets are used in this analysis: the NC and CC inclusive DIS cross sections obtained from the combination of the measurements from H1 and ZEUS based on HERA I and HERA II data at the nominal proton beam energy, the preliminary combined inclusive NC DIS cross sections at reduced proton beam energies,the inclusive jet cross sections from H1 and ZEUS and the preliminary combined HERA results on the structure function F2(charm).

Speaker: Krzysztof Nowak (Deutsches Elektronen-Synchrotron (DE))

Proceedings 35-nowak_krzysztof_1.pdf

Slides 12.03.27-DIS12.pdf

10:40 AM → 11:00 AM Coffee break

11:00 AM → 12:30 PM Diffraction and vector mesons

11:00 AM QCD fits in diffractive DIS revisited

A new method for the extraction of diffractive parton distributions is presented which avoids the use of Regge theory ansatz and is in much closer relation with the factorization theorem for diffractive hard processes.

Speaker: Federico Alberto Ceccopieri (Fondazione Angelo Della Riccia Ente Morale)

Proceedings 282-ceccopieri_federico.pdf

Slides 1._ceccopieri_DIS12.pdf

11:20 AM A global analysis of diffractive events at HERA

We extract diffractive parton distribution functions (DPDFs) and diffractive structure functions from the most recent H1 and ZEUS diffractive DIS data obtained by various methods. We consider Pomeron as an object with parton distribution function, evolving according to the next-to-leading order (NLO) DGLAP equations within the framework of the ‘Fixed Flavour Number Scheme’ (FFNS). Having performed a global fit analysis, we achieve a very good description of all available measurements by introducing a new set of quark distribution form for the Pomeron. We predict longitudinal and charm proton diffractive structure function as well. Our results are compared with other analysis from the literature.

Speaker: Mrs Sara Taheri Monfared (Semnan university and IPM)

Proceedings 52-taheri_sara.pdf

Slides S._Taheri-DIS2012.pdf

11:40 AM Evidence for breakdown of the DGLAP description in diffractive DIS at HERA

HERA data on diffractive DIS show deviations from twist 2 DGLAP predictions below Q^2 5 GeV^2 at low x_P, which may reach up to 100%. These deviations are consistent with higher twists effects extracted from the saturation model. It is a first direct evidence for the higher twists in DIS. This finding affects determination of the diffractive parton densities that are used for the predictions at the LHC.

Speaker: Mariusz Sadzikowski (Jagiellonian University)

Proceedings 134-sadzikowski_mariusz.pdf

Slides evidence_for_breakdown_of_the_DGLAP.pdf

12:00 PM Analysis of higher twists in DIS and diffractive DIS at HERA and its implications for the saturation model

We present new results on determination of higher twist contributions in diffractive DIS and compare them to the inclusive DIS case. In both cases the framework for the estimates is provided by the saturation model. We discuss the methods of higher twist extraction from the saturation model and compare the results for DIS and DDIS. We point out a striking difference in higher twist importance between DIS and DDIS: at low Q2 the effects are minor in DIS and they are large in DDIS. Moreover a comparison to HERA data hints on a necessary improvement of higher twist treatment in the saturation model. We present a possible QCD explanation of both findings.

Speaker: Leszek Motyka (Jagellonian Univerisity)

Slides distwist.pdf

11:00 AM → 12:30 PM Electroweak and searches

11:00 AM A theoretical review of the BSM Higgs

A review the status of the BSM Higgs (excluding supersymmetry) with particular emphasis on the composite Higgs, the connection to light custodians.

Speaker: Aleksandr Azatov

Proceedings 176-aleksandr_azatov.pdf

Slides azatov.pdf

11:18 AM Searches for BSM Higgs at CMS

We present results of searches for the non-standard-model Higgs bosons at CMS.

Speaker: Javier Fernandez Menendez (Universidad de Oviedo (ES))

Proceedings 220-fernandez_javier.pdf

Slides fernandez.pdf

11:36 AM Searches for Beyond-Standard Model Higgs boson at ATLAS

The discovery of a neutral Higgs boson with large decay branching fraction to tau and muon pairs, as well as the discovery of a charged Higgs boson would represent a strong evidence of new physics beyond the Standard Model. The experimental results of the searches for the Higgs bosons beyond the Standard Model with the ATLAS detector are reported. The searches are based on an integrated luminosity of up to 4.9 fb-1 of proton-proton collision data recorded at the Large Hadron Collider (LHC) at a centre-of-mass energy of 7 TeV. Exclusion limits on production cross-sections are given as function of the Higgs boson mass and are analyzed in the framework of the minimal supersymmetric model.

Speaker: Bruno Lenzi (CERN)

Proceedings 74-lenzi_bruno.pdf

Slides BL_BSM_Higgs_ATLAS.pdf

11:54 AM Searches for low-mass Higgs states at BABAR

Several types of new-physics models predict the existence of low-mass Higgs states. Previous BABAR searches for leptonic and invisible light-Higgs decays have excluded large regions of model parameter space. We present new searches for hadronic Higgs decays and for a dark-sector Higgs produced in association with a dark gauge boson.

Speaker: Valentina Santoro (University of Ferrara)

Proceedings 187-santoro_valentina.pdf

Slides DIS2012v3.pdf

12:12 PM BSM Higgs and other bump searches at the Tevatron

In Beyond Standard Model (BSM) theories such as supersymmetry, the electroweak symmetry breaking mechanism predicts one or several Higgs bosons with different couplings and masses compared to the Standard Model one. We will present the constraints on BSM theories coming from searches for exotic Higgs bosons from the CDF and D0 collaborations at the Tevatron. In addition, other bump searches will also be presented, such as in the dijet mass spectrum in W+2jets events.

Speaker: Emilien Chapon (Centre d'Etudes de Saclay (CEN Saclay)-Unknown-Unknown)

Proceedings 279-chapon_emilien_2.pdf

Slides chapon.pdf

11:00 AM → 12:40 PM Future of DIS

11:00 AM DIS at MINERvA

Speaker: Joel Mousseau

Proceedings 348-mousseau_joel.pdf

Slides Mousseau.odp Mousseau.pdf

11:25 AM Impact of future neutrino experiments to DIS

none

Speaker: Jorge G. Morfin (Fermilab)

Proceedings 321-morfin_jorge.pdf

Slides DIS12-Morfin.pdf

11:50 AM The E-906/SeaQuest experiment at Fermilab

The E-906/SeaQuest experiment at Fermilab will continue a series of Drell-Yan measurements to explore the antiquark structure of the nucleon and nuclei. To extend existing measurements to larger values of Bjorken-x, a 120 GeV proton beam extracted from Fermilab's main injector is used, resulting in a factor of 50 more luminosity than previous experiments and enabling access to values of x up to 0.9. An overview will be presented of the key physics goals of the E-906/SeaQuest collaboration. These include investigation of the dramatic dbar/ubar flavor asymmetry in the nucleon sea and its behavior at high x; study of the EMC effect in Drell-Yan scattering and the unexpected absence of any antiquark excess in existing data; and measurements of the angular dependence of the Drell-Yan process, sensitive to spin-orbit correlations within the nucleon. The talk will conclude with a status report on the ongoing commissioning of this new experiment.

Speaker: Dr Markus Diefenthaler (University of Illinois at Urbana-Champaign)

Slides Diefenthaler-SeaQuest.pdf

12:15 PM Future Programme of COMPASS at CERN

COMPASS at CERN is preparing for a new series of measurements on the nucleon structure comprising deep virtual Compton scattering and hard exclusive meson production using muon beams, as well as Drell-Yan reactions using a polarised proton target and a negative pion beam. The former will mainly constrain the generalized parton distribution H and determine the transverse size of the nucleon, while the later measurements will provide information on transverse-momentum dependent (TMD) PDFs. Of particular interest is to verify the predicted change of sign of T-odd TMD PDFs going from DIS to Drell-Yan reactions. The necessary hardware upgrades and the projected results of the programme will be discussed.

Speaker: Dr Gerhard Mallot (CERN)

Proceedings 141-mallot_gerhard.pdf

Slides 2012_mallot_dis.pdf

11:00 AM → 12:40 PM Hadronic final states

11:00 AM Jet-veto efficiencies at all orders in QCD

We present accurate (NLL+NNLO) predictions for jet-veto efficiencies for Higgs and Z production at the LHC, obtained with the automated resummation program CAESAR. We discuss all sources of theoretical uncertainties associated to the presented results, highlighting which further calculations would be needed in order to reduce them.

Speaker: Andrea Banfi (Freiburg U)

Proceedings 269-banfi_andrea.pdf

Slides ABanfi_dis2012.pdf

11:20 AM From Jet Counting to Jet Vetoes

The properties of jets are used in many LHC physics searches. Higgs searches use jet vetoes and fixed recoil jet multiplicities. Searches for new physics particles require a careful distinction of decay jets from QCD jet radiation. We show that the exclusive number of jets at hadron colliders can be described with two simple patterns: staircase scaling and Poisson scaling. In photon plus jets production we can interpolate between the two patterns using simple kinematic cuts. The associated theoretical errors are well under control. We show how understanding the exclusive jet multiplicities significantly impacts Higgs searches and searches for supersymmetry at the LHC.

Speaker: Peter Schichtel (ITP)

Proceedings 230-schichtel_peter.pdf

Slides talk.pdf

11:40 AM Measurements of jet production in pp collisions with the ATLAS detector

Differential jet cross sections and distributions have been measure inclusively, in dijet events and in multijet events, using information from the ATLAS calorimeters and tracking detectors. The inclusive jet measurements extend from 20 GeV to 1.5 TeV, and the dijet measurements cover a very wide mass range. Measurements based on tracking alone are sensitive only to the charged-particle content of the jet, but all accurate measurements down to low transverse momentum, where the onset of hard scattering can be studied as jets emerge from some scattering events. A wide range of QCD-based calculations is confronted with the data, ranging from soft physics models the high multiplicity partonic matrix elements and NLO QCD calculations matched to parton shower simulations, testing the understand of QCD in a new kinematic range.

Speaker: Adam Yurkewicz (Northern Illinois University (US))

Proceedings 79-yurkewicz_adam.pdf

Slides DIS_yurkewicz.pdf

12:00 PM Jets and multi-jets at large rapidities in p-p collisions at the LHC [CMS]

Jets and multi-jets at large rapidities in p-p collisions at the LHC

Speaker: Thomas Schoerner-Sadenius (Deutsches Elektronen-Synchrotron (DE))

Proceedings 184-schoernersadenius_thomas.pdf

Slides CMS.FwdJets.DIS2012.pdf

12:20 PM The High-Energy-Jets framework applied to multi-jet production

The theoretical description of multi-jet final states is an issue of great importance at the LHC. The High Energy Jets (HEJ) framework offers a new approach to this and provides an all-order resummation of the dominant contributions from wide-angle QCD radiation. I will give a brief introduction to the framework and then show comparisons to early data from ATLAS and CMS analyses and discuss comparisons with other theoretical frameworks. I will end by discussing current ongoing developments.

Speaker: Jennifer Smillie

Proceedings 233-smillie_jennifer.pdf

Slides SmillieDIS.pdf

11:00 AM → 12:30 PM Heavy flavours

11:00 AM Constraining the intrinsic charm/bottom content of the nucleon via photon + heavy quark production

The production of a prompt photon in association with a heavy-quark (charm or bottom) jet is a versatile process that can be used to study the structure of the proton and the nucleus. This process is extremely sensitive to the heavy quark PDFs, and can thus directly probe for intrinsic charm or bottom contributions. We present various predictions of this process at different colliders and detectors (D0,CDF, RHIC, ATLAS, CMS and LHCb) portraying how the different kinematic ranges affect the constraint of IC/IB.

Speaker: Karol Kovarik (KIT)

Proceedings 250-kovarik_karol_1.pdf

Slides DISphoton-kovarik.pdf

11:18 AM Fully massive scheme for jet production in DIS

We present the consistent treatment of heavy quarks in jet production processes in DIS at NLO accuracy. The method is based on the ACOT massive factorization scheme (Aivazis-Collins-Olness-Tung) which is already in use in global fits for PDFs. Extension of this method to jets faces the problem of infra-red singularities, which have to cancel between real and virtual corrections. Moreover, potential mass singularities have to be controlled in both contributions. To this end, we extended the dipole subtraction method (S. Catani, S. Dittmaier, M. H. Seymour, Z. Trocsanyi), which in its original form did not take into account QCD massive splittings in the initial state. We constructed relevant kinematics and dipole splitting functions together with their integrals. We partially adapted the method in MC program and checked against the known massive inclusive NLO results.

Speaker: Piotr Kotko

Proceedings 116-kotko_piotr.pdf

Slides Piotr_Kotko_DIS2012.pdf

11:36 AM Measurements with ATLAS detector of jets containing charm and bottom quarks

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass, the azimuthal angle difference between the two jets, and the angular variable chi in two dijet mass regions. The results are compared to next-to-leading-order QCD predictions. D*+/- meson production in jets is also measured. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate.

Speaker: David Calvet (Univ. Blaise Pascal Clermont-Fe. II (FR))

Proceedings 88-calvet_david.pdf

Slides DIS2012-88.pdf

11:54 AM Measurement of Inclusive D* Meson and D* Meson Dijet Cross Sections in Photoproduction at HERA

The inclusive photoproduction of D* mesons and of D*-tagged dijets is investigated with the H1 detector at the $ep$ collider HERA. The kinematic region covers small photon virtualities $Q^{2} < 2\ {\rm GeV}^2$ and photon-proton centre-of-mass energies of $100 < W_{\gamma p} < 285\ {\rm GeV}$. Inclusive \dstar\ meson differential cross sections are measured for central rapidities $|\eta(D*)| < 1.5$ and transverse momenta $p_{T}(D*) >1.8\ {\rm GeV}$. The heavy quark production process is further investigated in events with at least two jets with transverse momentum $\ptj > 3.5\ {\rm GeV}$ each, one containing the \dstar\ meson. Differential cross sections for D*-tagged dijet production and for correlations between the jets are measured in the range $|\eta(D*)| < 1.5$ and $p_{T}(D*) >2.1\ {\rm GeV}$. The results are compared with predictions from Monte Carlo simulations and next-to-leading order perturbative QCD calculations.

Speaker: Zlatka Georgieva Staykova (University of Antwerp (BE))

Slides dis2012.pdf

12:12 PM Measurements of open heavy flavor production by PHENIX at RHIC

Heavy flavor quarks are produced in the early stages of heavy ion collisions and serve as an important probe of the strongly interacting deconfined medium believed to be produced in these collisions at RHIC. Measuring observables such as Nuclear Modification Factor and Elliptic Flow for open heavy flavor production can help in quantifying medium effects. Measurement of heavy flavor production in p+p collision is an absolutely necessary baseline measurement for nuclear modification factor. On the other hand, measurements of heavy quark production in p+p collisions provides an important cross-check of pQCD calculations. PHENIX has a unique ability to measure single lepton spectra both at |eta|< 0.35 and at 1.4<|eta|<1.9 rapidity ranges, with its Central and Muon arms, respectively. Single leptons are used to tag the production of heavy flavor quarks via semileptonic decay of heavy flavor mesons (D,B). The most recent PHENIX single lepton measurements for different colliding ion systems will be presented and compared to the most recent available theoretical model predictions.

Speaker: Irakli Garishvili (Lawrence Livermore Nat. Laboratory (US))

Slides DIS2012_garishvili.pdf DIS2012_garishvili.pptx

11:00 AM → 12:30 PM Spin physics

11:00 AM TMD Theory Overview

Transverse momentum dependent (TMD) distribution and fragmentation functions are described as Fourier transforms of matrix elements containing non-local combinations of quark and gluon fields. While the collinear functions are light-cone correlators in which the non-locality is restricted along the light-cone, the transverse momentum dependent functions are light-front correlators including a transverse (space-like) separation away from the light-cone. In the matrix elements the time-ordering is superfluous and they are parts of the full (squared) amplitudes that account for the connections to the hadrons (soft parts). The collinear (x-dependent) parton (quark or gluon) distribution functions (PDF’s) that appear in the parameterization of collinear leading-twist correlators are interpreted as momentum densities including polarized parton densities in polarized hadrons. They involve only spin-spin densities and they do not allow for a description of single-spin asymmetries in high-energy scattering processes at leading 1/Q order in the hard scale Q. TMD (x and pT-dependent) PDF’s that appear in the parameterization of TMD correlators include spin-spin as well as momentum-spin correlations and they are able to describe single-spin and azimuthal asymmetries, such as Sivers and Collins effects in semi-inclusive deep inelastic scattering (SIDIS), but there are many open issues on pT-factorization. Upon taking moments in pT (or taking Bessel weights) the correlators involve higher-twist operators, but evaluated at zero-momentum (gluonic pole matrix elements). They can be incorporated in a ‘generalized’ factorization scheme with specific gluonic pole factors such as the sign in SIDIS versus Drell-Yan, which can be traced back to having TMD’s with non-trivial process-dependent past- or future-pointing gauge links appearing in the light-front separated, non-local operator combinations.

Speaker: Piet J Mulders (VU University)

Proceedings 107-mulders_piet.pdf

Slides Mulders_Piet_107.pdf Mulders_Piet_107.ppt

11:35 AM One-Hadron transverse spin asymmetries at COMPASS

The quark content of the nucleon at twist-two level in the collinear case can be fully characterized by three independent distribution functions for each quark flavour: the unpolarized distribution function f1(x), the helicity distribution function g1(x) and the transverse spin distribution function h1(x), also called transversity. The measurements of single spin asymmetries in semi-inclusive deep inelastic scattering (SIDIS) on a transversely polarized target are an important part of the COMPASS physics program. By measuring azimuthal asymmetries in hadron production one can access both transversity - using the Collins fragmentation function - and the Sivers distribution function. The COMPASS collaboration has measured these asymmetries in the scattering of a 160 GeV/c polarized mu+ beam off a transversely polarized 6LiD (deuteron) target in the years 2002-2004 and off a transversely polarized NH3 (proton) target in 2007 and 2010. In this contribution we present the results from the 2010 data for the Collins and Sivers asymmetries.

Speaker: Christoph Adolph (Friedrich-Alexander-Univ. Erlangen (DE))

Proceedings 174-adolph_christoph.pdf

Slides dis2012_adolph.pdf

12:00 PM Azimuthal distributions of charged hadrons, pions, and kaons produced in deep-inelastic scattering off unpolarized protons and deuterons

The azimuthal $\cos\phi$ and $\cos2\phi$ modulations of the distribution of hadrons produced in unpolarized semi-inclusive deep-inelastic scattering of electrons and positrons off hydrogen and deuterium targets have been measuread at the HERMES experiment. For the first time these modulations were determined in a four-dimensional kinematic space for positively and negatively charged pions and kaons separately, as well as for unidentified hadrons. These azimuthal dependences are sensitive to the transverse motion and polarization of the quarks within the nucleon via, e.g., the Cahn, Boer-Mulders and Collins effects.

Speaker: Francesca Giordano (U)

Proceedings 137-giordano_francesca.pdf

Slides Giordano_dis12.pdf

11:00 AM → 12:55 PM Structure functions

11:00 AM Impact of LHC data on (NN)PDFs

A determination of parton distribution functions with reliable estimation of associated uncertainties is a key ingredient for exploiting the full physics potential of the experiments at the LHC collider. On the other hand, measurements from the LHC will provide important constraints on PDFs in kinematic regions which are so far not covered by data included in global analyses. In this talk I will discuss the effect of including recent LHC vector boson and inclusive jet production measurements into the NNPDF global parton fit. I will also show how the impact of including new data in a global fit can be rapidly assessed using a method based on Bayesian reweighting.

Speaker: Dr Maria Ubiali (RWTH Aachen University)

Slides ubiali-dis2012.pdf

11:25 AM ABM11 PDFs and benchmarks at NNLO

We present a determination of the nucleon parton distribution functions (ABM11) and the strong coupling constant $\alpha_s$ at next-to-next-to-leading order (NNLO) in QCD based on world data for deep-inelastic scattering and fixed-target data for Drell-Yan process. The analysis is performed in the fixed-flavor number scheme for $n_f=3,4,5$ and uses the \MSbar scheme for $\alpha_s$ and the heavy quark masses. The fit results are compared with other NNLO PDFs and used to compute the benchmark cross sections at hadron colliders to NNLO accuracy.

Speaker: Sergey Alekhin

Proceedings 302-alekhin_sergey.pdf

Slides 2.)ABM11_PDFs_and_benchmarks_at_NNLO.pdf

11:50 AM Progress in the dynamical parton distributions

Different theoretical improvements and the inclusion of alternative data sets in the determination of dynamical parton distribution functions are reported. Highlights in the ongoing developments as well as the role of the input scale in parton analysis are discussed.

Speaker: Pedro Jimenez-Delgado (Jefferson Lab)

Proceedings 299-jimenez-delgado_pedro.pdf

Slides jimenez-delgadoSF.pdf

12:15 PM Uncertainties in Determining Parton Distributions at Large x: Results from the CJ Collaboration

The results of a global next-to-leading order fit of parton distribution functions in which cuts on W and Q are relaxed, thereby including more data at high values of x, will be reported. Effects of target mass corrections (TMC), higher twist contributions, and nuclear corrections for deuterium data are significant in the large-x region. The leading twist parton distributions are found to be stable to TMC model variations as long as higher twist contributions are also included. Importantly, uncertainties in parton distribution functions (PDFs) at large x arising from nuclear effects in deuterium F2 structure function data are evaluated. Within this global analysis, the impact on the PDFs from uncertainties in the deuteron wave function at short distances and nucleon off-shell effects, the use of relativistic kinematics, as well as the use of less a restrictive parametrization of the d/u ratio, have been assessed. In particular the d-quark and gluon PDFs are found to vary significantly with the choice of nuclear model. The impact of these uncertainties on the determination of the neutron structure function, and on W boson production and parton luminosity at the Tevatron and the LHC are highlighted. Prospects for new measurements sensitive to the d-quark and gluon distributions but insensitive to nuclear corrections will also be discussed.

Speaker: Cynthia Keppel (Hampton University)

Slides DIS2012_CJ_Keppel.pdf

12:35 PM An update on higher twist contributions to DIS structure functions

We report on a QCD re-analysis of the unpolarized non-singlet world data data in the valence region up to $O(\alpha_s^{3(4)})$ correlated to the value of the strong coupling constant $\alpha_s(M_Z2)$ and the higher twist contributions. We investigate contributions of twist $\tau = 3$ and higher to the polarized structure functions $g_1(x,Q2)$ and $g_2(x,Q2)$.

Speaker: Johannes Bluemlein (DESY)

Slides bluemleinSF.pdf

12:55 PM → 2:00 PM Lunch break

2:00 PM → 4:05 PM Combined: Future of DIS/spin physics

2:00 PM Status of TMDs and impact of an EIC

none

Speaker: Feng Yuan (LBL)

Proceedings 322-yuan_feng_2.pdf

Slides DIS12-TMD.pdf DIS12-TMD.ppt

2:25 PM Gluon sivers and experimental considerations for TMDs

none

Speaker: Tom Burton (BNL)

Proceedings 323-burton_thomas.pdf

Slides dis2012_burton.pdf

2:50 PM GPDs experimental

none

Speaker: Dr Salvatore Fazio (Brookhaven National Laboratory)

Proceedings 324-fazio_salvatore.pdf

Slides eRHIC_GPDs_DIS2012.pdf eRHIC_GPDs_DIS2012.pptx

3:15 PM Generalized parton distributions from present and future measurements

We discuss the access of generalized parton distributions (GPDs) from deeply virtual Compton scattering (DVCS) and deeply virtual meson production. We also illustrate that DVCS measurements at a future high-luminosity electron-ion-collider provide insight in both the transverse distribution of sea quarks and gluons as well as the proton spin decomposition.

Speaker: Dieter Mueller (BNL and Ruhr-University Bochum)

Proceedings 236-mueller_dieter.pdf

Slides Mueller-DIS12.pdf

3:40 PM Helicity PDFs at an EIC: quantitative appraisal

none

Speaker: Marco Stratmann (Univ. Regensburg/Univ. Wuerzburg)

Proceedings 326-stratmann_marco.pdf

Slides dis2012-stratmann.pptx

2:00 PM → 4:00 PM Diffraction and vector mesons

2:00 PM Central Exclusive Production in pp ̄ Collisions at CDF II

We report central exclusive production results studied at the Run II Collider Detector at Fermilab with focus on our recently published paper on the first observation of exclusive γγ production in pp ̄ collisions at √s = 1.96 TeV at the Tevatron. In particular, starting from earlier studies by the CDF collaboration, we discuss exclusive dijet, dilepton, Z, J/Ψ and χc productions and finally our recent observation of exclusive diphoton production. Whereas the lepton pairs and Z are purely QED processes, the J/Ψ is produced by photo-production, mediated by photon-pomeron exchange (γ + IP). The double pomeron exchange producing the exclusive dijet, Charmonium and diphotons via quark-loop is of great interest looking towards the possibilities of finding an exclusive Higgs at the Large Hadron Collider (if it exists). The production mechanism for an exclusive Higgs is similar via a heavy quark-loop with no other particles produced.

Speaker: Dr Erik Brücken (Helsinki Institute of Physics (FI))

Proceedings 254-brucken_erik.pdf

Slides dis_2012_cep_cdf.pdf

2:20 PM Exclusive dimuon production in the forward region with LHCb

We report on studies of exclusive dimuon production, using LHCb experimental data. Exclusively produced muon pairs can be produced by two photon fusion (a QED process ideally suited to obtaining a precise integrated luminosity measure), or by resonance production. We show results for exclusive dimuon production, and observations of the exclusive J/psi. psi‘ and chi_c states, obtained with data at $\sqrt(s) = 7$~TeV. We compare our results to predictions.

Speaker: Dermot Moran (Univ Manchester)

Proceedings 148-moran_dermot.pdf

Slides DermotMoran.pdf

2:40 PM Exclusive photon-photon processes in p-p collisions in CMS"

We present the search for exclusive diphoton production and the measurement of exclusive dilepton production, based on the data recorded by the CMS experiment at the LHC in 2010. An upper limit on the cross section is set for exclusive diphoton production, which is compared with the QCD perturbative theory predictions using different PDF sets. The exclusive dielectron production provides an excellent control sample for exclusive diphoton production, and a comparison between the measurement and the QED prediction is discussed. In addition, we report a measured cross section of exclusive dimuon production, which is compared with the theoretical QED prediction evaluated with the event generator LPAIR."

Speaker: Wenbo Li (Peking University (CN))

Proceedings 343-li_wenbo.pdf

Slides DISExclusiveProduction.pdf

3:00 PM News on Exclusive Production of the BSM Higgs Bosons

We investigate the prospects for Central Exclusive Diffractive (CED) production of BSM Higgs bosons at the LHC using forward proton detectors installed at 220~m and 420~m distance around ATLAS and / or CMS. We update a previous analysis for the MSSM taking into account improvements in the theoretical calculations and the most recent exclusion bounds from the LHC. We extend the MSSM analysis to new benchmark scenarios that are in agreement with the cold dark matter relic abundance and other precision measurements. Finally, we comment on the determination of Higgs spin-parity and coupling structures at the LHC and show that the forward proton mode could provide crucial information on the $\cp$ properties of the Higgs bosons.

Speaker: Dr Marek Tasevsky (Acad. of Sciences of the Czech Rep. (CZ))

Proceedings 262-tasevsky_marek.pdf

Slides CED_Higgs_270312.pdf CED_Higgs_270312.ppt

3:20 PM High energy exclusive leptoproduction of the rho-meson: theory and phenomenology

Exclusive leptoproduction of vector mesons has been the subject of recent significant progress, both theoretically and experimentally. In particular, the hard regime with a highly virtual photon exchange allows to separate a short distance dominated amplitude of hard subprocess from suitably defined hadronic objects. However, a consistent picture is still missing, in particular for contributions to the scattering amplitude beyond the leading power in the photon virtuality. We recently described the hard production of transversally polarized rho-meson, up to twist 3 accuracy, including 2- and 3- particles Fock-states, in the HERA kinematics of high center-of-mass energy. Furthermore, we here show how saturation effects could be included in our model. This is based on the dipole representation of the scattering amplitude in coordinate space, which we extend up to twist 3, based on our previous studies of the scattering amplitude in momentum space. We compare our model with H1 and ZEUS data for the ratios of helicity amplitudes T(gamma*T -> rhoT )/T(gamma*L -> rhoL) and T(gamma*T -> rhoL)/T(gamma*L -> rhoL) and get a good description of the data.

Speaker: Adrien Besse (L)

Proceedings 63-besse_adrien.pdf

Slides DIS2012-Besse.pdf

3:40 PM W, Z and jet central exclusive production at the LHC

We study the W/Z pair production via two-photon exchange at the LHC and give the sensitivities on trilinear and quartic gauge anomalous couplings between photons and W/Z bosons. Tagging the protons in the final state in the ATLAS Forward Physics detectors as an example allows to improve the reach on anomalous couplings by four orders of magnitude reaching the values predicted by extra-dimension theories. The measurement of the exclusive jet production using the same detectors at the LHC will also be described.

Speaker: Emilien Chapon (Centre d'Etudes de Saclay (CEN Saclay)-Unknown-Unknown)

Proceedings 218-chapon_emilien_1.pdf

Slides Chapon_DIS2012

2:00 PM → 4:00 PM Electroweak and searches

2:00 PM Some Z' and W' models facing current LHC searches

We present the implications of recent LHC results on some classes of Z' and W' models. We also remark how the strongest bounds (coming for example from searches for Z' -> dileptons and W' -> lepton + neutrino) do not apply to some theoretically motivated resonances, and discuss where signals from such states would appear.

Speaker: Ennio Salvioni (Universita e INFN (IT))

Proceedings 177-salvioni_ennio.pdf

Slides talk_salvioni_2.pdf

2:18 PM Searches for new physics with leptons and/or jets at CMS

Searches for new physics with leptons and/or jets at CMS

Speaker: Martin Weber (Rheinisch-Westfaelische Tech. Hoch. (DE))

Proceedings 221-weber_martin.pdf

Slides DIS2012-03-27-CMS_Searches_with_leptons_and_or_jets_MartinWeber.pdf

2:36 PM Searches for new physics with leptons and/or jets at ATLAS

We present the most recent results of searches beyond the Standard Model with leptons and /or jets conducted by the ATLAS collaboration based on several inverse femtobarns of data.

Speaker: Antonio Policicchio (INFN Cosenza)

Proceedings 199-policicchio_antonio.pdf

Slides policicchio_DIS2012.pdf

2:54 PM Searches for large extra dimensions, Leptoquarks and heavy quarks at CMS

Searches for large extra dimensions, Leptoquarks and heavy quarks at CMS

Speaker: Sushil Chauhan (University of California Davis (US))

Proceedings 222-chauhan_sushil.pdf

Slides chauhan.pdf

3:12 PM Search for heavy stable particles in CMS

Search for heavy stable particles in CMS

Speaker: Dr Loic Quertenmont (CERN)

Proceedings 223-quertenmont_loic.pdf

Slides Quertenmont_Loic.pdf

3:30 PM Searches for fourth generation heavy quarks with the ATLAS detector

The addition of one or more heavy quarks is a natural extension to the Standard Model. Fourth generation heavy quarks can be produced at the LHC at rates that can be observed in the 2011 data samples. The talk presents results from searches\'a0performed by the ATLAS collaboration for fourth generation quarks decaying via several potential decay channels.

Speaker: Jiahang Zhong (University of Oxford (GB))

Proceedings 200-zhong_jiahang.pdf

Slides JiahangZHONG_DIS2012.pdf

2:00 PM → 4:00 PM Hadronic final states

2:00 PM W/Z+jets measurements at D0

W/Z+jets measurements at D0

Speaker: Nikolai Skachkov (Joint Inst. for Nuclear Research (RU))

Slides W-Z-Jets-Bonn-final-DIS-2012.pdf W-Z-Jets-Bonn-final-DIS-2012.ppt

2:20 PM Z+Jets results from CDF

Inclusive Z boson plus jets cross sections, as well as bottom jet production in association with a Z-boson cross sections, are measured in a final state where the Z boson has decayed in two muons or electrons. Results are based on $\sim 9$ fb$ ^{-1}$ of data in $\rm p\bar{p}$ collisions at $\rm \sqrt{s}$ = 1.96 TeV collected with the CDF detector in Run II. Differential cross sections are measured as a function of several variables, among which jet transverse momentum, jet rapidity and jets multiplicity. Measurements are compared to results from different next-to-leading order perturbative QCD predictions and event generators.

Speaker: Lorenzo Ortolan

Proceedings 166-ortolan_lorenzo.pdf

Slides Ortolan_DIStalk.pdf

2:40 PM Studies of vector boson+jet production with ATLAS

The production of jets in association with a W or Z boson in proton-proton collisions at 7 TeV is an important process to understand in QCD. 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 measured. In addition, the cross sections for vector bosons produced with bottom jets, Z+b-jet and W+b-jet, have been measured and compared to NLO QCD calculations. Overall, the cross sections demonstrate the need for the inclusion of higher-multiplicity matrix elements in the calculations, even in cases where a parton shower simulation is present.

Speaker: Camille Belanger-Champagne (McGill University (CA))

Proceedings 82-belanger-champagne_camille.pdf

Slides 20120327_dis_champagnev2(3).pdf

3:00 PM W+n-jet predictions at NLO matched with a parton shower

The MC@NLO method as implemented in the Sherpa MC generator is presented using the production of W-bosons in conjunction with up to three jets as an example. Corresponding results computed at next-to leading order in QCD and including parton shower corrections are compared to recent experimental data from the Large Hadron Collider.

Speaker: Frank Siegert (Albert-Ludwigs-Universitaet Freiburg (DE))

Proceedings 242-siegert_frank.pdf

Slides FSiegert.pdf

3:20 PM Matching Tree-Level Matrix Elements with Interleaved Showers

We present the recent implementation of CKKW-L merging inside Pythia8, and comment on the treatment of multiparton interactions in the context of matrix element merging. Since multiple interactions inside Pythia8 are fully interleaved with space- and time-like showers, care has to be taken when allowing for MPI. Further, we will discuss the uncertainties of the implementation.

Speaker: Stefan Prestel (L)

Slides SPrestel.pdf

3:40 PM Subleading N-colour improved Parton Showers

Parton shower Monte Carlos are by now standard tools to simulate hadronic final states. Having seen a tremendous improvement of combining parton showers and fixed order calculations in recent years, efforts are now underway to improve the shower approximations themselves, as well. In this contribution we will present first steps towards including subleading colour contributions into parton shower algorithms and discuss the impact of these corrections. Technical aspects required to arrive at such an improved algorithm, particularly generalizations of the Sudakov veto algorithm, will also be discussed.

Speaker: Simon Plaetzer (DESY Hamburg)

Proceedings 234-platzer_simon.pdf

Slides SPlatzer.pdf

2:00 PM → 4:10 PM Heavy flavours

2:00 PM Charm fragmentation fractions in Photoproduction

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. The obtained fractions can be compared to previous results from HERA and to measurements from e+e- experiments.

Speaker: Ganna Dolinska (Kiev University)

Proceedings 47-dolinska_ganna.pdf

Slides Dolinska_DIS2012.pdf

2:18 PM Soft-gluon resummation in heavy top-pair production at hadron colliders

The current state of the art in top-pair production is based on threshold resummation on top of the exact NLO result. We will examine the role - and the limitations - of the soft-gluon approximation in describing precision top-pair production at hadron colliders. We will demonstrate that the only way to substantially improve our knowledge of this observable is through fixed order calculation at NNLO. The status of this ongoing calculation will also be presented.

Speaker: Alexander Mitov (CERN)

Slides AlexanderMitov-DIS-HF-2012.pdf AlexanderMitov-DIS-HF-2012.pptx

2:36 PM Differential and total cross sections for top pair and single top production

I present theoretical results at approximate NNLO for top quark production at the LHC at 7 and 8 TeV energy. Total cross sections are shown for ttbar production and single top production in the t and s channels and via associated tW production.Top quark transverse momentum and rapidity distributions are also presented.

Speaker: Nikolaos Kidonakis (Kennesaw State University)

Proceedings 251-kidonakis_nikolaos.pdf

Slides Kidonakis-top.pdf

2:54 PM ATLAS: Top quark pair production cross-section

We present measurements of the production of top quarks in proton-proton collisions at 7 TeV with the ATLAS detector at the Large Hadron Collider. The cross section of pair-produced top quarks is measured in several channels, including the single lepton, dilepton and all hadronic channel, some using information from b-tagging.

Speaker: Kate Shaw (Abdus Salam Int. Cent. Theor. Phys. (IT))

Proceedings 89-shaw_kate.pdf

Slides topPairProduction_KShaw.pdf

3:12 PM CMS: Measurements of total and differential top-production cross sections

We present precise measurements of the top quark pair production cross section at 7 TeV, performed using CMS data collected in 2010-2011. The total cross section is measured in the lepton+jets, dilepton and fully hadronic channels, including the tau-dilepton and tau+jets modes. The results are combined and confronted with precise theory calculations. We also obtain an indirect constraint on the top quark mass through its relation to the cross section. Various differential cross sections are measured as well and compared with theoretical models. Measurements of the top pair invariant mass distribution are used to search for new particles decaying to top pairs. Further results include measurements of the top pair charge asymmetry and single top production.

Speaker: Antonio Tropiano (Universita e INFN (IT))

Proceedings 257-tropiano_antonio.pdf

Slides top_cms.pdf

3:30 PM Top quark production at D0

We present measurements of the cross sections for the production of top-antitop quark pair production via the strong interaction and for the production of single top quarks via the weak interaction in proton-antiproton collisions at sqrt(s)=1.96 TeV using data corresponding to integrated luminosities of up to 5.4 fb-1. The data were collected with the D0 detector at the Fermilab Tevatron collider. For the top-antitop pair production, measurements are obtained from the study of the kinematic properties and of the b-tagging rates in final states for with either a charged lepton pair accompanied by additional jets and missing transverse momentum, and in final states with one charged lepton, three or more jets and missing transverse momentum. For the single top quark production the measurement is obtained from the final states with one charged lepton, at least two jets and missing transverse momentum, and studies of the relative contributions of different production mechanisms are also presented. Finally we present measurements of the forward-backward asymmetry in the top-antitop quark final states.

Speaker: Karel Soustruznik (C)

Proceedings 205-soustruznik_karel.pdf

Slides dis12_soustruz_v2a.pdf

3:48 PM Top quark physics in CDF

The study of the dynamics of top-quark pair production in proton-proton and proton-antiproton collisions plays an important role in the understanding of parton interactions at large Bjorken-x. It tests the assumptions of the standard model and of quantum chromodynamics at the electroweak scale and beyond. The CDF data set is an ideal sample for measuring observables sensitive to the dynamics of top-quark pair production, given the excellent understanding of detector performance and the unique proton-antiproton initial state. We present recent measurements of such observables from CDF. These include the direct measurement of the ratio R of the branching fraction of top-quark decaying to W + b-quark over the branching fraction of top-quark decaying to W + any quark flavor. The measurement uses data corresponding to 7.5/fb of integrated luminosity in the lepton+jets decay channel. The ratio R constrains the |V_tb| element of the CKM matrix. We also present a measurement of the spin correlation coefficient of the top-quark pair, which can be directly measured uniquely in the top-pair system thanks to the very short life time of the top-quark. This measurement uses data corresponding to 5.1/fb of integrated luminosity in the dilepton decay channel. Finally, we present a study of the top-quark pair production asymmetries in the lepton+jets channel using the full CDF Run II data set which corresponds to an integrated luminosity of 8.7/fb. The study includes the measurement of the cross section differential in the top-pair rapidity difference, the measurement of the inclusive forward-backward asymmetry A_FB, as well as the measurement of A_FB as a function of the rapidity difference and of the invariant mass of the top-pair system. The production asymmetries are sensitive to the top-quark pair production mechanism, thus constraining quantum chromodynamics at higher order and testing for possible new physics.

Speaker: Konstantinos Vellidis (University of Athens (GR))

Proceedings 204-vellidis_konstantinos_2.pdf

Slides cdf_top_dis2012.pdf

2:00 PM → 4:00 PM Structure functions

2:00 PM Progress in CTEQ-TEA PDF analysis

I discuss latest developments in the CTEQ-TEA PDF analysis: NNLO PDFs, benchmarking of NLO and NNLO cross sections included in the global fits, analysis of constraints on PDFs with the method of PDF-induced correlations.

Speaker: Pavel Nadolsky (Southern Methodist University)

Proceedings 301-nadolsky_pavel.pdf

Slides c327.pdf

2:25 PM Global Analysis of Nuclear Parton Distributions

We present a new global QCD analysis of nuclear parton distribution functions and their uncertainties. In addition to the most commonly analyzed data sets for deep inelastic scattering of charged leptons off nuclei and Drell-Yan di-lepton production, we include also measurements for neutrino nuclei scattering as well as inclusive pion production in deuteron gold collisions. The analysis is performed at next-to-leading order accuracy in perturbative QCD in a general mass variable flavor number scheme, adopting a current set of free nucleon parton distribution functions, defined accordingly, as reference. The emerging picture is one of consistency, where universal nuclear modification factors for each parton flavor reproduce the main features of all data without any significant tension among the different sets. We use the Hessian method to estimate the uncertainties of the obtained nuclear modification factors and examine critically their range of validity in view of the sparse kinematic coverage of the present data. We briefly present several applications of our nuclear parton densities in hard nuclear reactions at BNL-RHIC, CERN-LHC, and a future electron ion collider.

Speaker: Rodolfo Sassot (Universidad de Buenos Aires)

Proceedings 33-sassot_rodolfo.pdf

Slides sassot_DIS2012.pdf

2:45 PM An update and comparison of global NPDF analyses

A global NPDF analysis of the combined charged-lepton DIS, DY and neutrino DIS data finds a tension between the nuclear correction factors in nA DIS and ℓA DIS. We explore possible sources of this tension by comparing the input PDFs used by different nuclear global fitting groups, and also compute ratios of experimental observables which (largely) minimize any theoretical bias. We also show comparisons with recent nPDF determinations. This work helps to isolate the sources of possible tensions in the extracted nuclear corrections.

Speaker: Karol Kovarik (University of Karlsruhe)

Proceedings 155-kovarik_karol_2.pdf

Slides DISnpdf-kovarik.pdf

3:05 PM Using the BFKL resummation to fit DIS data: collinear and running coupling effects

The proton structure function F_2 is studied in the low x regime using BFKL evolution instead of the usual DGLAP approach, suited for large values of the DIS x variable. The NLL analysis requires the inclusion of running coupling effects which lead to off-diagonal terms in the BFKL kernel that need to be treated carefully. We also introduce an all-orders resummation that improves the collinear behavior of the NLL BFKL result. This study is presented emphasizing the theoretical uncertainties that appear throughout the analysis and a comparison with the combined HERA data is given.

Speaker: Clara Salas (IFT, Madrid)

Proceedings 97-salas_clara_1.pdf

Slides Clara_Salas_F2.pdf

3:25 PM Determination of CCFM uPDF with combined HERA data

We present a new determination of the un-integrated PDF using the combined HERA data. We obtain acceptable chi*2/ndf. We find that for a good description of HERA data the gluon splitting function including non-singular terms as well as kinematic constraints and NLO alphas are necessary. We determine for the first time a full set of uncertainty uPDFs which allow to study the uPDF uncertainty for processes at HERA and the LHC. We also show a comparison of predictions using the new uPDFs with measurements from HERA and the LHC.

Speaker: Hannes Jung (Deutsches Elektronen-Synchrotron (DE))

Proceedings 29-jung_hannes.pdf

Slides updfs-CCFM.pdf

4:10 PM → 4:30 PM Coffee break

4:30 PM → 6:00 PM Diffraction and vector mesons

4:50 PM Measurements of hard diffraction in p-p collisions in CMS

The talk will present CMS measurements on diffractive W and dijet production in p-p collisions at 0.9, 2.36 and 7 TeV.

Speaker: Antonio Vilela Pereira (Universita e INFN (IT))

Proceedings 342-vilelapereira_antonio.pdf

Slides VilelaPereira_HardDiffractionCMS_DIS2012_draft_v260312_v2.pdf

5:10 PM Probing the Low-x Structure of the Nucleus with the PHENIX Detector

One of the fundamental goals of the PHENIX experiment is to understand the structure of cold nuclear matter, since this serves as the initial state for heavy-ion collisions. Knowing the initial state is vital for interpreting measurements from heavy-ion collisions. Moreover, the structure of the cold nucleus by itself is interesting since it is a test-bed for our understanding of QCD. In particular there is the possibility of novel QCD effects such as gluon saturation at low-x in the nucleus. At RHIC we can probe the structure of cold nuclear matter using d+Au collisions. We will present measurements of forward di-hadron correlations and inclusive J/Psi production, which seem to show some interesting effects in the cold nucleus, especially as one probes down to Bjorken x of about $10^{-3}$ in the Au nucleus.

Speaker: Dr Mickey Chiu (Brookhaven National Lab)

Proceedings 133-chiu_mickey.pdf

Slides chiu_dis2012.ppt

5:30 PM Diffractive pQCD mechanisms of exclusive production of $b \bar b$ dijets and $W^+ W^-$ pairs in proton-proton collisions

We discuss central exclusive production of $W^+W^-$ pairs in proton-proton collisions at LHC. Several observables related to this process are calculated. Predictions for the total cross section and differential distributions in rapidity and transverse momentum of $W^{\pm}$ and $WW$ invariant mass are presented. We show results for different polarization states of the final $W^{\pm}$ bosons. We discuss both $\gamma \gamma \to W^+ W^-$ mechanism as well as a new mechanism of exclusive diffractive production. The amplitude for the latter process is calculated in the Durham model used recently to estimate cross section for exclusive production of Higgs boson, gluon-gluon, $b \bar b$ dijets as well as for pairs of photons. Some results for those processes will be discussed briefly and compared to the CDF collaboration data. The amplitude for the $p p \to p p W^+ W^-$ process is expressed in terms of off-diagonal unintegrated gluon distribution functions. We compare the two (QED and QCD) types of contributions. The phase space integrated diffractive contribution when separated is only a small fraction of fb compared to 115.4 fb of the $\gamma \gamma$ contribution. The $\gamma \gamma$ contribution dominates at small four-momentum transfers squared in the proton lines as well as in a broad range of $W^+ W^-$ invariant masses. This opens a possibility of searches for anomalous four-boson $\gamma \gamma W^+ W^-$ coupling due to new physics beyond Standard Model. The example are Higgsless models. The presentation will be based mostly on our recent study. I will also show some published results on exclusive production of Higgs and dijets.

Speaker: Prof. Antoni Szczurek (Institute of Nuclear Physics Krakow (Poland))

Proceedings 261-szczurek_antoni_2.pdf

Slides szczurek_dis2012_WW.pdf

4:30 PM → 6:00 PM Electroweak and searches

4:30 PM Measurement of the neutrino velocity with the OPERA detector in the CNGS beam

The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km with much higher accuracy than previous studies conducted with accelerator neutrinos. The measurement is based on high-statistics data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies.

Speaker: Torben Ferber (Hamburg University)

Slides dis2012_ferber_v4.pdf

4:48 PM A theoretical review of the implications of recent OPERA results

We review the theoretical implications of the OPERA results, with particular emphasis on the consistency with other tests of special relativity (directly or through quantum effects in the charged lepton sector) and the difficulties in construction of models satisfying all constraints.

Speaker: Sergey Sibiryakov (Institute for Nuclear Research of RAS)

Slides DIS12.pdf

5:06 PM Searches at H1

Merged abstract of: "Search for Contact Interactions in ep Collisions at HERA" "Search for First Generation Leptoquarks in ep Collisions at HERA"

Speaker: Hayk Pirumov (PI Heidelberg)

Slides pirumov_270312.pdf

5:24 PM Searches at ZEUS

Merged abstract of: "Search for Single-Top Production in ep Collisions at HERA" "A search for resonance decays to lepton+jet at HERA and limits on leptoquarks"

Speaker: Stefano Antonelli (Universita e INFN)

Proceedings 294-antonelli_stefano.pdf

Slides searches_at_zeus_dis2012.pdf

5:42 PM Results from NA48 and NA62

Merged abstract: "High precision measurement of the form factors of the semileptonic decays K+- -> pi0 l+- nu (Kl3)" "Rare kaon decay measurements with NA62 minimum bias data." "First Measurement of the very rare Decay K+ -> pi+ pi0 e+ e-" "Lepton Universality Tests in Kaon Decays at NA62"

Speaker: Mauro Piccini (Universita e INFN (IT))

Proceedings 295-piccini_mauro.pdf

Slides piccini.pdf

4:30 PM → 6:15 PM Future of DIS

4:30 PM Status of HallD tagged photon beam facility and the GlueX detector

Speaker: Benedikt Zihlmann (J)

Slides zihlmann_dis2012.pdf

4:55 PM The CLAS12 Physics Program

With the doubling of the Jefferson Lab beam energy and the complete rebuilding of the CLAS spectrometer underway, a full experimental program is already approved for Hall B. The components of this program relevant to deep-inelastic scattering will be discussed.

Speaker: Keith Griffioen (C)

Slides GriffioenDIS2012.pdf

5:20 PM Precision Polarized SIDIS Experiments in Hall-A at 12 GeV JLab

One of the cleanest ways to access the Transverse Momentum Dependent (TMD) parton distribution functions of the nucleon is to measure single (SSA) and double spin asymmetries (DSA) in semi-inclusive DIS reactions using polarized nucleon targets. The Jefferson Lab 12 GeV upgrade will provide a unique opportunity to perform such precision measurements and to map these multi-dimensional PDFs. In this talk, we will present our plans for performing these precision measurements in Hall-A using Large acceptance SoLID spectrometer and polarized proton and 3 He (neutron) targets. In particular, we will focus on two approved A-rated experiments using both longitudinally and transversely polarized 3 He targets, and a conditionally approved experiment with a transversely polarized proton target. The high luminosities from these targets and the large acceptance of the SoLID spectrometer will allow for a precise 4-dimensional (x, Q2 , z, PT ) mapping of SSA and DSA. The full azimuthal angular coverage is necessary to untangle various angular moments and thereby reduce the systematic uncertainties. These experiments will provide the most precise data to extract transversity, Sivers and Worm-gear distributions of u and d-quarks and provide comprehensive information on the correlation between quark angular momentum and the nucleon’s spin.

Speaker: Mr Kalyan Allada (Jefferson Lab)

Proceedings 140-allada_kalyan.pdf

Slides KalyanAllada_DIS2012.pdf

4:30 PM → 6:30 PM Hadronic final states

4:30 PM Towards parton shower to 2 to 2 matrix element matching in kt-factorisation

We present a subtraction method for including next to leading order corrections to a 2 to 2 jet production process in kt-factorisation equivalent to a jet matching procedure in Monte Carlo generators. We study the improvement in soft cut dependance.

Speaker: Dr Michal Deak (Universidade de Santiago de Compostela)

Proceedings 1-deak_michal_2.pdf

Slides DIS2012-Deak.pdf

4:50 PM Drell-Yan lepton pair production in the kt-factorization approach

In the framework of the kt-factorization approach, the production of unpolarized Drell-Yan lepton pair at high energies is studied. The consideration is based on the O(alpha) and $O(alpha alpha_s) off-shell partonic matrix elements with virtual photon and Z boson exchange. The calculations include leptonic decays of Z bosons with full spin correlations as well as gamma - Z interference. The unintegrated parton densities in a proton are determined by the Kimber-Martin-Ryskin prescription. Our numerical predictions are compared with the data taken by the D0, CDF and CMS collaborations at the Tevatron and LHC energies. Special attention is put on the specific angular distributions measured very recently by the CDF collaboration for the first time.

Speaker: Mr Maxim Malyshev (SINP MSU)

Proceedings 3-malyshev_maxim.pdf

Slides malyshev_drell-yan.pdf

5:10 PM Electroweak Gauge-Boson and Higgs Production at Small qT : Infrared Safety from the Collinear Anomaly

We discuss the differential cross sections for electroweak gauge-boson and Higgs production at small and very small transverse momentum q_T. Large logarithms are resummed using soft-collinear effective theory. The collinear anomaly generates a non-perturbative scale q^∗, which protects the processes from receiving large long-distance hadronic contributions. A numerical comparison of our predictions with data on the transverse-momentum distribution in Z-boson production at the Tevatron and LHC is given.

Speaker: Daniel Wilhelm (Mainz U)

Proceedings 314-wilhelm_daniel.pdf

Slides v0004_-_DIS_2012.pdf

5:30 PM Quark and Gluon Tagging at the LHC

Distinguishing light-quark jets from gluon jets on an event-by-event basis could significantly enhance the reach for many new physics searches at the Large Hadron Collider. Through an exhaustive search of existing and novel jet substructure observables, we find that a multivariate approach can filter out over 95% of the gluon jets while keeping more than half of the light-quark jets. Moreover, a combination of two simple variables, the charge track multiplicity and the p_T-weighted linear radial moment (girth), can achieve similar results. I will discuss applications and address theoretical issues in the definitions of quark and gluon jets.

Speaker: Jason Gallicchio (UC Davis)

Slides JGallicchio.pdf

5:50 PM Normalised Multi-jet Cross Sections using Regularised Unfolding and Extractions of alpha_s(M_Z) in Deep-Inelastic Scattering at high Q^2 at HERA (H1)

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 of this measurement with the H1 detector is given by the virtuality of the exchanged boson (gamma*,Z^0) 150 < Q^2 < 15000 GeV^2 and the inelasticity of the interaction 0.2 < y < 0.7. The jets are reconstructed in the Breit frame of reference using the k_t jet algorithm. In all cases the jet pseudorapidities in the laboratory frame are required to be in the range -1.0 < eta_lab < 2.5. For inclusive jets the transverse momenta in the Breit frame are 7 < P_T < 50 GeV. The di-jet and tri-jet phase space are defined by requiring 5 < P_T,i < 50 GeV, and the invariant mass of the two leading jets M_1,2 > 16 GeV. Compared to a previously published result on normalised multi-jet cross sections, the new features are an extended range in jet pseudorapidity, an improved hadronic energy scale uncertainty of 1% and the adoption of a regularised unfolding procedure. The unfolded normalised jet cross sections are compared to QCD calculations at NLO and values for the strong coupling alpha_s(M_Z) are extracted.

Speaker: Daniel Andreas Britzger (Ludwig-Maximilians-Universitat Munchen)

Proceedings 163-britzger_daniel_1.pdf

Slides 120327_NormMultijets_DIS12_final.pdf

6:10 PM Inclusive-Jet Photoproduction at HERA

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 jet transverse energy, Etjet. In addition, measurements of double-differential inclusive-jet cross sections are presented as functions of Etjet in different regions of etajet. These cross sections have the potential to constrain the gluon density in the proton and the photon when included as input to fits to extract the proton parton distribution functions. Next-to-leading-order QCD calculations give a good description of the measurements. A value of alphas(Mz) has been extracted from the measurements. The energy-scale dependence of the coupling has also been determined.

Speaker: ewald paul (P)

Proceedings 43-paul_ewald.pdf

Slides Paul_DISvortrag.pdf

4:30 PM → 6:00 PM Heavy flavours

4:30 PM ATLAS top quark mass measurement

We present a measurement of the top-quark mass in proton-proton collisions at 7 TeV with the ATLAS detector at the Large Hadron Collider. The top mass is determined by making use of a two-dimensional template method in the single lepton channel. An indirect extraction of the top-quark mass from the measurement of the cross-section is also presented.

Speakers: Christian Andreas Jung (TU Dortmund), Christian Andreas Jung (Technische Universitaet Dortmund (DE))

Proceedings 91-jung_christian.pdf

Slides dis_cjung.pdf

4:48 PM D0 top mass and properties

Merged abstract: "Measurement of the top quark mass at D0" "Measurements of top quark properties at D0"

Speakers: Tim Head (The University of Manchester), Timothy Head (University of Manchester)

Proceedings 310-head_tim.pdf

Slides head-top-properties.pdf

5:06 PM ATLAS top quark properties

Merged abstract: "Top quark properties" "Top quark pair properties"

Speakers: Minoru Hirose (Osaka University (JP)), Minoru Hirose (Osaka University)

Proceedings 308-hirose_minoru.pdf

Slides DIS2012_v9.pdf

5:24 PM Top-quark pair-production with one jet and parton showering at hadron colliders

We discuss heavy-flavor production in association with one jet hadronic collisions matched to parton shower Monte Carlo programs at next-to-leading order QCD with account of top-quark decays and spin correlations in the decay products. The calculation builds on existing results for the radiative corrections to heavy-quark plus one jet production and uses the POWHEG BOX for the interface to the parton shower programs PYTHIA or HERWIG. Phenomenological studies for the LHC and the Tevatron are presented. In particular we study the impact of the parton shower on the top-quark charge asymmetry.

Speaker: Sven-Olaf Moch (Unknown)

Proceedings 231-moch_sven-olaf.pdf

Slides moch.pdf

5:42 PM Top--antitop quark + X hadroproduction at NLO accuracy with decay and evolution to the hadron level

Aiming at better understanding of the properties of top quarks, we focus on top--antitop+X production at the LHC, with X being a vector, or scalar/pseudoscalar boson. We show predictions obtained by PowHel, a computing framework based upon the POWHEG-BOX program with input obtained from HELAC-NLO. The POWHEG-BOX generates event files according to the Les-Houches accord, and uses the POWHEG matching formalism to further evolve these events to the hadron level ready for use in any experimental analysis. We discuss the sensitivities of our predictions to the choice of the Shower Monte Carlo code (PYTHIA vs. HERWIG). We show examples of how the choice of different experimental cuts and/or heavy particle reconstruction strategies can affect the predictions and help disentangle our signals from important backgrounds, also involving top-quark production and decay.

Speaker: Adam Kardos (University of Debrecen)

Proceedings 232-kardos_adam.pdf

Slides kardos.pdf

4:30 PM → 6:00 PM Spin physics

4:30 PM Recent STAR results and future prospects of the W boson program at RHIC at BNL

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 completion of the first $\sqrt{s}=500\,$GeV polarized proton run in 2009 opened a new era of spin-flavor structure measurements from $W^{-(+)}$ boson production. $W^{-(+)}$ bosons are produced in $\bar{u}+d\,(\bar{d}+u)$ collisions and can be detected through their leptonic decays, $e^{-}+\bar{\nu}_{e}\;(e^{+}+\nu_{e})$, where only the respective charged lepton is measured. The discrimination of $\bar{u}+d\;(\bar{d}+u)$ quark combinations requires distinguishing between high $p_{T}$ $e^{-(+)}$ through their opposite charge sign, which in turn requires precise tracking information. Recent published STAR results on the first measurement of $W^{-}/W^{+}$ and $Z$ boson production will be shown. The STAR experiment has recently started the installation of the Forward GEM Tracker to enhance the charge separation of high $p_{T}$ $e^{-(+)}$ at forward pseudorapidities and will begin the commissioning of this new tracking system during the upcoming 2012 running period. The status of the Forward GEM Tracker along with a discussion of future prospects will be presented.

Speaker: Prof. Bernd Surrow (MIT)

Slides DIS2012-BSurrow.pdf

5:00 PM NNPDF determination of polarized parton distributions of the nucleon at NLO

We present a preliminary determination of a set of polarized parton distributions of the nucleon, at next-to-leading order, from a global set of deep-inelastic scattering data. The determination is based on the NNPDF methodology: a Monte Carlo sampling with neural networks used as unbiased interpolants. This method, which has already been applied to a determination of unpolarized parton distributions, is designed to provide a faithful and statistically sound representation of the uncertainty on parton distributions. We discuss the general NNPDF procedure to parton fitting, focusing on the algorithm used to determine the optimal fit. We also present a preliminary set of polarized PDFs, compared to other parton extractions recently obtained by other collaborations. In particular, we show that "traditional" fits tend to underestimate the PDF uncertainty, particularly for the gluon, which is basically unconstrained by inclusive DIS data.

Speaker: Emanuele Roberto Nocera (Universita degli Studi di Milano and INFN, Milano)

Proceedings 273-nocera_emanueleroberto.pdf

Slides DIS2012_nocera.pdf

5:20 PM Longitudinal semi-inclusive double-spin asymmetries at HERMES.

Final measurements are reported on the double-spin asymmetries for a longitudinally polarized hydrogen and deuterium targets at HERMES using the27.6 GeV HERA lepton beam. The kinematic dependences of the longitudinal semi-inclusive asymmetry simultaneously on Bjorken-x and hadron transverse momentum p_h, and Bjorken-x and the hadron energy fraction z are explored. Additionally, the hadron charge-difference asymmetry is presented, which under certain model assumptions grants access to the parton distributions of the valence quarks.

Speaker: Dr Polina Kravchenko (DESY)

Proceedings 117-kravchenko_polina.pdf

Slides DIS12_v2.pdf

5:40 PM $W$ Physics in Polarized Proton-Proton Collisions at PHENIX

A major direction of the physics program at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is to explore the origin of proton spin structure. Parity violating single spin asymmetries, $A_L$, for $W$-bosons in longitudinally polarized $p + p$ collisions at a center of mass energy of $\sqrt{s}$ = 500 GeV will give access to the flavor separated quark and anti-quark polarization distributions for up- and down-quarks in the proton. The PHENIX collaboration has measured $A_L$ for electrons from $W$-decay in the central rapidity region, $-0.35 < \eta < 0.35$ based on a data sample taken in 2009. A second data sample taken in 2011 is being used to measure $A_L$ for $W$-decays into muons with two PHENIX forward muon spectrometers covering $1.2 < |\eta| < 2.4$. Cross sections for $W^\pm$-boson production at central rapidity and the corresponding single spin asymmetries will be presented. The cross sections will be compared with similar measurements at LHC. The upgrade effort directed at $W$-physics in the muon spectrometers just has been completed. The new instrumentation will be briefly described and the the status of the $W$-analysis in the PHENIX muon spectrometers will be discussed.

Speaker: Young Jin Kim (University of Illinois at Urbana-Champaign)

Slides DIS_2012_yjkim.pdf

4:30 PM → 6:15 PM Structure functions

4:30 PM Photon impact factor for BFKL pomeron at next-to-leading order

I will present an analytic expression in momentum space of the next-to-leading order photon impact factor for small-x deep inelastic scattering. The result is calculated using the operator product expansion in Wilson lines.

Speaker: Giovanni Antonio Chirilli (Lawrence Berkeley National Laboratory (LBNL))

Proceedings 128-chirilli_giovanni.pdf

Slides DIS-2012-Mar-27-Chirilli.pdf

4:45 PM Low x physics: a critical phenomenon?

The DIS structure functions are expressed, in a rigorous way, as correlation functions in a quantum field theory containing a parameter r. It is shown that low x physics corresponds to the theory in the limit of r going to zero where the theory develops a large correlation length. This indicates critical behaviour. The data on F2 are analysed in a geometric way and values for the critical indices are extracted.

Speaker: Prof. Otto Nachtmann (Institute for Theoretical Physics, University of Heidelberg)

Proceedings 118-nachtmann_otto.pdf

Slides Nachtmann_2012_03_19_Bonn.pdf

5:00 PM The Recent F_L Measurement from HERA and the Dipole Model

From the new measurement of F_L at HERA we derive fixed-Q^2 averages <F_L/F_2>. We compare these with bounds which are rigorous in the framework of the standard dipole picture. The bounds are sharpened by including information on the charm structure function F_2^(c). Within the experimental errors the bounds are respected by the data. But for 3.5 GeV^2 <= Q^2 <= 20 GeV^2 the central values of the data are close to and in some cases even above the bounds. Data on F_L/F_2 significantly exceeding the bounds would rule out the standard dipole picture at these kinematic points. We discuss, furthermore, what can be learned from data respecting the bounds but coming close to them.

Speaker: Carlo Ewerz (ExtreMe Matter Institute EMMI, GSI, and Heidelberg University)

Slides dis2012-carlo-ewerz.pdf

5:20 PM Nonlinear equation for coherent gluon emissions

Motivated by the explored nowadays at LHC the regime of QCD where both the total energy of collision and momenta transfers are high, we investigate evolution equations of high energy factorization. In order to study such effects like parton saturation in final states one is inevitably lead to investigate how to combine physics of the BK and CCFM evolution equations. In this letter we obtain a new exclusive form of the BK equation which suggests a possible form of the nonlinear extension of the CCFM equation.

Speaker: Krzysztof Kutak (I)

Proceedings 31-kutak_krzysztof_1.pdf

Slides kutak_DIS.pdf

5:35 PM The statistical model for parton distributions

First we recall the basic physical features of the parton distribution functions (PDF) in the quantum statistical approach of the nucleon. Several predictions from next-to-leading QCD calculations using these PDF are compared with recent experimental results: deep inelastic scattering from HERA, hadronic reactions from Tevatron and RHIC, neutrino data and also polarized data obtained by Compass at CERN and by the polarized pp collider at BNL.

Speaker: Franco Buccella (Unknown)

Proceedings 95-buccella_franco.pdf

Slides DIS-bonn-buccella.pdf

Wed, March 28

8:30 AM → 10:10 AM Combined: Hadronic final states/diffraction and vector mesons

8:30 AM Jet reconstruction with LHCb

Speakers: Albert Bursche (University of Zurich), Albert Bursche (Universitaet Zuerich (CH))

Proceedings 146-bursche_albert.pdf

Slides ABursche.jets.pdf

8:50 AM Measurement of Photon Production in the Very Forward Direction in Deep-Inelastic Scattering at HERA [H1]

The production of photons at very small angles with respect to the proton beam direction is studied in deep-inelastic positron-proton scattering at HERA. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $126 \mathrm{pb}^{-1}$. The analysis covers the range of negative four momentum transfer squared at the positron vertex $6<Q^2<100$ GeV$^2$ and inelasticity $0.05<y<0.6$. Cross sections are measured for the most energetic photon with pseudorapidity $\eta>7.9$ as a function of its transverse momentum $p_T^{lead}$ and longitudinal momentum fraction of the incoming proton $x_L^{lead}$. In addition, the cross sections are studied as a function of the sum of the longitudinal momentum fraction $x_L^{sum}$ of all photons in the pseudorapidity range $\eta>7.9$. The cross sections are normalised to the inclusive deep-inelastic scattering cross section and compared to the predictions of models of deep-inelastic scattering and models of the hadronic interactions of high energy cosmic rays.

Speaker: Hamlet Zohrabian

Proceedings 58-zohrabyan_hamlet.pdf

Slides Dis2012.hamlet.z.pdf

9:10 AM Measurement of the Azimuthal Correlation between the most Forward Jet and the Scattered Positron in Deep-Inelastic Scattering at HERA [H1]

Deep-inelastic positron-proton scattering events at low photon virtuality Q^2 with a forward jet, produced at small angles with respect to the proton beam, are measured with the H1 detector at HERA. A subsample of events with an additional jet in the central region is also studied. For both samples differential cross sections and normalised distributions are measured as a function of the azimuthal angle difference, Delta phi, between the forward jet and the scattered positron. The sensitivity to QCD evolution mechanisms is tested by comparing the data to predictions of Monte Carlo generators based on different evolution approaches as well as to next-to-leading order calculations.

Speaker: Lidia Goerlich (High Energy Department-Henryk Niewodniczanski Inst. Nucl. Physic)

Proceedings 59-goerlich_lidia.pdf

Slides goerlich_dis2012_[tryb_zgodności].pdf

9:30 AM Forward Jets and Small-x Physics at the LHC

We discuss QCD aspects of forward jet hadroproduction, including issues on factorization at large rapidities; shower Monte Carlo implementations; the role of forward jet and energy flow measurements at the LHC to investigate contributions to parton showers from large-angle gluon radiation and from multiple parton interactions.

Speaker: Francesco Hautmann (University of Oxford (GB))

Proceedings 271-hautmann_francesco.pdf

Slides tk_dis12_mar28.pdf

9:50 AM Probing colour flow with jet vetoes

I discuss jet vetoes as a means of probing colour flow in hard scattering processes in hadronic collisions. As an example, I describe a calculation of the dijet cross-section with a jet veto which resums the leading logarithms of the veto scale and it is matched to a fixed-order computation. I compare this prediction to the measurement performed by the ATLAS collaboration as well as to other different approaches. Finally, I outline future developments in this research area.

Speaker: Simone Marzani (IPPP / Durham University)

Proceedings 264-marzani_simone.pdf

Slides marzaniDIS2012veto.pdf

8:30 AM → 10:00 AM Combined: Heavy flavours/structure functions

8:30 AM New Heavy Flavor Contributions to the DIS Structure Function F_2(x,Q2) at O(\alpha_s3)

We report on recent results obtained for the massive Wilson coefficients which contribute to the structure function $F_2(x,Q2)$ at $O(\alpha_s2)$ and $O(\alpha_s3)$ in the region $Q2/m2 \gsim 10$ for general values of the Mellin variable $N$ as well as to corresponding operator matrix elements emerging in FVNSs.

Speaker: Johannes Bluemlein (DESY, Zeuthen)

Proceedings 252-bluemlein_johannes_1.pdf

Slides Bluemlein_BONN2.pdf

8:50 AM Heavy Quark Production in the ACOT Scheme at NNLO and N3LO

We analyze the properties of the ACOT scheme for heavy quark production and make use of the MS-bar massless results at NNLO and N3LO for the structure functions F2 and FL in neutral current deep-inelastic scattering to estimate the higher order corrections. For this purpose we decouple the heavy quark mass entering the phase space from the one entering the dynamics of the short distance cross section. We show numerically that the phase space mass is generally more important. Therefore, the dominant heavy quark mass effects at higher orders can be taken into account using the massless Wilson coefficients together with an appropriate slow-rescaling prescription implementing the phase space constraints. Combining the exact ACOT scheme at NLO with these expressions should provide a good approximation to the missing full calculation in the ACOT scheme at NNLO and N3LO.

Speaker: Fred Olness (Southern Methodist University)

Proceedings 272-olness_fred.pdf

Slides olness.pdf

9:10 AM On the NNLO QCD corrections to deep-inelastic heavy-quark production

We present exact results for the heavy-quark structure functions in deep-inelastic scattering (DIS) in different kinematical regimes and to next-to-next-to-leading order (NNLO) in perturbative QCD. We combine the behavior near threshold, in the high-energy limit and at asymptotically large $Q2 \gg m2$ to derive approximate expressions at NNLO accuracy. The remaining theoretical uncertainties of this approximation are negligible except in a region of small-$x$ and low $Q2$ and we illustrate the improvement in precision predictions for heavy-quark DIS.

Speaker: Sven-Olaf Moch (DESY, Zeuthen)

Slides 3.)moch.pdf

9:30 AM The singular behavior of one-loop massive QCD amplitudes with one external soft gluon

I report on the calculation of the one-loop correction to the soft-gluon current with massive fermions. This current is process independent and controls the singular behavior of one-loop massive QCD amplitudes in the limit when one external gluon becomes soft. It therefore constitutes a necessary ingredient for the numerical evaluation of observables with massive fermions at hadron colliders to next-to-next-to-leading order.

Speaker: Isabella Bierenbaum (University Hamburg)

Slides DIS12.pdf

8:30 AM → 10:00 AM Electroweak and searches

8:30 AM The MSSM after two years of LHC running

The LHC is closing in on the Minimal Supersymmetric Standard Model. The null results from superparticle searches, and the preliminary evidence for a 124-126 GeV Higgs, severely constrain various popular minimal scenarios. In this talk I will review these constraints, and point out how the LHC results can still be accommodated within the MSSM. The resulting superparticle mass spectra may provide interesting clues about the underlying model which generates the soft SUSY breaking terms.

Speaker: Mr Felix Bruemmer (Heidelberg University)

Proceedings 179-bruemmer_felix.pdf

Slides bruemmer_dis2012.pdf

8:48 AM Searches with Jets + missing Et without leptons at CMS

We present results of searches for SUSY production at CMS in events containing hadronic jets and missing energy. Various discriminants based on the event kinematics are employed to suppress standard-model backgrounds. The results are interpreted in the context of the Constrained Minimal Supersymmetric Standard Model, and of a number of "simplified models.

Speaker: Saeid Paktinat Mehdiabadi (School of Particles and Accelerator Inst. for Res. in Fundam. S)

Proceedings 224-paktinat_saeid.pdf

Slides DIS2012_SUSY_JetMet.pdf DIS2012_SUSY_JetMet.pptx

9:06 AM Searches with Jets + missing Et with leptons at CMS

We present results of searches for SUSY production at CMS in events with lepton signatures. These include final states with single isolated leptons, Z bosons decaying to lepton pairs, non-resonant same- and opposite-sign lepton pairs, and three or more isolated leptons. The results are used to exclude previously unexplored regions of the supersymmetric parameter space assuming R-parity conservation with the lightest supersymmetric particle being either a neutralino or gravitino.

Speaker: Martin Niegel (KIT - Karlsruhe Institute of Technology (DE))

Slides DIS12_CMSLeptonicSusy_Niegel.pdf

9:24 AM Search for R-partity violating SUSY signatures with the ATLAS detector

Searches for supersymmetry at the LHC also embrace signatures from R-parity violating processes. These can be final states with resonant or non-resonant lepton flavour violation or multiple leptons. The talk presents recent results from searches for R-partity violation in events containing leptons based on data recorded in 2011 by the ATLAS detector.

Speaker: Carsten Peter Meyer (Johannes-Gutenberg-Universitaet Mainz (DE))

Proceedings 73-meyer_carsten.pdf

Slides DIS2012.pdf.pdf

9:42 AM Searches for strong R-parity conserving SUSY production at the LHC with the ATLAS detector

Searches for supersymmetric squarks and gluinos in events containing jets, missing transverse momentum with or without leptons are presented. The results are based on the full data sample (5 fb-1) recorded in 2011 at sqrt(s)=7 TeV cebtre-of-mass energy by the ATLAS experiment at the LHC.

Speaker: Federica Legger (Ludwig-Maximilians-Univ. Muenchen)

Proceedings 121-legger_federica.pdf

Slides dis2012_legger.pdf

8:30 AM → 10:00 AM Future of DIS

8:30 AM PHENIX Upgrade Plans for the Next Decade

During 12 years of operations, PHENIX has measured the gluon helicity structure of the proton, probed the proton transverse spin structure, studied effects in cold nuclear matter, discovered a strongly coupled QGP and has studied many of its basic properties. In parallel with ongoing luminosity upgrades at RHIC, PHENIX is in the process of planning and commissioning a series of upgrades in order to systematically expand its physics capabilities, allowing measurement of the sea quark helicity distributions, the low x gluon distribution in heavy nuclei and charm and bottom quark production in Heavy Ion collisions. PHENIX is also planning a larger upgrade for the next decade to answer many of the questions spurred by our discoveries during the last decade. With increased acceptance and improved electromagnetic and new hadronic calorimetry in the central region, we will advance understanding of the sQGP by studying jet energy loss. We also plan to upgrade our forward physics detector with additional calorimetry and tracking acceptance. This will allow for measurements of the Sivers effect in Drell-Yan, which can test our understanding of QCD factorization. The larger acceptance will improve our access to low x distributions in heavy nuclei, and also enable measurements of jets in the forward direction, which will allow for a more systematic approach to understanding the large transverse spin measurements seen at RHIC.

Speaker: Dr Kieran Boyle (RIKEN BNL Research Center)

Proceedings 158-boyle_kieran.pdf

Slides DIS_Boyle.pdf DIS_Boyle.pptx

8:55 AM ELIC machine design

none

Speaker: Ed Nissen (JLab)

Slides Nissen_DIStalk.pdf Nissen_DIStalk.pptx

9:20 AM Accelerator Design of High Luminosity Electron-Hadron Collider eRHIC

The accelerator design of future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC is presented. We plan adding energy recovery linacs to accelerate the electron beam to 20 (potentially 30) GeV and to collide the electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10^34 cm^-2 s^-1 can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. The important eRHIC R&D items include the high-current polarized electron source, the coherent electron cooling and the compact magnets for re-circulating passes. A natural staging scenario is based on step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs.

Speaker: Vadim Ptitsyn (B)

Proceedings 125-vadim_ptitsyn.pdf

Slides VP_erhic_accelerator.pdf VP_erhic_accelerator.pptx

8:30 AM → 10:00 AM Spin physics

8:30 AM Insights into the nucleon spin from lattice QCD

Flavour singlet contributions to the nucleon spin are elusive due to the fact that they cannot be determined directly in experiment but require extrapolations to the small x region. Direct calculations of these contributions are possible using Lattice QCD, however, they pose a significant computational challenge due to the presence of disconnected quark line diagrams. I report on recent progress in determining these sea quark contributions on the lattice.

Speaker: Sara Collins (University of Regensburg)

Proceedings 123-collins_sara.pdf

Slides talk.pdf

9:05 AM HERMES latest results on phi meson spin density matrix elements

The HERMES experiment at DESY, Hamburg collected a set of data on hard exclusive vector meson (rho,phi,omega) leptoproduction using the 27.6 GeV self-polarized lepton beam of HERA accelerator and longitudinally or transversely polarized or unpolarized gas target. The latest results on spin density matrix elements of exclusive phi meson production using the full statistics collected at HERMES, are presented. Conclusions on the helicity amplitudes, which are related to spin density matrix elements, are also presented.

Speaker: Mayya Golembiovskaya (DESY)

Proceedings 69-golembiovskaya_mayya.pdf

Slides

• Mayya.pdf
• Presentation2.pdf
• Presentation2.pptx

9:30 AM Fragmentation functions at Belle

Fragmentation functions (FFs) describe the formation of final state particles from a partonic initial state. Precise knowledge of these functions is a key ingredient in accessing quantities such as the nucleon spin structure in semi-inclusive deep inelastic scattering and proton proton collisions. However, fragmentation functions can currently not be determined from first principles Quantum Chromodynamics and have to be extracted from experimental data. The Belle experiment at KEK, Japan, provides a large data sample for high precision measurements of quantities allowing for first-time or more precise extractions of fragmentation functions. Completed and ongoing analyses for extractions of spin-independent (unpolarized FFs) as well as spin-dependent fragmentation functions (Collins and Interference FFs) at Belle will be presented.

Speaker: Mr Martin Leitgab (University of Illinois at Urbana-Champaign)

Proceedings 64-leitgab_martin.pdf

Slides leitgab_DIS2012_fragmentationfunctionsBelle_032812.pdf

10:10 AM → 10:30 AM Coffee break

10:30 AM → 12:10 PM Combined: Hadronic final states/diffraction and vector mesons

10:30 AM Dijet Production in QCD and N=4 SYM

Perturbative N=4 SYM computations for dijet production within the BFKL regime are shown to approach closely QCD predictions for suitable observables sensitive to the Möbius invariance of Regge limit. This similarity is strengthened by an appropriate choice of renormalization scale.

Speaker: José Daniel Madrigal (IFT UAM/CSIC, Madrid)

Proceedings 131-madrigal_jose_1.pdf

Slides Madrigal_Dijets_N=4.pdf

10:50 AM Next-to-leading and resummed BFKL evolution with saturation boundary

We investigate the effects of the saturation boundary on small-x evolution at the next-to-leading order accuracy and beyond. We demonstrate that the instabilities of the next-to-leading order BFKL evolution are not cured by the presence of the nonlinear saturation effects, and a resummation of the higher order corrections is therefore needed for the nonlinear evolution. The renormalization group improved resummed equation in the presence of the saturation boundary is investigated, and the corresponding saturation scale is extracted. A significant reduction of the saturation scale is found, and we observe that the onset of the saturation corrections is delayed to higher rapidities. This seems to be related to the characteristic feature of the resummed splitting function which at moderately small values of x possesses a minimum.

Speaker: David Zaslavsky (Penn State University)

Proceedings 215-zaslavsky_david.pdf

Slides dis2012presentation.pdf

11:10 AM NLO BFKL jet phenomenology with Lipatov's high energy effective action

We report on recent progress in the evaluation of next-to-leading order (NLO) corrections to forward-backward jet observables, using Lipatov's QCD high energy effective action. We calculate both real and virtual corrections to the quark induced forward jet vertex at NLO, making use of a new regularization method and a subtraction mechanism. We also present the real NLO corrections to the quark induced Mueller-Tang jet vertex. Together with the already know virtual corrections it will allow for the construction of the complete NLO Mueller-Tang jet impact factor which is the only missing element for a complete NLO BFKL description of jet events with rapidity gap.

Speaker: Dr Martin Hentschinski (IFT UAM/CSIC Madrid)

Proceedings 53-hentschinski_martin_1.pdf

Slides effectivedis12.pdf

11:30 AM Resummation of large-x and small-x double logarithms in DIS and semi-inclusive e+e- annihilation

Recently a method has been developed to extend the resummation of large-x double logarithms in inclusive DIS and semi-inclusive e^+e^- annihilation (SIA) to terms and quantities not addressed by the soft-gluon exponentiation. The N^nLL (leading log, next-to-leading log etc) resummation is based on N^nLO fixed-order results, the large-x structure of DIS and SIA in dimensional regularization and the all-order factorization of mass singularities. The same formalism can be applied to the dominant x-1 ln^{2*n-a-n_0} x terms in SIA splitting functions and coefficient functions and the (in the flavour-singlet case) subdominant x0 ln^{2*n-a-n_0} x contributions to (most of) their DIS counterparts. The talk addresses the theoretical basics of these resummations and presents the main numerical results which, despite all formal similarities, are qualitatively different for DIS and SIA.

Speaker: Andreas Vogt (University of Liverpool)

Slides av-dis12a.pdf

10:30 AM → 11:30 AM Combined: Heavy flavours/structure functions

10:30 AM Measurement of charm production in DIS with D* mesons and extraction of F2cc

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 < 0.7. The observed cross sections is extrapolated to the full pt(D*) and eta(D*) range in order to determine the open-charm contribution, F2cc(x,Q2) to the proton structure function, F2.

Speaker: Andrii Gizhko (Kiev University + DESY)

Proceedings 45-gizhko_andrii.pdf

Slides dstarzeus.pdf

10:48 AM Charm production in DIS using inclusive secondary vertices and extraction of F2cc

Charm production in deep inelastic scattering has been measured with the ZEUS detector using the full HERA II data set. The charm content in events with a jet has been extracted using the decay length significance and invariant mass of secondary vertices. Differential cross sections as a function of Q2, Bjoerken x, ET(jet) and eta(jet) were measured and compared to theoretical predictions. The open charm contribution to the proton structure function F2 was extracted from double differential cross sections.

Speaker: Vladislav Libov (DESY)

Proceedings 46-libov_vladyslav.pdf

Slides 37_DIS12_March2012.pdf

11:06 AM Measurement of D^{*\pm} Meson Production and Determination of F_2^{ccbar} at low Q2 in Deep-Inelastic Scattering at HERA

Inclusive production of D* mesons in deep-inelastic ep scattering at HERA is studied in the range 5 < Q^2 <100 GeV^2 of the photon virtuality and 0.02 < y < 0.7 of the inelasticity of the scattering process. The observed phase space for the D* meson is p_T(D*) > 1.25 GeV and |eta(D*)| < 1.8. The data sample corresponds to an integrated luminosity of 348 pb^{-1} collected with the H1 detector. Single and double differential cross sections are measured and the charm contribution F_2^{ccbar} to the proton structure function F_2 is determined. The results are compared to perturbative QCD predictions at next-to-leading order implementing different schemes for the charm mass treatment and with Monte Carlo models based on leading order matrix elements with parton showers.

Speaker: Eva Hennekemper (Uni Heidelberg)

Proceedings 191-hennekemper_eva.pdf

Slides hennekemper.pdf

10:30 AM → 12:00 PM Electroweak and searches

10:30 AM Supersymmetry beyond the MSSM after the first LHC data

We review the status of motivated beyond-MSSM scenarios in the light of the first searches at the LHC. In particular, we discuss the consequences for model building of a Higgs boson at about 125 GeV and of taking seriously the excess in the direct CP violation in the charm sector.

Speaker: Paolo Lodone (Scuola Normale Superiore of Pisa)

Slides LodoneDIS12.pdf

10:48 AM Search for supersymmetry in events involving third generation squarks and sleptons with ATLAS

Supersymmetry with large mixing between left and right scalar fermions predicts that the lightest partners of the SM fermions belong to the third generation. Moreover, naturalness arguments favour stop masses not too far from that of the top quark. The talk presents results from searches for gluino mediated sbottom and stop production, direct sbottom production, and gluino and squark mediated stau production using data recorded with the ATLAS detector in 2011.

Speaker: Carlos Chavez Barajas (CERN)

Slides CarlosChavezDIS2012.pdf

11:06 AM Searches for direct supersymmetric gaugino production with the ATLAS detector

Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the Higgs and electroweak gauge bosons, so-called gauginos, with masses not too far from those of their Standard Model counterparts. Gauginos with masses less than a few hundred GeV can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded in 2011 by the ATLAS detector. The talk presents results from searches for direct gaugino production in final states with leptons and missing transverse momentum.

Speaker: Louise Heelan (University of Texas at Arlington (US))

Slides LHeelan_ATLASDirectGauginoProduction.pdf

11:24 AM SUSY searches with Photons at CMS

We present results of searches for SUSY production at CMS in events with one or two isolated photons. The results are interpreted in terms of gauge-mediation models, with the gravitino as the lightest supersymmetric particle.

Speaker: Dongwook Jang (Carnegie-Mellon University (US))

Slides dwjang_dis_2012.pdf

11:42 AM Searches for SUSY with third-generation signatures in CMS

We present results of searches for SUSY production at CMS in events containing hadronic jets and missing energy. The tagging of heavy flavor in the jets is used both to distinguish standard-model components, and for sensitivity to those SUSY models that lead to final states rich in heavy-flavored particles.

Speaker: Alexis Kalogeropoulos (Inter-University Institute for High Energies (BE))

Proceedings 227-kalogeropoulos_alexis.pdf

Slides DIS2012.pdf

10:30 AM → 12:35 PM Future of DIS

10:30 AM ELIC Detector and IR design including current R&D

Speaker: Cynthia Keppel (Hampton University)

Slides DIS12_MEIC_DET_IR_Keppel.pdf

10:55 AM The STAR Experiment: The second decade and beyond.

The STAR experiment is one of the flagship experiments at the Relativistic Heavy-Ion Collider at Brookhaven Lab. Since starting to take data at the turn of the century, STAR’s large acceptance and measurement capabilities have proved to be vital in terms of characterising the QGP soup produced in heavy-ion collisions and heading towards a measurement of the proton spin in polarised p+p collisions. This has only been achieved through the constant upgrade and enhancement of detectors and components every year, one of many examples being the recordable DAQ rate increasing by a factor of 10^3 since the first year. Although many measurements have been performed in the last decade, much remains to be done. In this presentation I will outline the proposed measurements and corresponding detector upgrades over the next decade in p+p, p+A and A+A physics as well as STAR’s role in the transition of RHIC to an eRHIC accelerator complex.

Speaker: Dr Matthew Lamont (BNL)

Proceedings 157-lamont_matthew.pdf

Slides DIS2012_Lamont_STARFuture_ReallyFinal.pdf

11:35 AM Forward/backward detectors at an LHeC

none

Speaker: Armen Bunyatyan (DESY)

Proceedings 332-buniatyan_armen.pdf

Slides DIS12.Buniatyan.pdf

10:30 AM → 12:00 PM Spin physics

10:30 AM Transverse single spin asymmetries

Large transverse single spin asymmetries (SSAs) of cross sections with a large momentum transfer in high energy collisions were once thought impossible in QCD. With over 30 years of experimental as well as theoretical efforts, large SSAs are not only possible in QCD, but also carry extremely valuable information on the motion and structure of quarks and gluons inside a polarized hadron. In this talk, I will review the physics behind the measured SSAs and the twist-3 mechanism to generate the SSAs. I will also discuss the transition between TMD factorization approach to twist-3 collinear factorization approach to SSAs.

Speaker: Dr Jian-Wei Qiu (Brookhaven National Lab)

Proceedings 30-qiu_jianwei.pdf

Slides Qiu-dis2012.pdf

11:05 AM PHENIX Transverse Spin Physics Results

Utilizing the RHIC polarized proton collider with transverse spin the PHENIX detector carried out cross section and asymmetry measurements in inclusive pizero and eta production at mid rapidity |n| < 0.35 using the central EM calorimeters where vanishing asymmetries were found. However, significant pizero and eta asymmetries were measured in the forward rapidity 3.1 < n < 3.9 using the MPC calorimeter. An inclusive cluster analysis of the MPC data also resulted in significant asymmetries. We will discuss the results in terms of energy dependence, the Sivers or Collins contributions at low transverse momentum, and higher Twist approaches at higher momenta. Future plans such as a inclusive jet production and Drell Yan measurements will also be presented.

Speaker: Dr Yousef Makdisi (Brookhaven National Laboratory)

Slides Makdisi_DIS2012.pdf Makdisi_DIS2012.ppt

11:30 AM Single and Double Spin Asymmetry Measurements in Semi-Inclusive and Inclusive DIS on Polarized He-3

Jefferson Lab experiment E06-010 measured the target-single spin (SSA) and double spin asymmetries (DSA) in semi-inclusive deep inelastic pion electroproduction on a transversely polarized He-3 target. The measured asymmetry (A_UT) is sensitive to the nucleon transversity and Sivers distribution functions, whereas the measured A_LT asymmetry is related to the transverse momentum dependent PDF g_1T. The kinematics were chosen to be in the valence quark region with x ~ 0.16-0.35 and Q^2 ~ 1.4-2.7 GeV^2. The Collins moment, which is sensitive to transversity, the Sivers and A_LT moments, which are sensitive to the orbital motion of the quarks, were extracted using the azimuthal angular dependence of the measured asymmetries. These data, when combined with the data from other experiments on transversely polarized proton and deuteron targets, will help in extracting the nucleon transverse momentum dependent distribution functions via a global analysis. These semi-inclusive results will be presented and discussed along with the preliminary results for the inclusive single spin asymmetries.

Speaker: Vincent Sulkosky (MIT)

Proceedings 139-sulkosky_vincent.pdf

Slides DIS2012_VSulkosky_Transversity_final.pdf DIS2012_VSulkosky_Transversity_final.pptx

11:30 AM → 12:08 PM Heavy flavours

11:30 AM Quarkonium Production in ATLAS

The production of Quarkonium is an important testing ground for QCD calculations. The J/ psi and Upsilon production cross-sections are measured in proton-proton collisions at the ATLAS detector. Differential cross sections as a function of transverse momentum and pseudorapidity will be presented. The fraction of J/\psi produced in $B$-hadron decays are also measured and the differential production cross-sections of prompt and non-prompt J/ \psi determined separately. Results are compared to predictions from perturbative QCD calculations.

Speaker: Susan Cheatham (McGill University (CA))

Proceedings 84-cheatham_sue.pdf

Slides DIS2012_Quarkonium.pdf

11:48 AM Measurements of Quarkonium production at CMS

Abstract missing

Speakers: Daniele Fasanella (Universita e INFN (IT)), Daniele Fasanella (INFN)

Proceedings 238-fasanella_daniele.pdf

Slides Quarkonium_Fasanella_DIS2012.pdf

11:30 AM → 12:10 PM Structure functions

11:30 AM Quantitative constraints on the gluon distribution function in the proton from collider isolated-photon data

The impact of isolated-photon data from proton-(anti)proton collisions at RHIC, SppbarS, Tevatron and LHC energies, on the parton distribution functions of the proton is studied using a recently developed Bayesian reweighting method. The impact on the gluon density of the 35 existing isolated-gamma measurements is quantified using next-to-leading order (NLO) perturbative QCD calculations complemented with the NNPDF2.1 parton densities. The NLO predictions are found to describe well most of the datasets from 200 GeV up to 7 TeV centre-of-mass energies. The isolated-photon spectra recently measured at the LHC are precise enough to constrain the gluon distribution and lead to a moderate reduction (up to 20%) of its uncertainties around fractional momenta x~0.02. As a particular case, we show that the improved gluon density reduces the PDF uncertainty for the Higgs boson production cross section in the gluon-fusion channel by more than 20% at the LHC. We conclude that present and future isolated-photon measurements constitute an interesting addition to coming global PDF analyses.

Speaker: David d'Enterria (CERN)

11:50 AM HERAFitter

HERAFitter, a common initiative of the H1 and ZEUS collaborations, is an open source software package which provides a framework for precision QCD analyses, based on the evolution package of QCDNUM. The beta-release of the HERAFItter package contains a set of programs to fit inclusive deep inelastic scattering cross section data from HERA as well as Drell-Yan and inclusive jet processes, which are included using APPLGRID and FastNLO interfaces. HERAFitter provides an optimal platform to perform elaborate benchmarking studies of different theoretical models with rigorous treatment of experimental uncertainties. The package enables the determination of the proton parton density functions (PDFs) using precise data from LHC.

Speaker: Voica Ana Maria Radescu (Deutsches Elektronen-Synchrotron (DE))

Slides herafitterDIS.pdf

12:10 PM → 1:30 PM Lunch break

1:30 PM → 3:35 PM Combined: Diffraction and vector mesons/spin physics

1:30 PM Imaging partons using exclusive scattering processes

The spatial distribution of partons in the proton or a nucleus can be probed in suitable exclusive scattering processes. I review the theoretical foundation and the physics interest of this idea, and I report on recent performance estimates for parton imaging in the proton at an Electron-Ion collider.

Speaker: Markus Diehl (DESY)

Proceedings 98-diehl_markus.pdf

Slides dis12.pdf

1:55 PM GPD analysis of hard scattering processes : progress report

We present some recent results on the analysis of hard scattering processes in the framework of Generalized Parton Distributions. In particular we compute DVCS observables on unpolarized targets with the Kroll - Goloskokov model (suited to DVMP analysis). We also discuss NLO contributions to DVCS and TCS processes for various kinematic settings (collider and fixed target experiments).

Speaker: Hervé MOUTARDE (I)

Proceedings 154-moutarde_herve.pdf

Slides moutarde_dis_2012.pdf

2:15 PM Spin structure of the "forward" nucleon charge-exchange reaction n + p ---> p + n and the deuteron charge-exchange breakup

The structure of the nucleon charge-exchange process n + p --> p + n is investigated basing on the isotopic invariance of the nucleon-nucleon scattering. Using the operator of permutation of the spin projections of the neutron and proton, the connection between the spin matrices, describing the amplitude of the nucleon charge-exchange process at zero angle and the amplitude of neutron elastic scattering on the proton in the "backward" direction, has been considered. Due to the optical theorem, the spin-independent part of the differential cross-section of the process n + p --> p + n at zero angle for unpolarized particles is expressed through the difference of total cross-sections of unpolarized proton-proton and neutron-proton scattering. Meantime, the spin-dependent part of this cross-section is proportional to the differential cross-section of the deuteron charge-exchange breakup d + p --> (pp) + n at zero angle at the deuteron momentum {\bf k}_d = 2{\bf k}_n ( {\bf k}_n is the initial neutron momentum ). Analysis shows that, assuming the real part of the spin-independent term of the "forward" amplitude of the process n + p --> p + n to be smaller or of the same order as compared with the imaginary part, in the wide range of neutron laboratory momenta k_n > 700 MeV/c the main contribution into the differential cross-section of the process n + p --> p + n at zero angle is provided namely by the spin-dependent term .

Speaker: Dr Valery Lyuboshitz (Joint Institute for Nuclear Research, Dubna, Russia)

Proceedings 18-lyuboshitz_valery_2.pdf

Slides DIS_2012--Valery_Lyuboshitz_2.pdf

2:35 PM Overview of Deeply Virtual Compton Scattering at HERMES

Deeply Virtual Compton Scattering represents the best experimental channel through which to understand Generalised Parton Distributions. The HERMES experiment measured the most diverse set of DVCS results of any experiment; this talk discusses the most recent sets of DVCS results released by HERMES and the unique experimental conditions found at HERMES that facilitated the measurements. We also examine the various ways in which the HERMES experimental measurements are being used to constrain GPDs and how future experiments can learn from the HERMES program.

Speaker: Morgan Murray (U)

Proceedings 4-murray_morgan.pdf

Slides DIS2012.pdf

2:55 PM Vector Meson Production and DVCS at CLAS and CLAS12

Generalised Parton Distributions (GPDs) offer an insight into the three-dimensional structure of the nucleon and its internal dynamics, relating the transverse position of quarks to their longitudinal momentum. Two effective means of accessing GPDs are Deeply Virtual Compton Scattering (DVCS) and Meson Production (DVMP), in which a high energy electron scatters from a single quark in the nucleon and, respectively, a real photon or meson is produced as a result. Jefferson Laboratory (JLab), USA, is ideally suited for measuring these processes and a very active experimental programme has been underway in the recent years, making use of the lab's continuous electron beam up to 6 GeV in energy and its large angle spectrometer CLAS. In the future, a vast, new, as-yet unprobed kinematic region will become experimentally accessible when the current upgrade of the JLab accelerator to operate at a maximum energy of 12 GeV is completed in a few years. It is being complemented by the construction of a new suite of detectors, CLAS12, a number of them optimised specifically for exclusive reconstruction of DVCS and DVMP in the new kinematic region. We present a selection of recent results of DVCS and DVMP measurements using CLAS and introduce the exciting experimental programme planned for the future with CLAS12.

Speaker: Dr Daria Sokhan (in2p3)

Proceedings 355-sokhan_daria.pdf

Slides DariaSokhan_DIS2012.pdf

3:15 PM Hard Exclusive Meson Production at COMPASS and Future DVCS Measurements at COMPASS-II

New results for the transverse target spin azimuthal asymmetry $A_{UT}^{\sin(\phi-\phi_S})$ for hard exclusive $\rho^0$-meson production on a transversely polarised NH$_3$ target will be presented. The measurement was performed in 2007 and 2010 with the COMPASS detector using the 160\,GeV/$c$ muon beam of the SPS at CERN. The asymmetry is sensitive to the nucleon helicity-flip generalised parton distributions $E^q$, which are related to the orbital angular momentum of quarks in the nucleon. The DVCS program of the future COMPASS-II experiment, dedicated to investigate the nucleon structure through Generalised Parton Distributions is presented as well. The high energy muon beam from CERN SPS allows to measure these processes in a wide and up to now uncovered range in Bjorken $x$ and $Q^2$. The availability of muon beams with opposite charges and polarisations provides unique possibilities to access the GPDs.

Speaker: Heiner Wollny (CEA - Centre d'Etudes de Saclay (FR))

Proceedings 127-wollny_heiner.pdf

Slides wollny_dis2012.pdf

1:30 PM → 3:30 PM Combined: Electroweak and searches/structure functions

1:30 PM Z' production in an extended MSSM

Searching for heavy neutral gauge bosons Z', predicted in extensions of the Standard Model based on a U(1)' gauge symmetry, is among the main new physics investigations undertaken by the experiments at the Tevatron and at the Large Hadron Collider. I will discuss study Z' phenomenology at hadron colliders according to several U(1)'-based models and in the Sequential Standard Model. In particular, as far as its decay is concerned, we shall include possible Z' decays into supersymmetric particles, besides the Standard Model modes so far investigated. Results on branching ratios and cross sections will be presented, as a function of the MSSM and U(1)' parameters, which will be varied within suitable ranges. Special attention will be paid to the decay into chargino, neutralino and charged-slepton pairs and gauge the feasibility to discover supersymmetry through this channel at the LHC.

Speaker: Gennaro Corcella

Proceedings 316-corcella_gennaro.pdf

Slides corcella.pdf

1:48 PM Measurements of dibosons with the ATLAS detector and associated constraints on new physics

Diboson cross sections have been measure for all combinations of W,Z and isolated photons. The cross sections are measured in kinematic regions defined by the decay kinematics, in some cases including vetoes on additional jets. The measurements are also extrapolated to the full phase space using theoretical calculations of the acceptance, and are additionally used to place contsraints on triple-gauge boson couplings.

Speaker: Hugh Skottowe (Harvard University (US))

Proceedings 77-skottowe_hugh.pdf

Slides skottowe_dis20120328_atlasDibosons.pdf

2:06 PM Diboson Measurements with the CMS Detector

We present studies of diboson production in pp collisions at 7 TeV center-of-mass energy based on data recorded by the CMS detector at the LHC in 2010 and 2011. These include precise measurements of W and Z production in association with a photon and of WW production, WZ and ZZ productions at the LHC. The leptonic decay modes of the W and Z bosons are used. The results are interpreted in terms of constraints on anomalous triple gauge couplings.

Speaker: Santiago Folgueras (Universidad de Oviedo (ES))

Proceedings 228-folgueras_santiago.pdf

Slides Folgueras_DibosonsAtCMS.pdf

2:24 PM WZ/WW at the Tevatron (including WW/WZ+jets)

WZ/WW at the Tevatron (including WW/WZ+jets)

Speaker: Mika Vesterinen (University of Manchester)

Proceedings 280-vesterinen_mika.pdf

Slides Vesterinen_DIS_2012.pdf

2:42 PM W mass measurements from the Tevatron

The CDF collaboration has analyzed 2.2 fb-1 of Run II electron and muon data for a new precise determination of the mass of the W boson. The result is 80.387 +/- 0.019 GeV/c2, which is more precise than the combination of all preceding measurements. An update from D0 is also expected.

Speaker: Tom Riddick

Proceedings 281-riddick_thomas.pdf

Slides W_Mass_Measurements_from_the_Tevatron.pdf

3:00 PM Elastic Z0 production at HERA

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 calorimeter closest to the proton beam direction. A di-jet mass peak is observed at the Z0 mass and the number of signal events is extracted from a fit to the mass spectrum. The elastic Z0 production cross section is determined and compared to the SM prediction.

Speaker: Takuya Nobe (Tokyo Institute of Technology (JP))

Proceedings 41-nobe_takuya.pdf

Slides elasticZ0atHERA_280212_DIS.pdf

1:30 PM → 4:05 PM Future of DIS

1:30 PM The LHeC Central Detector

none

Speaker: Alessandro Polini (Universita e INFN (IT))

Proceedings 331-polini_alessandro.pdf

Slides polini-dis2012.pdf

2:10 PM LHeC Interaction Region

none

Speaker: Rogelio Tomas Garcia (CERN)

Slides SLIDES.pdf

2:40 PM An eRHIC Detector: Design Consideration and its Realization by Means of Detector R&D

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 the possibility of using the two existing, but upgraded IP detectors and a dedicated eRHIC detector. A detector has to be designed that can make use of present knowledge and experience gained from the HERA detectors, but has to be adapted such that it is able to cope with the EIC physics program. This presentation will describe the eRHIC detector design and its IR as well the presently ongoing R&D activities for making technology choices towards such a detector.

Speaker: Klaus Dehmelt (Stony Brook University USA)

Proceedings 138-dehmelt_klaus.pdf

Slides KD_DIS2012eRHICfinal.pdf KD_DIS2012eRHICfinal.pptx

3:05 PM ePHENIX for eRHIC

Addition of a high intensity polarized electron beam facility which could realize Deep Inelastic Scattering (DIS) research with one of the RHIC beams is one of the future upgrades to the Relativistic Heavy Ion Collider (RHIC) presently under consideration. To take a full advantage of such machine evolution, after more than a decade of exciting physics results, both with heavy ion and polarized proton collisions, PHENIX Collaboration has launched a detector upgrade study consistent with the above collider upgrades, going in to the eRHIC era. We discuss a staged approach of the PHENIX upgrade program and physics topics we plan to address with the e-p and e-A collisions at eRHIC.

Speaker: Alexander Bazilevsky (B)

Proceedings 105-bazilevsky_alexander.pdf

Slides Bazilevsky_DIS_28mar12.pdf Bazilevsky_DIS_28mar12.pptx

1:30 PM → 3:30 PM Hadronic final states

1:30 PM Inclusive hadron production (multiplicities and spectra) in p-p collisions in CMS

Inclusive hadron production (multiplicities and spectra) in p-p collisions in CMS

Speaker: Ferenc Sikler (Hungarian Academy of Sciences (HU))

Proceedings 182-sikler_ferenc.pdf

Slides sikler_dis2012.pdf

1:50 PM Inclusive particle production

Due to its unique pseudorapidity coverage and the possibility of providing measurements at low transverse momenta, the LHCb detector allows unique insight into particle production in the forward region at the LHC. The latest LHCb soft-QCD results, the measurements of charged particle multiplicity at 7 TeV and the measurement of the p/p, K-/K+, π-/π+, (p+p)/(π-+π+), (K-+K+)/( π-+π+ ) production ratios at 0.9 TeV and 7 TeV will be presented. These results offer an important input to the understanding of baryon transport and of the hadronisation process in a kinematical range where QCD models have large uncertainties.

Speaker: Markward Britsch (Max-Planck-Gesellschaft (DE))

Proceedings 142-britsch_markward.pdf

Slides vortrag.pdf

2:10 PM Pion and Kaon multiplicities from muon-deuteron deep inelastic scattering at COMPASS

Fragmentation functions, which turn partons into non-perturbative hadronic bound states in hard-scattering reactions, play a very important role in our understanding of the proton structure. Currently, our knowledge of fragmentation functions originates mainly from existing global QCD analyses which are mostly based on inclusive measurements in electron-positron annihilation process. While the latter mainly fixes the flavour singlet combinations of fragmentation functions, semi-inclusive deep inelastic scattering gives access to the flavour structure of FFs via hadron multiplicities. The COMPASS collaboration has recently measured pion and kaon multiplicities, in different combinations of bins in x, z and Q2, using 160 GeV/c muons off deuteron target. This measurement makes an experimental contribution for a deeper understanding on the fragmentation process.

Speaker: Ms Nour Makke (Trieste UNiversity, INFN)

Proceedings 100-makke_nour.pdf

Slides Makke_DIS2012.pdf

2:30 PM Multidimensional Hadron Attenuation

Hadron multiplicity ratios in semi-inclusive deep-inelastic scattering have been measured on neon, krypton and xenon targets relative to deuterium using the 27.6 GeV beam of HERA at the HERMES experiment. They are presented for pions (π+, π-), kaons (K+, K-), protons and anti-protons as a function of the virtual photon energy ν, its virtuality Q2, the fractional hadron energy z and the transverse hadron momentum pt with respect to the direction of the virtual photon. Dependences are presented in a two-dimensional representation, in the form of detailed binning over one variable and three slices over the other variable. These results may help to understand some aspects of the hadronization process.

Speaker: Mr Gevorg Karyan (A.I. Alikhanyan National Science Laboratory)

Proceedings 56-karyan_gevorg.pdf

Slides Hadron_Attenuation.pdf

2:50 PM Scaled Momentum Distributions for K^0_s and Lambda/anti-Lambda in DIS at HER

Scaled momentum distributions for the strange hadrons K0s and Lambda/Lambdabar were measured in deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 330 pb-1. The evolution of these distributions with the photon virtuality, Q2, was studied in the kinematic region 10 < Q2 < 40000 GeV2 and 0.001 < x < 0.75, where x is the Bjorken scaling variable. Clear scaling violations are observed. Predictions based on different approaches to fragmentation were compared to the measurements. Tuned leading-logarithm parton-shower Monte Carlo calculations interfaced to the Lund string fragmentation model describe the data reasonably well in the whole range measured. Next-to-leading-order QCD calculations based on fragmentation functions, FFs, extracted from e+e- data alone, fail to describe the measurements. The calculations based on FFs extracted from a global analysis including e+e-, ep and pp data give an improved description. The measurements presented in this paper have the potential to further constrain the FFs of quarks, anti-quarks and gluons yielding K0s and Lambda/Lambdabar strange hadrons.

Speaker: Iris Abt (Werner-Heisenberg-Institut)

Proceedings 42-abt_iris_1.pdf

Slides Scaledid.pdf Scaledid.pdf

3:10 PM On the pair correlations of neutral K, D, B and B_s mesons with close momenta produced in inclusive multiparticle processes

The phenomenological structure of inclusive cross sections of the production of two neutral K mesons in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions is investigated taking into account the strangeness conservation in strong and electromagnetic interactions. Relations describing the dependence of the correlations of two short-lived and two long-lived neutral kaons $K^0_S K^0_S$, $K^0_L K^0_L$ and the correlations of "mixed" pairs $K^0_S K^0_L$ at small relative momenta upon the space-time parameters of the generation region of $K^0$ and $\bar{K}^0$ mesons have been obtained. These relations involve the contributions of Bose-statistics and S-wave strong final-state interaction of two $K^0$ ( $\bar{K}^0$ ) mesons as well as of a $K^0$ meson with a $\bar{K}^0$ meson, and also the contribution of transitions $K^+ K^- --> K^0 \bar{K}^0$, and they depend upon the relative fractions of produced pairs $K^0 K^0$, $\bar{K}^0\bar{K}^0$ and $K^0\bar{K}^0$. It is shown that under the strangeness conservation the correlation functions of the pairs $K^0_S K^0_S$ and $K^0_L K^0_L$, produced in the same inclusive process, coincide, and the difference between the correlation functions of the pairs $K^0_S K^0_S$ and $K^0_S K^0_L$ is conditioned by the production of the pairs of non-identical neutral kaons $K^0 \bar{K}^0$. Analogous correlations for the pairs of neutral heavy mesons $D^0$, $B^0$ and $B_s^0$, generated in multiple processes with the charm (beauty) conservation, are analyzed, and differences from the case of neutral K mesons are discussed .

Speaker: Dr Valery Lyuboshitz (Joint Institute for Nuclear Research, Dubna, Russia)

Proceedings 17-lyuboshitz_valery_1.pdf

Slides DIS_2012--Valery_Lyuboshitz_1.pdf

1:30 PM → 3:38 PM Heavy flavours

1:30 PM Testing NRQCD factorization with J/psi yield and polarization at NLO

We study the polarization observables of $J/\psi$ hadroproduction at NLO in NRQCD, including the $^3\!P_J^{[8]}$ channel. Exploiting the color-octet long-distance matrix elements previously extracted through a global fit to unpolarized $J/\psi$ production data, we provide theoretical predictions in the helicity and Collins-Soper frames and compare them with data from CDF and ALICE. The notorious CDF $J/\psi$ polarization anomaly familiar from leading-order analyses persists at the quantum level, while the situation looks promising for the LHC.

Speaker: Prof. Bernd Kniehl (Univ. Hamburg)

Slides kniehl_dis12.pdf

1:48 PM Charmonium production in pp collisions with ALICE

Due to their large mass, heavy quark pairs are considered to be produced in the first instants of the collision in hard scatterings of partons which can be described perturbatively. However, the bound states of these pairs are produced via soft non-perturbative processes. The interplay between the perturbative and non-perturbative processes involved in quarkonium production makes this field a very important testing ground for QCD. At the LHC, the special setup of the ALICE experiment allows the study of charmonium production in pp collisions down to zero transverse momentum in a large rapidity range, $|y|<0.9$ and $2.5<y<4.0$. We will present results on charmonium production from pp collisions recorded by ALICE at $\sqrt{s}=$~2.76 and 7 TeV. These will include, among others, the first LHC measurements on $J/\psi$ polarization and the dependence of $J/\psi$ production on the event charged particle multiplicity. The data will be discussed using calculations from different theoretical models. We will also show results on the $J/\psi$ production in Pb--Pb collisions at $\sqrt{s_{NN}}=$~2.76 TeV in comparison with the pp collisions.

Speaker: Ionut Cristian Arsene (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

Proceedings 152-arsene_ionut.pdf

Slides IArsene_DIS2012.pdf

2:06 PM J/psi Photoproduction in ultra-peripheral Au+Au collisions measured by RHIC-PHENIX.

Title:J/psi Photoproduction in ultra-peripheral Au+Au collisions measured by RHIC-PHENIX. Ultra-peripheral collisions are heavy-ion collisions with impact parameter larger than twice the nuclear radius. Since there is no nuclear overlap, strong interactions cannot occur and ions interact through photon-ion (coherent), photon-nucleus (incoherent), and photon photon collisions. Measurement of vector meson photo production is a sensitive probe of gluon distribution in nuclei. At RHIC energy, measurement of J$/\psi$ photo production corresponds to x $\cong$ 0.015 and Q$^{2}$ =2.5 $GeV/c^2$. In the kinematic region, nuclear shadowing plays an important role and that still have large uncertainty. PHENIX has the capability of measuring J$/\psi$'s via their dielectron decays at mid-rapidity ($|y|<0.35$) and dimuon decays at forward (1.2$<|y|<$2.2) rapidity. PHENIX published J$/\psi$ photo production cross section at mid-rapidity in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV in the 2004 dataset [1] (add reference in the end). The measured cross section was found to be consistent with theoretical calculations within its statistical error. PHENIX collected higher statistics Au+Au collisions datasets in 2007 and 2010 that allow a more precise measurement over a wider rapidity range. In this talk I will present present new preliminary results for the integrated and differential cross section of UPC J$/\psi$ at central and forward rapidity.

Speaker: Mr Akihisa Takahara (CNS, University of Tokyo and JRA RIKEN)

Proceedings 114-takahara_akihisa.pdf

Slides DIS2012_v2.pptx

2:24 PM Production of HF and quarkonia at CDF

We report recent studies on heavy flavor production in 1.96 TeV proton-antiproton collisions collected by the CDF detector. These include a new measurement of the spin-alignment of Y mesons using dimuon decays in 6.7 fb^-1 of data. This measurement is the first to report the full angular distributions of dimuons as functions of Y transverse momentum in both the Collins–Soper and s–channel helicity frames. This is also the first measurement of spin alignment of Υ(3S) mesons.

Speaker: Manuel Kambeitz

Proceedings 202-kambeitz_manuel.pdf

Slides DIS2012-KAMBEITZv5.pdf

2:42 PM Quarkonium results from LHCb

Studies of quarkonia production in the forward region provide important tests of NRQCD. During 2010 and 2011 the LHCb experiment has collected a dataset corresponding to an integrated luminosity of 1 fb-1 in proton-proton collisions at sqrt(s)= 7 TeV. We present studies based on 40 to 1000 fb-1 of data, including the production of the J/psi, psi(2S), Chi_c charmonium together with Upsilon and Chi_b bottomonium states. We also report measurements of double charm production, performed for the first time at a hadron collider. Absolute and relative branching ratios are presented and compared to the most recent theoretical predictions when available. In addition, we will discuss results for the exotic states the X(3872), Y(4140) and Z+(4430), and give prospects for these measurements.

Speaker: Giovanni Sabatino (Universita degli Studi di Roma Tor Vergata (IT))

Proceedings 144-sabatino_giovanni.pdf

Slides Sabatino_dis2012.pdf

3:00 PM Charmonium results at Belle

We present recent results on charmonium and charmonium-like states studied by the Belle experiment at the KEK-B e+e- collider. After years of interesting discoveries in the field of hadron spectroscopy, Belle continues the research by measuring new final states produced in various processes accessible at the B-Factories. Main motivation is to complete the spectrum of charmonia predicted by QCD and to investigate the nature of so called X,Y,Z states.

Speaker: Jolanta Brodzicka (INP Krakow)

Slides brodzicka_dis2012_v2.pdf brodzicka_dis2012_v2.ppt

3:18 PM Charmonium and charmonium-like results from BABAR

Charmonium and charmonium-like states are a unique system for studying QCD and possibly exotic bound states. We present new results on such states, which are created in two-photon fusion or in electron-positron collisions and decaying into a variety of final states, including psi pi pi, eta_c pi pi, and J/psi omega.

Speaker: Elisa Fioravanti (INFN Ferrara)

Proceedings 195-fioravanti_elisa.pdf

Slides Talk_DIS_Fioravanti_v6.pdf

3:40 PM → 4:00 PM Coffee break

4:00 PM → 5:30 PM Combined: Electroweak and searches/structure functions

4:00 PM W/Z/DY + jet as a test of the NLO BFKL kernel

We study W/Z/DY + jet events where the W/Z/DY boson is produced in the forward direction of one of the colliding protons and a jet is produced in the forward direction of the second proton. The resulting large rapidity difference between the final states then opens up the phase space for BFKL evolution which we would like to study in more detail. As a by-product of our study, we also provide an analytic expression for the high energy re-summed exclusive partonic W/Z + n jet cross-section in moment space. To construct the BFKL re-summed cross-section we determine an analytic expression for the exclusive W/Z/DY impact factor in (gamma, n) space which is combined with BFKL Green's function and jet impact factor. In particular, both impact factors are determined for non-zero conformal spin and allow therefore for the study of angular correlations. First numerical results for a number of observables which allow to isolate and test BFKL evolution are presented.

Speaker: Martin Hentschinski (Autonoma University Madrid/CSIC)

Proceedings 115-hentschinski_martin_2.pdf

Slides Zdis12.pdf

4:18 PM Measurements of W/Z production with the ATLAS detector

W and Z boson production have been measured in the electron, muon and tau decay channels. Total and differential cross sections, defined in terms of the decay lepton kinematics, have been measured as a function of rapidity and transverse momentum. Ratios of the cross sections demonstrate sensitivity to lepton universality, and the kinematic distributions constrain parton densities and QCD calculations including resummations of soft gluon radiation, and the matching of NLO matrix elements or high multiplicity tree-level matrix elements to parton shower approximations. The polarisation of W bosons is also measured, as, for the first time, is the polarisation of the tau lepton in W-->tau nu decays.

Speaker: Jean-Baptiste Sauvan (Universite de Paris-Sud 11 (FR))

Proceedings 76-sauvan_jean-baptiste.pdf

Slides sauvan_ATLAS.WZ.measurements_DIS2012.pdf

4:36 PM Measurement of W and Z production in the forward region with LHCb

We report on measurements of W and Z 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 fb-1. W and Z bosons are reconstructed in leptonic decay channels, and their cross-sections determined using data-driven techniques. Results are presented inclusively (within the fiducial region considered), and differentially as a function of boson rapidity (Z) and lepton pseudorapidity (W). The ratio of W to Z production, W+/W- production and the W charge asymmetry (for three lepton PT thresholds) is also given. All results are compared to NNLO predictions.

Speaker: Mr Stephen Farry (University College Dublin (IE))

Proceedings 147-farry_stephen.pdf

Slides DIS2012.pdf

4:54 PM Production of Z and W in association with heavy quarks at CMS

The mechanism of production of heavy-flavoured mesons, containing b or c quarks, in association with vector bosons, W or Z, in the Standard Model is only partially understood. The study of events with one or two well-identified and isolated leptons accompanied by b-jets or secondary vertices is therefore crucial to refine the theoretical calculations in perturbative QCD, as well as validate associated Monte Carlo techniques. The deep understanding of these processes is furthermore required by Higgs and BSM analyses with similar final states. Using the LHC proton-proton collision data collected in 2010 and 2011 at a centre of mass energy of 7 TeV by the CMS detector, preliminary measurements of the Z+b(b) cross sections and angular correlations are presented. Finally, the study of the W+c production rate with respect to the W charge and W+light jets rates allows to probe the strange quark content of the proton. These results are also presented.

Speaker: Marco Musich (INFN Torino (IT))

Slides mm_DIS_2012_VHF.pdf

5:12 PM Drell-Yan production in the forward region with LHCb

We report on Drell-Yan production using data collected at the LHCb experiment with a centre of mass energy of $\sqrt{s}=7$~TeV in 2010. Drell-Yan events are selected with invariant di-muon masses $M_{\mu\mu}>10$~GeV/$c^2$. These measurements are sensitive to Bjorken-$x$ values as low as $1\times 10^{-5}$ and will provide important input to the knowledge of the parton density functions. The event selection and the signal extraction is described. The cross section is measured differentially as a function of the invariant mass of the two muons.

Speaker: Jonathan Anderson (Universitaet Zuerich (CH))

Proceedings 145-anderson_jonathan.pdf

Slides LHCbDrellYan_DIS12_Anderson.pdf

4:00 PM → 5:30 PM Diffraction and vector mesons

4:00 PM Measurement of the t dependence in exclusive photoproduction of Upsilon (1S) mesons at HERA

The exclusive photoproduction reaction gamma p -> Upsilon(1S) p has been studied with the ZEUS detector in ep collisions at HERA using an integrated luminosity of 468pb-1. The measurement covers the kinematic range 60 < W < 220 GeV and Q2 < 1 GeV2, where W is the photon--proton centre-of-mass energy and Q2 is the photon virtuality. The exponential slope, b, of the t dependence of the cross section, where t is the squared four-momentum transfer at the proton vertex, has been measured, yielding b=4.3 +2.0-1.3 (stat.) +0.5-0.6 (syst.) GeV2. This constitutes the first measurement of the t dependence of the gamma p -> Upsilon(1S) p cross section.

Speaker: Jacek Ciborowski (University of Warsaw)

Proceedings 37-ciborowski_jacek.pdf

Slides Upsilon_2012.pdf

4:20 PM Exclusive Electroproduction of two Pions at HERA

The exclusive electroproduction of two pions in the mass range 0.4 < M(pipi) < 2.5 GeV has been studied with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. The analysis was carried out in the kinematic range of 2 < Q2 < 80 GeV2, 32 < W <180 GeV and |t|<0.6 GeV, where Q2 is the photon virtuality, W is the photon-proton centre-of-mass energy and t is the squared four-momentum transfer at the proton vertex. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, |F(M(pipi)|, assuming that the studied mass range includes the contributions of the rho, rho' and rho'' vector-meson states. The masses and widths of the resonances were obtained and the Q2 dependence of the cross-section ratios sigma(rho'->pipi)\sigma(rho) and sigma(rho''->pipi)/sigma(rho) was extracted. The pion form factor obtained in the present analysis is compared to that obtained in e+e- -> pipi.

Speaker: Dr Justyna Tomaszewska (DESY)

Proceedings 38-tomaszewska_justyna.pdf

Slides dis2012v2.pdf

4:40 PM A holographic light-cone wavefunction for the rho wavefunction

We obtain a very good description of the current HERA data on diffractive rho electroproduction using a holographic light-cone wavefunction for the rho meson. This holographic wavefunction is obtained using the Brodsky and de Teramond correspondance between hadronic modes in AdS space and light-cone wavefunctions in physical spacetime. We also show the corresponding holographic Distribution Amplitude is consistent with Sum Rules and lattice predictions.

Speaker: Prof. Ruben Sandapen (University of Moncton (Canada))

Proceedings 265-sandapen_ruben.pdf

Slides DIS_2012.pdf

5:00 PM New determination of the nonperturbative form factor in QCD transverse-momentum resummation for vector boson production

In the conventional b_* model for the Collins–Soper–Sterman resummation, the resummed form factor is accompanied by the nonperturbative gaussian form factor, and it is known that the nonperturbative parameter associated with the latter exhibits the strong dependence on the logarithm of the vector boson invariant mass. On the other hand, an another approach to treat the impact parameter (b space) transform in the resummation formalism has been developed as the ``minimal prescription (MP)'' based on an analytic continuation procedure. By contrast to the b_* approach, the MP has advantages that it leaves unchanged the perturbative expansion to any (and arbitrarily-high) fixed order in \alpha_s and it does not require any infrared cut-off to avoid the Landau pole in the b-space integration. In the framework of the MP, however, the behavior of the corresponding nonperturbative form factor as a function of the vector boson invariant mass has been unknown. In this work, we present a first systematic study of the nonperturbative form factor associated with the resummed form factor in the MP. The matching of the b-space resummation formulas between the MP and the b_* model indicates that the nonperturbative form factor in the MP has the milder dependence on the vector boson invariant mass than that in the b_* model . To clarify this point quantitatively, we perform a global fit of the nonperturbative form factor in the MP resummation at the next-to-leading logarithmic accuracy, with the Z boson production data at the Tevatron and the low energy Drell-Yan data. We obtain good description of the transverse momentum distribution of vector bosons using a gaussian form of the nonperturbative form factor and find the weak dependence of the corresponding nonperturbative parameter on the vector boson invariant mass, which in turn allows an interpretation as arising from the intrinsic transverse momentum of partons inside the proton.

Speaker: Prof. Kazuhiro Tanaka (Juntendo University)

Proceedings 136-tanaka_kazuhiro.pdf

Slides dis12_tanaka.pdf

4:00 PM → 5:30 PM Future of DIS

4:00 PM Higgs CP properties and the LHeC

none

Speaker: Rohini Godbole (Centre for Theoretical Studies (CTS))

Slides rohini.pdf

4:20 PM Radiative corrections in ep and eA

none

Speaker: Hubert Spiesberger

Slides HSpiesberger-RC.pdf

4:45 PM Medium-induced soft gluon radiation in the quark scattering process without color transfer in t-channel

We study coherence effects on the medium-induced soft gluon radiation off an ''asymptotic quark " traversing a hot and dense QCD medium. The transverse momentum spectrum of the emitted gluon is computed at first order in opacity expansion. The interference effects between the initial and final state radiation modify the soft gluon radiation when a finite angle between the initial and final quarks is considered. The spectrum presents a soft divergence. We comment on possible implications on observables in heavy ion collisions which are sensitive to the initial state radiation.

Speaker: Hao Ma

Proceedings 0-ma_hao.pdf

Slides DIS2012_HaoMa.pdf

4:00 PM → 5:30 PM Hadronic final states

4:00 PM Studies of jet shapes and substructure with ATLAS

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 - including the jet mass - and jet substructure have the potential to identify jets coming from massive, boosted particles decaying hadronically. Techniques have also been developed for reducing the sensitivity of jet physics to soft QCD and to multiple proton-proton collisions. A selection of such variables is also measured and compared to a range QCD calculations and phenomenological models.

Speaker: Adam Robert Davison (University College London (UK))

Proceedings 80-davison_adam.pdf

Slides AdamDavisonDIS2012.pdf AdamDavisonDIS2012.pptx

4:20 PM QCD resummation for jet-mass distributions

We study the jet-mass distribution for jets produced in hadron-hadron collision in QCD. In order to obtain reliable phenomenological results we resum to all-order in perturbation theory those contributions coming from collinear and soft gluons. Beyond the leading-logarithmic accuracy the resummation is made more complicated by the presence of non-global logarithms and logarithms related to the choice of the jet-algorithm. We apply our calculation to the interesting case of the jet-mass in Z+jet events, which is of great phenomenological interest for boosted Higgs.

Speaker: Simone Marzani (IPPP Durham)

Slides marzaniDIS2012jetmass.pdf

4:40 PM Jet Substructure at Hadron Colliders

Jet Substructure at Hadron Colliders

Speaker: Zhao Li (Michigan State University)

Slides DIS2012_talk.pdf

5:00 PM Boosted hadronically decaying tops in new physics searches

Top momentum reconstruction often plays an important role for new physics signal reconstruction at the LHC. In principle for a hadronically decaying top, it is possible to reconstruct its momentum fully but one suffers from large QCD and combinatorial backgrounds. Starting from geometrically large sizes of jets and looking into their substructure, we can efficiently reduce these background. We develop HEPTopTagger by adopting a combination of the Cambridge/Aachen algorithm and the mass drop criterion. As application for physics cases, we illustrate the scalar top reconstruction and the top forward-backward asymmetry.

Speaker: 道久 竹内 (Heidelberg)

Proceedings 270-takeuchi_michihisa.pdf

Slides DIS2012.pdf

4:00 PM → 5:30 PM Heavy flavours

4:00 PM Bottomonium(-like) states at Belle

The Belle collaboration recently reported the discovery of the p-wave Bottomonium singlets, hb(1P) and hb(2P), the surprising observation of resonant substructure in Y(5S) --> pi+pi-Y(nS), hb(mP) (n=1-3, m=1,2), and the first observation of the radiative transition hb(1P) --> gamma etab(1S) in 121.4 1/fb of data collected near the Upsilon(5S) resonance at the KEKB asymmetric-energy e^+e^- collider. We report further studies performed at this energy.

Speaker: Umberto Tamponi (Torino)

Proceedings 66-tamponi_umberto.pdf

Slides Tamponi_DIS2012.pdf

4:18 PM Confirmation of a new narrow mass state decaying into Upsilon(1S)gamma

Using the 1.3 fb$^{-1}$ sample of D0 RunII data taken between 2002 and 2006, we observe a new state decaying into $\Upsilon(1S) + \gamma$, where the $\Upsilon(1S)$ is detected by its decay into an oppositely charged muon pair, and the photon is reconstructed by its conversion into an electron-positron pair. The significance of this structure is six standard deviations and its mass is consistent with that of the state recently discovered by the ATLAS Collaboration.

Speakers: Claus Buszello (Uppsala University (SE)), Claus Buszello (Department of Physics and Astronomy-University of Uppsala), Claus Buszello (Uppsala University)

Slides DIS2012_buszello.pdf

4:36 PM Bc + b baryons studies at LHCb

During the year 2011, the LHCb experiment has accumulated 1 fb-1 of data in proton-proton collisions data at 7 TeV, collecting a sample rich in both Bc mesons and b baryons. Studies of these states provide a wealth of new measurements as well as probes of QCD theory predictions. We will present studies of Bc production together with precision measurements of both the mass and lifetime, in Bc->J/psi pi, J/psi mu nu and studies of the Bc-> J/psi 3pi mode. Measurements of the properties of \Xi_b and Omega_b baryons including the mass and studies of excited B hadron states will also be presented.

Speaker: Dr Zhenwei Yang (Tsinghua University (CN))

Slides DIS2012_Bc_and_b_baryons_studies_at_LHCb_20120328_yangzw_v3.pdf

4:54 PM Properties and decays of b hadrons at D0

Merged abstract: "Analysis of the decay $B_s^0 \rightarrow J/\psi K^+ K^-$ $M(K^+K^-)>1.35$~GeV" "Measurement of the $\Lambda_b$ lifetime in the $\Lambda_b \to J/\psi \Lambda$ exclusive decay channel using the full D0 dataset"

Speaker: Enrique Camacho Perez (Centro Invest. Estudios Avanz. IPN (MX))

Proceedings 311-camacho_enrique.pdf

Slides ecamacho_DIS2012.pdf

5:12 PM Baryonic B decay results from BABAR

Decays of B mesons into final states containing baryons are much less understood than decays into mesons, and are useful for shedding light on baryon-production mechanisms and intermediate states. We report the results of recent and new studies of such decays, including B- -->Sigma_c++ pbar pi- pi-, B0bar -->Lambda_c+ pbar p pbar, and B --> D(*) p pbar (npi). Both the total decay rates and the resonant structure are reported.

Speaker: Marcus Ebert (SLAC)

Proceedings 196-ebert_marcus.pdf

Slides Baryonic_Babar_ebert.pdf

4:00 PM → 5:30 PM Spin physics

4:00 PM Overview on Orbital Angular Momentum

In this talk, we will summarize recent developments on the orbital angular momentum of partons in nucleon, from various observables in high energy processes, including generalized parton distributions, transverse momentum dependent parton distributions, etc.

Speaker: Dr Feng Yuan (Lawrence Berkeley National Laboratory)

Proceedings 235-yuan_feng_1.pdf

Slides OAM12-Yuan.pdf OAM12-Yuan.ppt

4:30 PM Constraining quark angular momentum with the Sivers function

The determination of quark angular momentum requires the knowledge of the generalized parton distribution E in the forward limit. We assume a connection between this function and the Sivers transverse-momentum distribution, based on model calculations and theoretical considerations. Using this assumption, we show that it is possible to fit at the same time nucleon magnetic moments and semi-inclusive single-spin asymmetries. This imposes additional constraints on the Sivers function and opens a plausible way to quantifying quark angular momentum.

Speaker: Alessandro Bacchetta (University of Pavia)

Proceedings 50-bacchetta_alessandro.pdf

Slides bacchetta_DIS2012_Bonn.pdf

4:50 PM Phenomenology of Sivers Effect with TMD Evolution

Following the TMD evolution scheme recently proposed for the Sivers distribution function, we propose a simple strategy to take into account this TMD Q^2 dependence in our phenomenological extraction of the Sivers function from SIDIS data. New results are presented and possible future applications are discussed.

Speaker: Mariaelena Boglione (University of Turin)

Proceedings 256-boglione_mariaelena.pdf

Slides Boglione-DIS2012.pdf

5:10 PM Transverse Single Spin Asymmetry in ep^\up -> e+J/\psi +X$

We discuss the possibility of using electroproduction of $J/\psi $ as a probe of gluon Sivers function by measuring single spin asymmetry in experiments with transversely polarized protons and electron beams. We estimate SSA for JLab, HERMES, COMPASS and eRHIC energies using color evaporation model of charmonium production and find asymmetry up to 25 $\%$ for certain choices of model parameters which have been used earlier for estimating SSA in SIDIS and Drell Yan process.

Speaker: Dr Asmita Mukherjee (IIT Bombay)

Proceedings 49-mukherjee_asmita.pdf

Slides asmita_12.pdf

5:30 PM → 7:00 PM Departure for Satzvey Castle (bus transfer)

7:00 PM → 11:00 PM Medieval banquet

Thu, March 29

9:00 AM → 10:30 AM Combined: Electroweak and searches/heavy flavours

9:00 AM Top quark pair production beyond NLO

I present recent calculations of observables in top quark pair production at hadron colliders, including the total cross section, the invariant mass distribution, the transverse momentum and rapidity distributions, and the forward-backward asymmetry. The calculations are based on the resummation of threshold logarithms at NNLL accuracy beyond NLO.

Speaker: Li Lin Yang

Proceedings 185-yang_lilin.pdf

Slides DIS12.pdf

9:18 AM Measurements of single top quark production at ATLAS

We present the result of a measurement of single top-quark production in the t-channel at 7 TeV proton-proton collisions with the ATLAS detector at the Large Hadron Collider. A lower limit on the CKM matrix element |Vtb| is extracted from this measurement. The single-top quark production in the Wt- and s-channels is also explored.

Speakers: William Bell (Unknown), William Hamish Bell (Universite de Geneve (CH))

Proceedings 90-bell_william.pdf

Slides single-top-DIS-20120329.pdf

9:36 AM