# DIS 2014 - XXII. International Workshop on Deep-Inelastic Scattering and Related Subjects

Europe/Warsaw
Warsaw

#### Warsaw

Old Library building at the main campus of the University of Warsaw, 26/28 Krakowskie Przedmiescie str.
• Monday, 28 April
• 08:30 12:50
Plenary: Monday Morning Auditorium (BUW)

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Conveners: Barbara Pasquini (University of Pavia), Joachim Mnich (Deutsches Elektronen-Synchrotron (DE))
• 08:30
Conference opening 30m Auditorium

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• 09:00
Exploring the structure of the proton 30m Auditorium

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Speaker: Jerome Friedman (MIT)
• 09:40
Heavy flavours 30m Auditorium

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Speaker: Andre Mischke (Utrecht University (NL))
• 10:20
Forward and low-x physics 30m Auditorium

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Speaker: Pierre Van Mechelen (University of Antwerp (BE))
• 11:00
Coffee break 30m Auditorium (BUW)

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• 11:30
Precision QCD in the LHC era 30m Auditorium

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Speaker: Daniel de Florian (Universidad de Buenos Aires)
• 12:10
Hot strong matter 30m Auditorium

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Speaker: Katarzyna Grebieszkow (Warsaw University of Technology (PL))
• 12:50 14:30
Lunch break 1h 40m
• 14:30 19:00
Plenary: Monday afternoon Auditorium (BUW)

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Conveners: Amanda Cooper-Sarkar, Jechiel Lichtenstadt (High Energy Physics Department)
• 14:30
Beyond the Standard Model 30m
Speaker: Prof. Tim M.P. Tait (University of California, Irvine)
• 15:10
Higgs and EW physics 30m
Speaker: Yves Sirois (Ecole Polytechnique (FR))
• 15:50
Event generators 30m
Speaker: Leif Lönnblad (Lund University (SE))
• 16:30
Coffee break 30m
• 17:00
Structure functions and parton distributions 30m
Speaker: katarzyna wichmann (DESY)
• 17:40
30 years of spin physics in 30 minutes: past, present and future 30m
Speaker: Jianwei Qiu (Brookhaven National Lab)
• 18:20
Strategy for DIS 30m
Speaker: Rolf Ent (Jefferson Lab)
• 19:30 21:30
Social programme: Conference Reception
• Tuesday, 29 April
• 08:30 12:40
WG1: Structure Functions and Parton Densities Auditorium (BUW)

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Conveners: Karol Kovarik, Richard David Ball (Edinburgh University), Vladimir Chekelian (MPI fuer Physik)
• 08:30
Deep inelastic cross section measurements at large y with the ZEUS detector at HERA 23m
The reduced cross sections for $e^{+}p$ deep inelastic scattering have been measured with the ZEUS detector at HERA at three different centre-of-mass energies, $318$, $251$ and $225$ GeV. The cross sections, measured double differentially in Bjorken $x$ and the virtuality, $Q^2$, were obtained in the region $0.13\ \leq\ y\ \leq\ 0.75$ and $5\ \leq\ Q^2\ \leq\ 110$ GeV$^2$, where $y$ denotes the inelasticity. The proton structure functions $F_2$ and $F_L$ were extracted from the measured cross sections.
Speaker: Julia Grebenyuk (DESY)
• 08:53
Measurement of Inclusive ep Cross Sections at High Q2 at sqrt(s) = 225 and 252 GeV and of the Longitudinal Proton Structure Function FL at HERA 23m
Inclusive ep double differential cross sections for neutral current deep inelastic scattering are measured with the H1 detector at HERA. The data were taken with a lepton beam energy of 27.6 GeV and two proton beam energies of Ep = 460 and 575 GeV corresponding to centre-of-mass energies of 225 and 252 GeV, respectively. The measurements cover the region of 6.5x10^-4 ≤x ≤0.65 for 35≤Q^2≤800 GeV^2 up to y = 0.85. The measurements are used together with previously published H1 data at Ep = 920 GeV and lower Q^2 data at Ep = 460, 575 and 920 GeV to extract the longitudinal proton structure function FL in the region 1.5≤Q^2≤800 GeV^2.
Speaker: Stanislav Shushkevich (Deutsches Elektronen-Synchrotron (DE))
• 09:16
Measurement of neutral current e±p cross sections at high Bjorken x with the ZEUS detector 24m
The neutral current $e^\pm p$ cross section has been measured up to values of Bjorken $x\cong 1$ with the ZEUS detector at HERA using an integrated luminosity of 187 ${\rm pb}^{-1}$ of $e^-p$ and 142 ${\rm pb}^{-1}$ of $e^+p$ collisions at $\surd s = 318$ GeV. Differential cross sections in $x$ and $Q^2$, the exchanged boson virtuality, are presented for $Q^2 \geq 725$ GeV$^2$. An improved reconstruction method and greatly increased amount of data allows a finer binning in the high-$x$ region of the neutral current cross section and leads to a measurement with much improved precision compared to a similar earlier analysis. The measurements are compared to Standard Model expectations based on a variety of recent parton distribution functions.
Speaker: Aharon Levy (Tel Aviv University (IL))
• 09:40
Combination of Inclusive ep Cross-Section Measurements at HERA 25m
A combination is presented of all inclusive deep inelastic cross sections measured by the H1 and ZEUS collaborations in neutral and charged current unpolarised $e^{\pm}p$ scattering at HERA. The data were taken between 1994 and 2007. They span six orders of magnitude in negative four-momentum-transfer squared, $Q^2$, and in Bjorken $x$. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy.
Speaker: Oleksii Turkot (DESY)
• 10:05
HERAPDF2.0 fits including all HERAI+II inclusive data sets 25m
New combined H1 and ZEUS data on neutral and charged current inclusive cross sections at HERA from all running periods 1994-2007, are used as the sole input to NLO and NNLO QCD analyses to determine new sets of parton distributions, HERAPDF2.0, with small experimental uncertainties and an estimate of model and parametrisation uncertainties. Charm and jet production data are also included in the fit to improve, in particular, the determination of the gluon density and the strong coupling, $\alpha_s$.
Speaker: Voica Ana Maria Radescu (Deutsches Elektronen-Synchrotron (DE))
• 10:30
Coffee break 30m
• 11:00
Updates of PDFs in the MSTW framework 25m
I present an update of the PDFs obtaining using the same overall framework as MSTW. In particular I concentrate on the effect of new data sets, particularly from the LHC, but compare the changes in the PDFs resulting from this source to changes due to some differences in theoretical procedure.
Speaker: Prof. Robert Samuel Thorne (University College London (UK))
• 11:25
CT10 NNLO Global Analysis update and QED effects in PDFs 25m
An update on activities of the CTEQ-TEA global analysis project will be given. This includes discussion of the latest NNLO CT10 parton distribution functions and their implications for predictions at the LHC. We also present a study of QED effects, including photon PDFs, in the CT10 analysis, and show how the ZEUS DIS plus observed photon data can constraint the initial photon PDF.
Speaker: Carl Schmidt (Michigan State University)
• 11:50
The NNPDF3.0 parton set for the next LHC run 25m
In this talk preliminary results on the NNPDF3.0 PDF set are presented. The novel NNPDF analysis, based on an improved fitting methodology and statistically validated by closure tests, includes the most recent data from HERA and a wide set of recent LHC data. Statistical features and tests will be presented, along with the impact of the new data on PDFs. Some of the implications for the upcoming high energy LHC run will be discussed.
Speaker: Dr Maria Ubiali (RWTH Aachen University)
• 12:15
Disentangling quark distributions with the collider and fixed-target and data in the ABM PDF fit 25m
We consider impact of the recent data obtained by the LHC, Tevatron, and fixed-target experiments on the quark distributions in the nucleon with a particular focus on disentangling of different quark species. Improved determination of the poorly known strange sea distribution is obtained and the standard candle benchmarks for the Drell-Yan process at the LHC are updated.
Speaker: Sergey Alekhin (DESY-Zeuthen)
• 08:30 12:30
WG3: Electroweak Physics and Beyond the Standard Model C (BUW)

### C

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Conveners: Anna Kaczmarska (Polish Academy of Sciences (PL)), Krzysztof Turzynski (University of Warsaw), Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR)), Milada Muhlleitner (KIT - Karlsruhe Institute of Technology (DE))
• 08:30
Electroweak Corrections to Vector Boson Pair Production 20m
Vector-boson pair production plays an important role for present and future LHC experiments. Such processes allow for a solid validation of the weak sector of the SM and, moreover, provide the opportunity to search for effects of anomalous couplings predicted by various New-Physics models. To improve on the corresponding theory predictions, we present the computation of the NLO electroweak corrections to vector-boson pair production at hadron colliders. Consistently including all mass effects, our predictions are valid in all kinematic regions accessible at the LHC. The corresponding corrections are moderate at low energies, but reach several tens of percent going to higher transverse momenta or invariant masses, respectively, leading to significant distortions of transverse-momentum and rapidity distributions. To allow for a realistic event definition we include leptonic decays of the vector bosons, where spin correlations are properly taken care of. We also propose a simple and straight-forward Monte Carlo implementation of our results within the HERWIG++ setup which could be applied to further processes in the future.
Speaker: Tobias Kasprzik (KIT, Karlsruhe)
• 08:50
Diboson Higgs and EWK measurements and triple gauge couplings with ATLAS and CMS 30m
We present studies of diboson production in pp collisions at 7 and 8 TeV center-of-mass energy based on data recorded by the CMS detector at the LHC in 2011 and 2012. These include Higgs measurements in ZZ and WW decay modes, 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. Semi-leptonic decay modes of WW+WZ final state are also shown. The results are interpreted in terms of constraints on anomalous triple gauge couplings.
Speaker: Eftychia-Sofia Protopapadaki (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 09:20
Measurements of the 7 and 8 TeV cross sections for Z->4l in pp collisions 30m
A measurement of the cross section for 4 lepton production near the Z resonance is presented for sqrt(s) = 7 and 8 TeV pp collisions recorded with the ATLAS experiment. The measurement is interpreted as a determination of the branching fraction for the Z boson decaying into 4 leptons and is foundconsistent with the expectation from the Standard Model. This result provides an important benchmark for the H->4l process.
Speaker: Bing Zhou (University of Michigan (US))
• 09:50
Measurements of photon and diphoton production processes at CMS 30m
We present study of Higgs production in 2 photon decay mode, as well as differential cross-section measurements of inclusive photon production, photon+jet production, and diphoton production in pp collisions based on data recorded by the CMS detector at the LHC.
Speaker: Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR))
• 10:20
Coffee break 30m
• 10:50
Multi-boson Production in Weak Boson Fusion 20m
The production of electro-weak bosons via weak boson fusion is an important process at the LHC, as it allows testing the Standard Model (SM) in various ways. For example, if at least two bosons are produced, Feynman graphs with quartic gauge couplings appear. Therefore, this process class can be used to constrain or discover contributions from anomalous quartic gauge couplings. Also, at large invariant masses of the bosonic system, contributions from intermediate Higgs bosons are necessary to ensure the unitarization of the cross section. Deviations will occur if this unitarization is not complete, because the coupling of the Higgs to gauge bosons deviates from the SM value, or there are further Higgs bosons at higher masses. To facilitate this task, precise theoretical predictions are necessary. In this talk, I will summarize the current theoretical status of higher-order corrections and matching fixed-order calculations with parton shower. Examples will be given how this process class can be used to perform the SM tests mentioned above.
Speaker: Michael Rauch (Univ. Karlsruhe, KIT)
• 11:10
Triboson measurements, VV scattering and quartic gauge couplings with ATLAS and CMS 30m
We present measurements of triboson production and VV scattering in pp collisions at 8 TeV center-of-mass energy based on data recorded by the CMS detector at the LHC in 2012. The results are interpreted in terms of constraints on anomalous quartic gauge couplings. estigated. In addition we present studies of exclusive and quasi-exclusive gammagamma->W+W- production p-p collisions at the LHC using the CMS detector, and new limits on anomalous quartic couplings.
Speaker: Riccardo Bellan (Universita e INFN (IT))
• 11:40
Production of $W^+ W^-$ pairs via subleading processes at the LHC 20m
The standard NLO calculations underpredict the measured rates of $W^+ W^-$ production compared to recent ATLAS and CMS experimental data. We discuss new subleading processes for inclusive production of $W^+ W^-$ pairs. We focus on photon-photon induced processes. We include elastic-elastic, elastic-inelastic, inelastic-elastic and inelastic-inelastic contributions. The inelastic photon distributions in the proton are calculated in two different ways: naive approach used already in the literature and using photon distributions by solving special evolution equation with photon being a parton in the proton. The results strongly depend on the approach used. We calculate also contributions with resolved photons. %The diffractive components have similar characteristics as %the photon-photon elastic-inelastic and inelastic-elastic mechanisms. The subleading contributions are compared with the well known $q \bar q$ and $g g$ as well as with double-parton scattering contributions. Predictions for the total cross section and differential distributions in $W$- boson rapidity and transverse momentum as well as $WW$ invariant mass are presented. The $\gamma \gamma$ components constitute only about 1-2 \% of the inclusive $W^+ W^-$ cross section but about 10 \% at large $W^{\pm}$ transverse momenta. We calculate also cross section for single-diffractive production of $W^+ W^-$ pairs including pomeron and subleading reggeon exchanges in the Ingelman-Schlein model. The H1 diffractive parton distributions are used in the calculations. The results are compared to the results of elastic-inelastic (inelastic-elastic) $\gamma \gamma$ processes. M. Luszczak, A. Szczurek, arXiv:hep-ph/1309.7201
Speaker: Marta Luszczak (University of Rzeszow)
• 12:00
Measurement of the electroweak production cross section of dijets associated with vector bosons. 30m
Measurement of production of vector bosons associated with two forward jets is reported based on 20 fb-1 of data at sqrt(s) = 8 TeV recorded by the ATLAS experiment. The measurement is performed in various fiducial volumes, sensitive to QCD and Electroweak production mechanisms. The electroweak component for single Z boson production is extracted by a ﬁt to the dijet invariant mass distribution in a ﬁducial region chosen to enhance the electroweak contribution over the dominant background in which the jets are produced via the strong interaction. The measured electroweak cross sections are in good agreement with the Standard Model expectations.
Speaker: Julia Fischer (Bergische Universitaet Wuppertal (DE))
• 08:30 12:30
WG6: Spin Physics D (BUW)

### D

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Conveners: Barbara Pasquini (University of Pavia), Ernst Sichtermann (Lawrence Berkeley National Laboratory), Yann Bedfer (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 08:30
Measuring the gluon spin contribution to the proton spin in polarized p+p collisions with the PHENIX experiment 30m
A primary goal of the RHIC Spin program has been to measure $Delta g$, the gluon spin contribution to the proton spin, through the double helicity asymmetry, $A_{LL}$. The PHENIX detector is designed with very good electromagnetic calorimetery, allowing for a high statistics $\pi^0$ $A_{LL}$ measurement. PHENIX results from 2005 and 2006 at $\sqrt{s}=200$ GeV have been used in the DSSV global analysis, and were shown to significantly constrain $Delta g$. PHENIX also has made measurements of charged pion, direct photon and heavy flavor $A_{LL}$. Measurements of neutral pions at large rapidity ($3.1<|\eta|<3.9$) will significantly extend the $x$ range probed in PHENIX towards lower $x$. Analysis is also underway for these channels in the large $\sqrt{s}=500$ GeV data taken in 2011-2013. The status of the PHENIX $A_{LL}$ measurements will be presented, including the final results for the 2009 $\pi^0$ $A_{LL}$ at $\sqrt{s}=200$ GeV.
Speaker: Dr Itaru Nakagawa (RIKEN/RBRC)
• 09:00
Probing Sea Quark and Gluon Polarization at STAR 30m
One of the primary goals of the spin program at the Relativistic Heavy Ion Collider (RHIC) is to determine the sea quark and gluon polarization distributions of the proton. The polarization of the sea quarks is probed through the production of $W^{-(+)}$ bosons via the annihilation of $\bar{u}+d\,(\bar{d}+u)$, at leading order. Measurements of the single-spin asymmetry, $A_{L}$, for $W$ and $Z/\gamma^*$ production at $\sqrt{s} = 500$ GeV will be presented, including the new constraints these results place on the antiquark helicity distributions. Recent results on the longitudinal double-spin asymmetry, $A_{LL}$, for inclusive and di-jet production at $\sqrt{s} = 200$ GeV will also be presented. The inclusive jet results provide the first experimental indication of non-zero gluon polarization in the $x$ range probed at RHIC.
Speaker: Justin Stevens (Massachusetts Institute of Technology)
• 09:30
Measurements of parity violating spin asymmetries of the W boson, $W^{\pm} \rightarrow e^{\pm}$, at mid-rapidity with the PHENIX Detector at RHIC 20m
Precision measurements of polarized parton distributions (PDFs) lie at the heart of unraveling the nucleon spin puzzle. The $u$ and $d$ quark distributions are significantly better constrained than the anti-quark $\overline{u}$ and $\overline{d}$ distributions. A clean way to measure the anti-quark distributions directly, without the dilution of poorly known polarized fragmentation functions, is to measure the parity violating production with p+p collisions at $\sqrt{s}$ = 500 GeV and its subsequent decay $W \rightarrow e/\mu$. The PHENIX detector is capable of measuring both in the central and forward rapidity respectively. In this talk we will present the status of $W^{\pm} \rightarrow e^{\pm}$ asymmetry measurement based on $\sim$160 pb$^{-1}$ data collected in 2011, 2012, and 2013.
Speaker: Mr Ciprian Gal (Stony Brook University)
• 09:50
PHENIX W to mu measurements in polarized proton-proton collisions 20m
The Parity violation of the weak interaction allows to use real W production in polarized proton-proton collisions as a tool to select both helicity and flavor of the participating quarks and antiquarks. With W+ production one is mostly sensitive to u and dbar quarks while W- production selects d and ubar quarks. The PHENIX experiment at RHIC has been taking data over the past several years at center of mass energies of around 500 GeV to measure W single spin asymmetries in the inclusive decays into muons at forward rapidities. The latest results will be presented.
Speaker: Dr Ralf Seidl (RIKEN)
• 10:10
Hermes reevaluation of the Parton Distribution of Strange Quarks in the Nucleon 20m
An earlier extraction from the HERMES experiment of the polarization-averaged parton distri- bution of strange quarks in the nucleon has been reevaluated using final data on the multiplicities of charged kaons in semi-inclusive deep-inelastic scattering obtained with a kinematically more com- prehensive method of correcting for experimental effects. General features of the distribution are confirmed, but the rise at low x is less pronounced than previously reported.An earlier extraction from the HERMES experiment of the polarization-averaged parton distri- bution of strange quarks in the nucleon has been reevaluated using final data on the multiplicities of charged kaons in semi-inclusive deep-inelastic scattering obtained with a kinematically more com- prehensive method of correcting for experimental effects. General features of the distribution are confirmed, but the rise at low x is less pronounced than previously reported.
Speaker: Francesca Giordano (UIUC)
• 10:30
Coffee break 30m
• 11:00
First results on A<sub>1</sub><sup>p</sup> and g<sub>1</sub><sup>p</sup> at low x and low Q<sup>2</sup> from COMPASS 30m
The COMPASS experiment at CERN has collected a large sample of about 700 million events of quasi-real photoproduction in polarised μ+-p scattering using a beam momentum of 160 (GeV/c)2 in 2007 and 200 (GeV/c)2 in 2011. The events have a Bjorken scaling variable in the range 0.00004<x<0.04 and a four-momentum transfer squared in the range 0.001<Q2<1 (GeV/c)2. They allow the most accurate determination to date of the longitudinal double spin asymmetry A1p and of the spin-dependent structure function g1p of the proton in the region of low x and low Q2. These data complement our data for a polarised deuteron target. They have an order of magnitude better precision than the previous SMC results. The preliminary results yield non-zero, positive asymmetries A1p and structure function g1p in the full studied ranges of x and ν, the virtual photon energy. It is the first time that spin effects are observed at such low x.
Speaker: Ana Sofia Nunes (LIP Laboratorio de Instrumentacao e Fisica Experimental de Part)
• 11:30
A new LO extraction of gluon polarisation from COMPASS DIS data 30m
A new COMPASS LO evaluation of the gluon polarization in the nucleon is presented. The events in DIS region were re-analyzed and gluon polarization was extracted using the so called all-pT method. In this new method gluon polarization and leading process asymmetry are extracted simultaneously from the same data set using Neural Network approach. The gluon polarization was extracted in three intervals of gluon momentum fraction x_g, while leading process asymmetry in twelve intervals of Bjorken scaling variable x. A reduction of both systematic and statistical uncertainties by more than 50% is achieved comparing to the published result PLB 718 (2013) 922. The results of the current and published analyses are well in agreement. Comparing to the world data of direct gluon polarization extraction in LO analyses the lowest combined statistical and systematic uncertainty is achieved.
Speaker: Marcin Stolarski (LIP)
• 12:00
Single hadron double longitudinal spin asymmetries at $p_T\lt 1$ GeV/c measured at COMPASS 30m
In order to understand why quarks only share about a third of the nucleon spin, quite a few recent experiments have focussed on the measurement of the gluon polarization in the nucleon. To access the gluon polarization, reactions where the Photon Gluon Fusion sensibly contributes are necessary. A way to enhance the PGF contribution in lepton-nucleon or nucleon-nucleon scattering is to study production of hadrons at high transverse momentum where $p_T$ is the hard scale. RHIC has recently measured such double spin asymmetries $A_{LL}(p_T)$ for pion production at high center of mass energies, and inclusion of its data to global fits based on NLO collinear pQCD calculations gives some constraints on the gluon polarization in the range $0.05\lt x_G\lt 0.2\,$ [ref 1]. The validity of the calculations of partonic cross sections at NLO has recently been extended to COMPASS at lower center of mass energies by adding leading-log gluon resummation in the unpolarized case [ref. 2], and they reproduce now within scale uncertainty the cross section for single hadron production as a function of $p_T$ measured recently at COMPASS [ref. 3]. Once extended to the polarized case, $A_{LL}(p_T)$ measurements at COMPASS can also be used to constrain the gluon polarization without uncertainties about validity of the NLO pQCD framework at COMPASS energies. We will present preliminary COMPASS results on double longitudinal spin asymmetries $A_{LL}(p_T)$ for single hadron production measured on the deuteron and the proton at $Q^2\lt1$ GeV$^2$, $p_T\lt 1$ GeV/c and center of mass energy $\sqrt{s}=18$ GeV. All COMPASS data taken from 2002 to 2011 by scattering 160 GeV polarized muons on longitudinally polarized $^6LiD$ and $NH_3$ targets have been used, and the number of hadrons collected with $p_T \lt 1$ GeV/c for this analysis amounts to about 10 millions. The obtained asymmetries will be compared to theoretical predictions of [ref. 4], with possibly inclusion of LL gluon resummation for the polarized case if available in time. [1] E.C. Aschenauer et al., arXiv:1304.0079 [nucl-ex] [2] D.P. Anderle, F. Ringer and W. Vogelsang, Phys. Rev. D87 (2013) 034014 [3] C. Adolph et al. (COMPASS collaboration), Phys. Rev. D88 (2013) 091101 [4] B. Jager, M. Stratmann and W. Vogelsang, Eur. Phys. J C44 (2005) 533
Speaker: Maxime Levillain (CEA/IRFU, Centre d'Etude de Saclay, Gif-sur-Yvette (FR))
• 08:50 12:10
WG2: Small-x, Diffraction and Vector Mesons B (BUW)

### B

#### BUW

Conveners: Lidia Maria Gorlich (Polish Academy of Sciences (PL)), Dr Mario Deile (CERN), Stephane Munier (Ecole polytechnique)
• 08:50
A review of diffraction at HERA 30m
Data in which a proton is tagged along the beampipe after the primary interaction represents the cleanest way to measure diffraction. Data from both H1 and ZEUS collaborations on inclusive diffractive deep inelastic scattering, with a tagged proton, have been combined. Inclusive diffractive deep inelastic scattering can be considered as the exchange of a colourless object and is amenable to QCD fits in which the structure of this object, sometimes called a Pomeron, is determined. Given such processes are expected to factorise, such a Pomeron structure can be used to predict the rates of jet production in e.g. diffractive photoproduction. The comparison of jet data with the predictions of next-to-leading order QCD are discussed in the context of factorising breaking. Another way to study diffraction is through the production of vector mesons which is also characterised by a colourless exchange with the proton which in lowest order QCD is realised as a colourless gluon pair. Therefore consideration of the dependence of the $J/\psi$ cross section on the photon-proton centre-of-mass energy is related to the rise of the square of the gluon density towards low values of Bjorken $x$. Comparisons of HERA data with such theories and other data are presented.
Speaker: Janusz Malka (DESY)
• 09:20
Leptoproduction of vector meson from the small x to the valence region 30m
Many progress have been made in recent years in the field of exclusive electroproduction of mesons. I will describe different theoretical descriptions of this family of processes within the frameworks of kt- factorization, collinear factorization or modified perturbative approach. We systematically compare theoretical expectations to existing data and discuss the impact of QCD evolution equations and the knowledge of meson distribution amplitudes. At last we make some predictions for typical kinematics of electron ion colliders.
• 09:50
b-CGC versus IP-Sat and combined HERA data 20m
We confront the Impact-Parameter dependent Color Glass Condensate dipole (b-CGC) model to the recently released high precision combined HERA data and obtain its parameters. The b-CGC results are then compared to data at small-x for the structure function, the longitudinal structure function, the charm structure function, exclusive vector meson (J/\psi, \phi, \rho) production and Deeply Virtual Compton Scattering (DVCS). We also compare our results with the Impact-Parameter dependent Saturation model (IP-Sat) which has also been recently updated with the combined HERA data. The b-CGC and the IP-Sat models have also been applied to proton-proton and proton-nucleus collisions and provide the basis for modeling initial conditions in heavy ion collisions. We show that most features of inclusive DIS and exclusive diffractive data, including the Q^2, W, |t| and x dependence are correctly reproduced in both models. Nevertheless, the b-CGC and the IP-Sat models give different predictions beyond the current HERA kinematics, namely for the structure functions at very low x and high virtualities Q^2, and for the exclusive diffractive vector meson and DVCS production at high t. We show that both models give approximately similar saturation scale Q_S<1 GeV for the proton in HERA kinematics, and also both models lead to the same conclusion that the typical impact-parameter probed in the total \gamma^{*}p cross-section is about b\approx 2\div 3 GeV^{-1}. We provide some predictions for future electron-proton colliders. This talk is mainly based on: A. H. Rezaeian and I. Schmidt, Phys. Rev. D88, 074016 (2013) [arXiv:1307.0825].
Speaker: Amir Rezaeian (Universidad Tecnica Federico Santa Maria)
• 10:10
Diffractive Dijet Production with Leading Proton in ep Collisions at HERA 20m
The cross section of diffractive process ep$\to$eXp is presented where the system X contains at least two jets and the leading final state proton is tagged in the H1 Very Forward Proton Spectrometer (VFPS). The measurement is performed for untagged photoproduction with Q$^{2}$ < 2 GeV$^{2}$ in photon virtuality and for deep-inelastic-scattering with 4 GeV$^{2}$ < Q$^{2}$ < 80 GeV$^{2}$. The results are compared to next-to-leading order QCD calculations based on diffractive parton distribution functions extracted from measurements of inclusive cross sections in diffractive deep-inelastic-scattering. Results are discussed with focus on the validity of the factorisation theorem for these processes.
Speaker: Mr Radek Zlebcik (Charles University (CZ))
• 10:30
Coffee break 30m
• 11:00
Exclusive dijet production in diffractive deep inelastic scattering at HERA 20m
The exclusive production of dijets in diffractive deep inelastic lepton-proton scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 372 pb$^{-1}$ of $e^\pm p$ data. The measurement has been performed in the kinematic range $Q^2 > 25\,\mathrm{GeV}^2$, $90 < W < 250\,\mathrm{GeV}$ and $x_{\rm I\!P} < 0.01$, where $Q^2$ is the virtuality of exchanged photon, $W$ is the $\gamma^\star p$ centre-of-mass energy and $x_{\rm I\!P}$ is the fraction of the proton momentum taken by the diffractive exchange. Jets have been reconstructed in the photon-Pomeron ($\gamma^\star -{\rm I\!P}$ ) centre-of-mass system frame using the exclusive $k_T$ algorithm. The cross section for the exclusive production of dijets is given as a function of the angle between the plane defined by exchanged photon and dijet system and the plane defined by the incoming and scattered lepton momenta in the $\gamma^*-{\rm I\!P}$ rest frame. It is compared to theoretical predictions of models based on boson-gluon fusion and two-gluon exchange processes.
Speaker: Marcin Guzik
• 11:20
Dijet production with large rapidity gap in deep-inelastic scattering at HERA 20m
In this measurement, the cross section for dijet production in diffractive deep-inelastic scattering is presented. The diffractive events are selected by requiring the presence of a Large Rapidity Gap in the forward region of H1 detector. The data have been collected during the HERA-2 period and correspond to an integrated luminosity of 284 pb$^{-1}$. The data cover the range x_P <0.03 and 4 ≤ Q$^{2}$ ≤ 80 GeV$^{2}$ in photon virtuality. The phase space of the analysis is defined by two inclusive jets found by the k_T cluster algorithm in the hadronic centre-of-mass system. The leading and sub-leading jets are required to have E_T$^{*jet1}$ > 5.5 GeV and E_T$^{*jet2}$ > 4 GeV, respectively and to lie within LAr calorimeter acceptance, i.e. -1 < η$^{jet1,2}$ < 2. Differential cross sections are compared to QCD Next-to-leading calculations corrected to the level of stable hadrons.
Speaker: Boris Pokorny (Charles University Prague)
• 11:40
Exclusive Photoproduction of Rho Meson with Leading Neutron at HERA 30m
The first measurement of exclusive photoproduction of rho meson associated with the leading neutron at HERA is presented. The data are taken with the H1 detector in the years 2006-2007 and correspond to an integrated luminosity of 1.16 pb-1. The rho mesons are reconstructed from decay pions in the central tracking chamber, while the leading neutrons, carrying a large fraction of the incoming proton momentum x_L>0.4, are detected in the Forward Neutron Calorimeter. The phase space of the measurement is restricted to by photon virtualities Q$^{2}$<2 GeV$^{2}$, total energies of the gamma-p system 20 < W_gp < 100 GeV and polar angles of the leading neutrons, theta_n < 0.75 mrad. The cross section of the reaction gamma+p -> rho+n+Y, where Y is a small mass system escaping undetected in the proton direction, is measured as a function of the neutron energy, the invariant mass of the pi+pi- system and the transverse momentum and the pseudorapidity of the rho meson. The data are interpreted in terms of a double peripheral process, involving a pion exchange at the proton vertex followed by elastic photoproducton of a rho meson on a virtual pion.
Speaker: Sergey Levonian (Deutsches Elektronen-Synchrotron (DE))
• 09:00 12:10
WG4: QCD and Hadronic Final States F (BUW)

### F

#### BUW

Conveners: Daniel Britzger (Deutsches Elektronen-Synchrotron (DE)), Konstantinos Kousouris (CERN), Vladimir Braun (University of Regensburg)
• 09:00
Welcome from the WG4 conveners 5m
• 09:05
Light meson production in e+e- annihilation at BABAR 20m
The BABAR Collaboration has an intensive program studying hadronic cross sections at low-energy e+e- annihilations, accessible via initial-state radiation. These measurements allow significant improvements in the precision of the predicted value of the muon anomalous magnetic moment. We report here the results of recent studies on a number of final states, as e+e- -> K+K-, e+e- -> K0S K0L, and e+e- -> 4 hadrons.
Speaker: Gianluigi Cibinetto (INFN Ferrara)
• 09:25
Measurement of the jet production cross section at 7 TeV 20m
Measurements of jet production are sensitive to the strong coupling constant, next-to-leading order perturbative calculations and parton distribution functions. The measurements are obtained using data corresponding to an integrated luminosity of 4.5 fb −1, recorded by the ATLAS detector in 2011. Cross sections are measured up to 5 TeV dijet mass using jets reconstructed with the anti-kt algorithm for values of the jet radius parameter of 0.4 and 0.6. The quantitative comparison of data and theoretical predictions obtained using various parameterizations of the parton distribution functions is performed using a frequentist method.
Speaker: Gagik Vardanyan (ANSL (Yerevan Physics Institute) (AM))
• 09:45
Jet production measurements at CMS 20m
We present CMS results related to jet production cross sections, which pose a central test to perturbative QCD predictions. Results include recent jet, dijet, multijet differential cross section and hadronic event shape measurements performed with 2011 data taken at center-of-mass energy of 7 TeV and 2012 data taken at 8 TeV.
Speaker: Dr Panos Kokkas (University of Ioannina (GR))
• 10:05
Search for QCD Instantons using the H1 experiment at HERA 20m
Signals of QCD instanton-induced processes are searched for in deep-inelastic scattering (DIS) at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable x > 10$^{-3}$, the inelasticity 0.2< y < 0.7 and the photon virtuality 150 < Q$^{2}$ < 15000 GeV$^{2}$. The search is performed using H1 data corresponding to an integrated luminosity of 350 pb$^{-1}$. Several observables of the hadronic final state of the events are exploited to identify a potentially instanton-enriched domain. Two Monte Carlo models, RAPGAP and ARIADNE, are used to estimate the background from the standard DIS processes, and the instanton-induced scattering processes are modeled by the program QCDINS. In order to extract the expected signal a multivariate data analysis technique is used.
Speaker: Pawel Sopicki (IFJ PAN)
• 10:25
Coffee break 25m
• 10:50
Photoproduction of isolated photons, inclusively and with a jet, at HERA 20m
The photoproduction of isolated photons, both inclusive and together with a jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of $374\, \mathrm{pb}^{-1}$. Differential cross sections are presented in the isolated-photon transverse-energy and pseudorapidity ranges $6 < E_T^{\gamma} < 15$ GeV and $-0.7 < \eta^{\gamma} < 0.9$, and for jet transverse-energy and pseudorapidity ranges $4 < E_T^{\rm jet} < 35$ GeV and $-1.5 < \eta^{\rm jet} < 1.8$, for exchanged-photon virtualities $Q^2 < 1$ GeV$^2$. Differential cross sections are also presented for inclusive isolated-photon production as functions of the transverse energy and pseudorapidity of the photon. Higher-order theoretical calculations are compared to the results.
Speaker: Oleg Kuprash (DESY)
• 11:10
Further studies of prompt photons in photoproduction at HERA 20m
The ZEUS Collaboration present further measurements of prompt photons produced with jets in photoproduction, studying a variety of kinematic variables that are sensitive to different aspects of the event dynamics. Cross sections are given in terms of the collinearity of the photon and the jet, the fraction of the proton energy involved in the interaction, and the pseudorapidity difference between the photon and the jet. These and other variables are also studied for different ranges of $x_\gamma^{\rm meas}$, the fraction of the photon energy involved in the interaction, in order to enhance the direct and resolved photon components of the process.
Speaker: Oleg Kuprash (DESY)
• 11:30
Measurement of photon and photon+jet production cross sections at 7 TeV and constraints to PDFs 20m
Measurement of the inclusive photon production performed by the ATLAS collaboration using 4.6 fb-1 of sqrt(s)=7 TeV collision data is reported. Comparisons to the data of next-to-leading order QCD calculations MCFM and JetPhox with different PDFs are presented. The theoretical uncertainties, including scale, strong coupling, and PDF uncertainties are evaluated. The compatibility between data and theory is assessed by χ2 evaluation, taking into account the correlations between systematic uncertainties. The cross sections for photons produced in association with jets are also measured by the ATLAS collaboration at sqrt(s)=7 TeV as functions of photon and jet kinematics and are compared to next-to-leading-order QCD calculations.
• 11:50
Analysis of Feynman Scaling in Photon and Neutron Production in the Very Forward Direction in Deep-Inelastic Scattering at HERA 20m
Measurements of the normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic positron proton scattering at HERA are presented as a function of the variable Feynman-x. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 126 pb$^{-1}$. The analysis covers the range of negative four momentum transfer squared at the positron vertex 6 < Q$^2$ < 100 GeV$^2$, inelasticity 0.05 < y < 0.6 and the centre-of-mass energy of the virtual photon-proton system 70 < W < 245 GeV. The dependence of the cross sections on W is investigated. Predictions of models of deep inelastic scattering and models of the hadronic interactions of high energy cosmic rays are compared to the measured cross sections.
Speaker: Jan Olsson
• 12:40 14:00
Lunch break 1h 20m BUW

#### BUW

• 14:00 18:30
WG2: Small-x, Diffraction and Vector Mesons B (BUW)

### B

#### BUW

Conveners: Lidia Maria Gorlich (Polish Academy of Sciences (PL)), Dr Mario Deile (CERN), Stephane Munier (Ecole polytechnique)
• 14:00
Predictions of Diffractive and Total Cross Sections at LHC Confirmed by Measurements 30m
Predictions of diffractive proton-proton cross sections at LHC, and of the total and total-inelastic proton-proton cross sections based on the RENORM unitarization model, also known as the MBR (minimum-bias-Rockefeller) model implemented in PYTHIA8-MBR, are confirmed by recent LHC measurements. Several other available diffraction models are discussed, highlighting differences among them and PYTHIA8-MBR regarding rapidity-gap and final-state distributions.
Speaker: Prof. Goulianos Konstantin (The Rockefeller University)
• 14:30
Elastic and Diffractive Proton-Proton Scattering Measurements by TOTEM at the LHC 30m
The TOTEM experiment at the LHC has measured the elastic proton-proton cross-section at sqrt(s) = 7 TeV and 8 TeV in a large range of the four-momentum transfer t. At 8 TeV the measurement reaches into the Coulomb-Nuclear Interference region, providing insight into the nuclear scattering phase and its functional dependence on t. Via the optical theorem, the measurement of low-|t| elastic scattering has enabled the determination of the total p-p cross-section with different, systematically complementary approaches. TOTEM has also performed measurements of diffractive processes, either with leading protons (Single and Central Diffraction) or purely based on the forward trackers T1 and T2 (Double Diffraction).
Speaker: Dr Mario Deile (CERN)
• 15:00
Central Exclusive Production in hadron collisions 30m
Central exclusive production (CEP) processes in high-energy proton-(anti)proton collisions offer a very promising framework within which to study both novel aspects of QCD and new physics signals. We discuss the charmonium production applying the Durham pQCD-based model for evaluation of the rates and proton momentum correlations at the Tevatron and LHC energies and compare the results with the existing experimental data. We also present new results of a recent novel application of the 'hard exclusive' PT formalism to the CEP of dijets, diphotons and to dimeson CEP which, in particular, opens a way to probe the gluon component of the meson wave-functions.
Speaker: Valery Khoze (University of Durham (GB))
• 15:30
Diffractive and exclusive measurements at CMS 30m
We present updated measurements of soft single- and double-diffractive cross sections, and of forward rapidity gap cross section, as well as the measurement of the fraction of events with a forward rapidity gap and a jet produced at central rapidity at 7 TeV at the LHC. We compare the results to other measurements and to theoretical predictions implemented in various Monte Carlo simulations. We present recent CMS measurements of photon-induced processes and Central Exclusive Production, using data collected during Run 1 of the LHC. The results include studies of exclusive WW production via photon-photon exchange, using ≥5 fb-1 of pp data collected by the CMS detector. Exclusive WW events are selected by requiring a muon and electron from the same vertex with no associated charged tracks. The tail of the dilepton transverse momentum is studied for deviations from the Standard Model. The results are interpreted in terms of limits of anomalous quartic gauge couplings
Speaker: Dr Marta Ruspa (Universita e INFN (IT))
• 16:00
Coffee break 30m
• 16:30
After the first LHC Long Shutdown, TOTEM and CMS will join forces to create a combined apparatus with the largest rapidity coverage and with a very performing two-arm proton spectrometer. Focussing on the process of central diffraction opens unique opportunities for exploring QCD in new phase space regions, for performing competitive electroweak measurements, and for the search for new physics. First studies of central diffraction and, in particular, diffractive dijet production in special runs in 2012 have provided the proof of concept, but demonstrate that even at moderate luminosities a key issue to be overcome in physics with leading protons is the pileup of several events per bunch crossing. This talk will outline the physics programme, the operational challenges and the strategy for increasing the reachable integrated luminosity and rendering the apparatus capable of resolving event pileup.
Speaker: Valentina Avati (CERN)
• 16:55
AFP - Forward Protons Detectors for ATLAS 25m
The “ATLAS Forward Proton (AFP) detectors” is a project of upgrading the ATLAS experiment with additional detectors allowing measurements of the forward protons scattered diffractively or electromagnetically. A general overview of the AFP detector system and its capabilities will be given. The AFP physics programme will be discussed, including soft diffraction, hard inclusive diffraction, exclusive diffraction and exotics studies in two-photon exchange processes. Finally, the current status of the project will be presented.
Speaker: Rafal Staszewski (IFJ PAN Cracow (PL))
• 17:20
Quarkonia production at LHCb 30m
Studies of quarkonia production in the forward region provide important tests of NRQCD. The LHCb experiment has collected a dataset corresponding to an integrated luminosity of about 3 fb-l in proton-proton collisions at sqrt(s)= 2.76, 7 and 8 TeV. We present studies of the production and polarisation of the J/psi, psi(2S) and chi_c charmonium states as well as those of Upsilon and chi_b bottomonia. Absolute and relative production cross-sections are presented and compared to the most recent theoretical predictions when available. The latest years have seen a resurrection of interest in searches for exotic states motivated by tantalising observations by Belle and CDF. Using the data collected at pp collisions at 7 and 8 TeV by the LHCb experiment we present studies of the X(3872) properties including its decay rate to Psi(2S)gamma, as well as studies of putative states such as the Z(4430)+.
Speaker: Marco Adinolfi (University of Bristol (GB))
• 17:50
Exclusive J/psi and psi(2S) vector meson production 20m
An updated measurement of exclusive J/psi and psi(2S) vector meson production using 1/fb at 7 TeV is presented. The measured integrated and differential cross-sections are compared to several theoretical predictions. The data are sufficiently sensitive to distinguish between LO and 'NLO' predictions. The forward reach of the LHCb detector probes small values of x, and these results can be used to constrain the gluon PDF down to x=5E-6. The data are also compared to models that include saturation effects, which may become important at such low x-values. Comparisons are also made to photoproduction results from HERA and fixed target experiments.
Speaker: Tomasz Szumlak (AGH University of Science and Technology (PL))
• 18:10
Phi meson production measurement with ATLAS 20m
A measurement of the differential production cross section of the φ(1020)-meson at sqrt(s)=7 TeV using pp collision data collected with the ATLAS experiment is presented. The φ(1020)-meson selection is based on the identification of kaons by their energy loss in the pixel detector. The differential cross section is measured as a function of the transverse momentum and rapidity. The measurement is compared to the prediction of various MC simulations.
Speaker: Lucie De Nooij (NIKHEF (NL))
• 14:00 18:30
WG3+WG5 Joint Session: EW Physics and BSM + Heavy Flavours Auditorium (BUW)

### Auditorium

#### BUW

Conveners: Anna Kaczmarska (Polish Academy of Sciences (PL)), Anze Zupanc (Jozef Stefan Institute), Krzysztof Turzynski (University of Warsaw), Martin Gorbahn (Liverpool University), Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR)), Vanya Belyaev (ITEP Institute for Theoretical and Experimental Physics (RU))
• 14:00
Top quark cross section measurements with CMS 24m
Measurements of the inclusive top quark pair production cross section at 7 TeV and 8 TeV are presented, performed using CMS data collected in 2011 and 2012. The total cross section is measured in the lepton+jets, dilepton and fully hadronic channels, including the tau-dilepton and tau+jets modes. Indirect constraints on both the top quark mass and alpha_s are obtained through their relation to the inclusive cross section. First measurements of top quark pair production with additional b-quarks in the final state are also presented. Differential cross sections are measured and are given as functions of various kinematic observables, including the transverse momentum and rapidity of the (anti)top quark and the top-antitop system and the jets and leptons of the event final state. Multiplicity and kinematic distributions of the jets produced in addition to the top pair are also investigated. The results are combined and confronted with precise theory calculations.
Speaker: Javier Fernandez Menendez (Universidad de Oviedo (ES))
• 14:24
Top quark cross section measurements with ATLAS 24m
Measurements of the differential top quark pair production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented. The measurements are performed requiring one electron or muon in the final state and are carried out differentially in the reconstructed top transverse momentum and the invariant mass, rapidity and transverse momentum of the top pair system. This measurement probes our understanding of top pair production in the TeV regime and is compared to recent Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations. The data show sensitivity to parton density functions.
Speaker: Prof. Patrick Skubic (University of Oklahoma)
• 14:48
Single top quark production with CMS 24m
Measurements of single top quark production are presented, performed using CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV. The cross sections for the electroweak production of single top quarks in the t-channel and in association with W-bosons is measured and the results are used to place constraints on the CKM matrix element Vtb. In the t-channel the ratio of top and anti-top production cross sections is determined and compared with predictions from different parton density distribution functions. Measurements of top quark properties in single top quark production are also presented. The results include the W-helicity in top quark decay and the searches for s-channel production and for anomalous couplings.
Speaker: Alberto Orso Maria Iorio (Universita e INFN (IT))
• 15:12
Single Top quark production cross section using the ATLAS detector at the LHC 24m
Measurements of single top-quark production cross section in proton proton collisions at 7 and 8 TeV are presented. In the leading order process, a W boson is exchanged in the t-channel. The single top-quark and anti-top total production cross sections, their ratio, as well as a measurement of the inclusive production cross section is presented. Differential cross sections for the top and anti-top processes are measured as a function of the transverse momentum and the absolute value of the rapidity of top and anti-top, respectively. In addition, a measurement of the production cross section of a single top quark in association with a W boson is presented. All measurements are compared to NLO and NLO+NNLO calculations and the CKM matrix element |Vtb| is determined. In addition, the s-channel production is explored and limits on exotic production in single top quark processes are discussed. This includes the search for flavor changing neutral currents and the search for additional W’ bosons in the s-channel.
Speaker: Caterina Monini (Centre National de la Recherche Scientifique (FR))
• 15:36
Uncertainties on Higgs and ttbar predictions at the LHC from CTEQ-TEA Global Analysis 24m
We study the uncertainties of the Higgs boson and ttbar production cross sections at the LHC arising from the uncertainties of the parton distribution functions (PDFs) and of the value of the strong coupling constant αs(MZ). We investigate the robustness of the commonly-used Hessian approach by comparing with the more-general Lagrange Multiplier method within the CTEQ-TEA global analysis, for the two processes.
Speaker: Carl Schmidt (Michigan State University)
• 16:00
Coffee Break 30m
• 16:30
Top quark pair properties - spin correlations, top quark pair asymmetry and complex final states using the ATLAS detector at the LHC 23m
In proton-proton collisions at the LHC, pairs of top and anti-top quarks are expected to be mostly produced through gluon fusion. Making use of the large number of top quark pairs collected, we present measurements of the spin correlation between top and anti-top quarks using several variables and discuss their sensitivity to new physics. In addition, we present measurements of the top quark polarisation predicted in models with CP-conserving and CP-violating processes.
Speaker: Ralph Schafer (Deutsches Elektronen-Synchrotron (DE))
• 16:53
Associated production of heavy flavour final state and a vector boson and search for H->bb 23m
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 b-mesons 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 physics studies and Beyond the Standard Model searches. 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, Zb(b) cross sections and angular correlations are presented, as well as Wbb production cross-section. Finally, the study of the associated production of a c-quark and a W boson with respect to the W charge and W plus light jets are also presented, allowing to probe and constrain the strange quark content of the proton.
Speaker: Roberto Castello (Universite Catholique de Louvain (UCL) (BE))
• 17:16
Intrinsic top quark properties - top mass, charge and W helicity using the ATLAS detector at the LHC 23m
Properties of the top quark are measured in proton-proton collisions data at 7 and 8 TeV. Measurements of the top-quark mass are presented. Other properties like the charge of the top quark, as well as of the polarization of W bosons in top quark decays to probe the structure of the Wtb-vertex are measured and constraints on anomalous couplings derived. A search for flavour changing neutral current processes in top quark decays is also presented.
Speaker: Riccardo Di Sipio (Universita e INFN (IT))
• 17:39
Top quark mass measurements with CMS 23m
Measurements of the top quark mass are presented, obtained from CMS data collected in proton proton collisions at the LHC at centre-of-mass energies of 7 TeV and 8 TeV. The mass of the top quark is measured using several methods and channels, including the reconstructed invariant mass distribution of the top quark, an analysis of endpoint spectra as well as measurements from shapes of top quark decay distributions. The dependence of the mass measurement on the kinematic phase space is investigated. The results of the various channels are combined and compared to the world average. The top mass and also alpha_s are extracted from the top pair cross section measured at CMS.
Speaker: Elvire Bouvier (Universite Claude Bernard-Lyon I (FR))
• 18:02
Top quarks as a probe for heavy new physics 28m
The heaviest fermion is expected to couple strongly to new physics and appears therefore a natural probe in many BSM scenario. Moreover, top physics has now enter in a precision era thanks to the huge amount of top quarks produced at hadron colliders, advanced experimental methods and accurate theoretical predictions. In this talk, we will used effective field theory to search for heavy new physics in a model independent way. This method can also be used to quantify the room left for new physics if no deviation from the SM is found.
Speaker: Celine Degrande (UIUC)
• 14:00 18:10
WG4: QCD and Hadronic Final States F (BUW)

### F

#### BUW

Conveners: Daniel Britzger (Deutsches Elektronen-Synchrotron (DE)), Konstantinos Kousouris (CERN), Vladimir Braun (University of Regensburg)
• 14:00
Production of top pair events with additional radiation using the ATLAS detector at the LHC. 20m
The large centre-of-mass energy available at the proton-proton collider LHC allows for the copious production of top quark pairs in association with other final state particles at high transverse momentum. The ATLAS experiment has measured several final state observables that are sensitive to additional parton radiation in top anti-top quark final states. Examples are the multiplicity of jets for various transverse momentum thresholds or the probability to emit jets above a given threshold in a fixed rapidity region. These measurements are compared to modern Monte Carlo generators based on NLO QCD matrix element or LO multi-leg matrix elements. The data are able to constrain the uncertainty on the modelling of the top pair production mechanism. We also discuss top production in association with photons and Z bosons. In addition, we the discuss production of top quark pairs in association with heavy quarks (beauty and charm).
Speaker: Lorenzo Bellagamba (Universita e INFN (IT))
• 14:20
Measurement of the transverse momentum of the Z boson and NLO MC tuning 20m
Measurement of the transverse momentum of the Z boson performed by the ATLAS collaboration is reported for sqrt(s) = 7 TeV. The measurement is sensitive to soft resummation effects for small momentum transfers and to multiple hard jet emissions for large momentum transfers, probing QCD in a unique way. The data are used to tune NLO plus parton shower Monte Carlo simulations.
Speaker: Homero Martinez Bruzual (Universite de Paris-Sud 11 (FR))
• 14:40
Associated production of a vector boson and jets. 20m
The production cross section of highly boosted vector bosons (V = W, Z or γ) recoiling against jets is studied, with CMS data, differentially as function of the transverse momentum and angular correlations of the final state particles. The measurements are confronted with different state-of-the-art theory predictions that include next-to-leading order calculations and matrix-element plus parton shower event simulations.
Speaker: Mr Kadir Ocalan (Middle East Technical University (TR))
• 15:00
Associated Z boson production in the forward region 20m
A measurement of the Z(→μ+μ−)+jet production cross-section in pp collisions at a centre-of-mass energy s√=7 TeV is presented. The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction. We also report about the observation of associated production of a Z boson with a D meson
Speaker: Marek Sirendi (University of Cambridge (GB))
• 15:20
Measurement of charged particle multiplicities and densities in pp collisions at 7 TeV in the forward region 20m
Charged particle multiplicities are studied in proton-proton collisions in the forward region at a centre-of-mass energy of sqrt(s) = 7 TeV with data collected in 2010 by the LHCb experiment. The forward spectrometer allows access to a kinematic range of 2.0 < eta < 4.8 in pseudorapidity, momenta down to 2 GeV/c and transverse momenta down to 0.2 GeV/c. The results are presented as functions of pseudorapidity and transverse momentum and are compared to predictions from several Monte Carlo event generators.
Speaker: Dr Paul Michael Szczypka (Ecole Polytechnique Federale de Lausanne (CH))
• 15:40
Coffee break 30m
• 16:10
Double charmed meson production at the LHC: Single- versus double-parton scattering mechanism 20m
We compare results of exact calculations of single-parton scattering (SPS) and double-parton scattering (DPS) for production of $c \bar c c \bar c$ and for $D-D$ meson correlations [1]. Each step of DPS is calculated within $k_t$-factorization approach, i.e. effectively including next-to-leading order corrections. The SPS calculations are performed in collinear approximation with exact matrix element for $g g \to c \bar c c \bar c$ subprocess. The new results are compared with results of previous calculation with approximate matrix elements in high-energy approximation. The cross section for the exact calculation is bigger only at small invariant masses and small rapidity difference between two $c$ quarks (or two $\bar c$ antiquarks). We compare correlations in rapidities of two $c$ (or two $\bar c$) for DPS and SPS contributions. Finally we compare our predictions for $DD$ meson pairs with recent results of the LHCb collaboration for invariant mass, rapidity distance between mesons and dimeson invariant mass. The predicted shapes are similar to the measured ones, however, some strength seems to be lacking. Possible missing contribution within the framework of DPS mechanism is suggested. Our new calulations clearly confirm the dominance of DPS in the production of events with double charm. [1] A. van Hameren, R. Maciula and A. Szczurek, arXiv:1402.6972 [hep-ph].
Speakers: Antoni Szczurek (Institute of Nuclear Physics), Rafal Maciula (Institute of Nuclear Physics PAN)
• 16:30
First measurement of associated vector boson plus prompt charmonium production at the ATLAS experiment 20m
We present evidence of associated vector boson+prompt J/psi production and measure its production rate. This is a key observable to further the understanding of quarkonium production mechanisms. We estimate the relative contributions to the signal from single and double parton scattering and discuss possible implications of this novel final state for study of multiple parton interactions. Single parton scattering cross-sections are compared to cutting-edge theoretical calculations in the colour singlet and colour octet formalisms.
Speaker: Hannah Ruth Arnold (Albert-Ludwigs-Universitaet Freiburg (DE))
• 16:50
Jet properties of hadronically-decaying massive particles 20m
The identification and study of jets originated from the hadronic decays of massive particles, like vector bosons or top quark provide a direct test of QCD calculations of gluon and quark radiation and validate novel techniques of jet shapes and jet substructure for reducing the sensitivity to soft QCD and to multiple proton-proton collisions. A measurement of jet shapes in t-tbar final states using data recorded by the ATLAS detector is presented. Samples of events with top-quark pairs are selected in both the semileptonic and dileptonic decay modes and the differential and integrated shapes of the b-quark jets resulting from the top-quark decays are compared with those of the light-quark jets from the hadronic W-boson decays W -> q¯q' in the semileptonic channel.
Speaker: Rebecca Thalatta Chislett (University of London (GB))
• 17:10
Detailed study of the Ke4 decay mode properties 20m
The NA48/2 Collaboration at CERN has accumulated unprecedented statistics of rare kaon decays in the Ke4 modes Ke4(+-) to pi+ pi- e nu and Ke4(00) to pi0 pi0 e nu with ~one percent background contamination. The detailed study of form factors is sensitive to small isospin symmetry breaking effects. This brings new inputs to low energy QCD description and crucial tests of predictions from Chiral Perturbation Theory and lattice QCD calculations.
Speaker: Milena Hristova Misheva (Joint Inst. for Nuclear Research (RU))
• 17:30
Measurement of the rare decay K+- --> pi+- gamma gamma 20m
New final results from an analysis of about 400 K+- --> pi+- gamma gamma rare decay candidates collected by the NA48/2 and NA62 experiments at CERN during low intensity runs with minimum bias trigger configurations are presented. The results include a model-independent decay rate measurement and fits to Chiral Perturbation Theory (ChPT) description. The data support the ChPT prediction for a cusp in the di-photon invariant mass spectrum at the two pion threshold.
Speaker: Plamen Rumenov Petrov (Universite Catholique de Louvain (UCL) (BE))
• 17:50
5 min. extra time 5m
• 14:00 18:30
WG6: Spin Physics D (BUW)

### D

#### BUW

Conveners: Barbara Pasquini (University of Pavia), Ernst Sichtermann (Lawrence Berkeley National Laboratory), Yann Bedfer (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 14:00
New COMPASS results on the spin structure function $g_1^p$, and QCD fit 30m
The COMPASS experiment at CERN SPS has taken data with a polarised muon beam scattering off a polarised NH$_3$ target in 2011. The beam energy has been increased to 200 GeV compared to 160 GeV in 2007 and thus, higher values of $Q^2$ and lower values of $x$ are reached. We will present our results on the longitudinal double spin asymmetry $A_1^p$ and the spin-dependent structure function $g_1^p$. These results are used in a NLO QCD fit to the world data to obtain the polarised parton distributions and also to update our results on the Bjorken sum rule, connecting the integral of the non-singlet structure function with the ratio of the weak coupling constants. Supported by BMBF under the contract 05P12UMCC1 and GRK Symmetry Breaking (DFG/GRK 1581)
Speaker: Malte Christian Wilfert (Johannes-Gutenberg-Universitaet Mainz (DE))
• 14:30
The JAM fit of spin-dependent PDFs 30m
We present results of a new next-to-leading order fit of spin-dependent parton distribution functions from the most recent world data on inclusive polarized deep-inelastic scattering, focusing in particular on the large-x and low-Q2 regions. By directly fitting polarization asymmetries we eliminate biases introduced by using polarized structure function data extracted under nonuniform assumptions for the unpolarized structure functions. For analysis of the large-x data we implement nuclear smearing corrections for Deuteron and 3He nuclei, and systematically include target mass and higher twist corrections to the g1 and g2 structure functions at low Q2. We also explore the effects of Q2 and W2 cuts in the data sets, and the potential impact of future data on the behavior of the spin-dependent parton distributions.
Speaker: Alberto Accardi (Hampton U. and Jefferson Lab)
• 15:00
Unbiased helicity-dependent parton distributions with polarized collider data 30m
We present an unbiased global determination of spin-dependent parton distribution functions and their uncertainties using the NNPDF methodology: NNPDFpol1.1. As compared to our previous determination, NNPDFpol1.0, longitudinally polarized deep-inelastic scattering data are now supplemented with the most recent polarized hadron collider data for inclusive jet and W boson production from STAR and PHENIX experiments at RHIC. Polarized W production data provide a handle on the polarized quark-antiquark separation, while inclusive jet production data allow us to substantially improve our determination of the medium- and large-x polarized gluon. We study the phenomenological implications of the NNPDFpol1.1 set, in particular concerning the nucleon spin content.
Speaker: Emanuele Roberto Nocera (Università degli Studi di Milano & INFN Milano,Italy)
• 15:30
Phenomenological aspects of evolution in transverse momentum dependent PDF's and fragmentation 30m
In this talk I will review and update several characteristic of TMD evolution for PDF's and extend the formalism to include fragmentation. I will present also a phenomenological data analisis for unpolarized TMDPDF using evolution at NNLL.
Speaker: Prof. Ignazio Scimemi (Departamento de Fısica Teorica II, Universidad Complute nse de Madrid)
• 16:00
COMPASS results on the transverse spin asymmetry in identified dihadron production in SIDIS 30m
The parton distribution function $h_{1}^{q}(x)$ of a transversely polarized quark $q$ inside a transversely polarized nucleon, is chiral-odd and therefore not accessible in inclusive deep-inelastic scattering. It can however be observed in semi-inclusive deep-inelastic scattering (SIDIS) in combination with another chiral-odd function, for instance the dihadron interference fragmentation function (DiFF) $H_{1}^{\triangleleft q}$. The $160\,\mbox{GeV}/c$ polarized muon beam of CERN's M2 beamline allows COMPASS to investigate transverse spin effects using polarized solid-state targets. In this contribution an overview of COMPASS results for the azimuthal asymmetry in identified dihadron production is given. Pions and kaons were identified by a RICH detector. Recently, the full set of this asymmetry from the COMPASS data on the deuteron and the proton target became available. All data, including early data sets, were analyzed using the same methods and requirements. The results are compared to model predictions and HERMES data. Furthermore an extraction of the transversity distribution function $h_{1}(x)$ for $u$ and $d$ quarks was carried out with this full data set.
Speaker: Christopher Braun (Friedrich-Alexander-Univ. Erlangen (DE))
• 16:30
Coffee break 30m
• 17:00
HERMES results on transverse target single-spin asymmetries in inclusive electroproduction of charged pions and kaons 25m
Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle $\psi$ about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum $p_T$ relative to the direction of the incident beam, and the Feynman variable $x_F$. The $\sin\psi$ amplitudes are positive for $\pi^{+}$ and $K^{+}$, slightly negative for $\pi^{-}$ and consistent with zero for $K^{-}$, with particular $p_{T}$ but weak $x_{F}$ dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer.
Speaker: Klaus Rith (University of Eralngen-Nürnberg)
• 17:25
Transverse-spin gluon distribution function 25m
We define the novel polarized PDF, the transverse-spin gluon distribution function $G_T(x)$, as the nucleon matrix element of the gauge-invariant bilocal light-cone operator in QCD, and discuss their properties. $G_T(x)$ is the gluonic analogue of the transverse-spin quark distribution function $g_T(x)$ that contributes to the transverse-spin structure function $g_2(x, Q^2)$ in the DIS of a longitudinally-polarized lepton off a transversely-polarized nucleon target. These distributions, $g_T(x)$ and $G_T(x)$, are relevant to the “angular momentum sum rule” for the transversely-polarized nucleon, because the integral of $g_T(x)$ ($G_T(x)$) over $x$ gives the quark-spin (gluon-spin) contribution arising in the partonic decomposition of the transverse nucleon spin. We show that the transverse-spin gluon distribution function $G_T(x)$ can be expressed as the sum of the two types of gluonic light-cone correlators: one is the correlator of the chromoelectric fields and the other is the correlator of the chromomagnetic fields; both of these correlators are of twist-three and correspond to the helicity flip by one unit (i.e., correlator between the chromoelectric (chromomagnetic) field carrying the helicity zero and the chromoelectric (chromomagnetic) field carrying the helicity +1 or -1), similarly as the helicity-flip nature of the transverse-spin quark distribution $g_T(x)$. We note that the former (chromoelectric) correlator coincides with the twist-three gluon distribution $G_3(x)$ introduced by X. Ji in Phys. Lett. B289 (1992) 137, but the relevance of the latter (chromomagnetic) correlator has not been noticed so far. The classification of the collinear PDFs is now completed up to twist-three with this chromomagnetic correlator. We derive the moment sum rules for $G_T(x)$ and the corresponding operator product expansion, revealing that $G_T(x)$ receives the three-gluon correlation effects. This work is based on our paper JHEP1302 (2013) 003 and the recent new results.
Speaker: Kazuhiro Tanaka
• 17:50
Orbital angular momentum in the nucleon 25m
In the last decade, it has been realized that the orbital angular momentum of partons inside the nucleon plays a major role. It contributes significantly to nucleon properties and is at the origin of many asymmetries observed in spin physics. It is therefore of paramount importance to determine this quantity if we want to understand the nucleon internal structure and experimental observables. This triggered numerous discussions and controversies about the proper definition of orbital angular momentum in a relativistic gauge theory and its extraction from experimental data. We summarize the present situation and discuss recent developments in this field.
Speaker: Dr Cédric Lorcé (IPN Orsay and IFPA Liège)
• 14:00 18:10
WG7: Future experiments E (BUW)

### E

#### BUW

Conveners: Abhay Deshpande (Stony Brook University), Alexei Prokudin (Jefferson Lab), Alice Valkarova (Charles University (CZ))
• 14:00
LHeC accelerator development 20m
The Large Hadron Electron Collider (LHeC) is a proposed facility which will exploit the LHC beams for electron-proton/nucleus scattering, using a new 60 GeV electron accelerator. Following the release of its detailed technical design report in 2012, the configuration of a linac with racetrack shape has been chosen for its default design. Further work has been pursued in order to adapt the electron and high luminosity optics and beam parameters, to achieve performance levels close to 10$^{34}$ cm$^{-2}$ s$^{-1}$ as is desirable for precision Higgs physics with the LHeC. In parallel, work has focused on the design of an LHeC Test Facility at CERN and to validate and prepare the Energy Recovery Linac operation mode for the LHeC and to develop the required Superconducting RF technologies. The talk presents an overview on the design, recent activities and an outlook for further developments.
Speaker: Emilia Cruz Alaniz (University of Liverpool)
• 14:20
Electroweak and top physics at energy frontier DIS 20m
The Large Hadron Electron Collider (LHeC) is a proposed facility which will exploit the LHC and FCC proton beams for electron-proton scattering, using either a new 60 GeV electron accelerator or one of the FCC 'ee' beams. This contribution presents the outstanding possibilities for electroweak precision measurements of the light quark weak neutral current couplings and of the electroweak mixing angle, below the Z mass and extending to a few TeV scale with the FCC ep collider, which cannot be probed elsewhere with such a precision. The perspectives for top measurements in DIS will also be presented.
Speaker: Christian Schwanenberger (University of Manchester (GB))
• 14:40
Parton distributions in the proton from the LHeC 20m
Due to the high energy and luminosity, the LHeC, for the first time, permits the unfolding of all parton momentum distributions: six quarks (including top) and gluon, over five orders of magnitude. It also determines the strong coupling constant with unprecedented precision, including a unique program for settling the heavy quark densities. The complete determination of the proton PDFs has important consequences for the BSM and Higgs program at the LHC, and in the future for the FCC pp program. This talk will review all these aspects of the LHeC physics program.
Speaker: Voica Ana Maria Radescu (Deutsches Elektronen-Synchrotron (DE))
• 15:00
Exclusive vector meson production at high energies and gluon saturation 20m
We investigate exclusive diffractive photoproduction of vector mesons (J/ψ, ϕ and ρ) off protons in high-energy collisions. We confront saturation-based results for diffractive J/ψ photoproduction with all available data including recent ones from HERA and LHCb. We show that while the total J/ψ cross-section is affected by uncertainties related to the charm mass, the t-distribution of differential cross-section offers a unique opportunity to unambiguously discriminate among saturation and non-saturation models. This is due to emergence of a pronounced dip (or multiple dips) in the t-distribution of diffractive photoproduction of vector mesons at relatively large |t| that can be traced back to the unitarity features of colour dipole amplitude in the saturation regime. We show that in saturation models the dip in the t-distribution recedes towards lower |t| with decreasing mass of the vector meson, increasing energy or decreasing Bjorken-x, and decreasing virtuality Q. We provide predictions for exclusive photoproduction of various vector mesons at the LHC and at future electron-proton colliders. This talk is mainly based on: arXiv:1402.4831.
Speaker: Amir Rezaeian (Universidad Tecnica Federico Santa Maria)
• 15:20
An ep collider based on proton-driven plasma wakefield acceleration 20m
Recent simulations have shown that a high-energy proton bunch can excite strong plasma wakefields and accelerate a bunch of electrons to the energy frontier in a single stage of acceleration. Using this scheme could lead to a future ep collider using the protons from the LHC and a compact electron accelerator up to an energy of 100 GeV with a length of about 170 metres. The parameters of such a collider are discussed as well as conceptual layouts within the CERN accelerator complex. The physics of plasma wakefield acceleration will also be introduced, with the AWAKE experiment, a proof of principle demonstration of proton-driven plasma wakefield acceleration, briefly reviewed, as well as the physics possibilities of such an ep collider.
Speaker: Matthew Wing (UCL)
• 15:40
Precision proton-proton and proton-nucleus collision studies at A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) 20m
We discuss the physics opportunities [1] which are offered by a next generation and multi-purpose fixed-target experiment exploiting the LHC beams. The multi-TeV LHC proton beam grants the most energetic fixed-target experiment ever performed, to study pp, pd and pA collisions at sqrt(s_NN) ~ 115 GeV. AFTER@LHC -- for A Fixed-Target ExperRiment -- gives access to new domains of particle and nuclear physics complementing that of collider experiments, in particular RHIC and the projects of electron-ion colliders. With a beam extracted by a bent crystal, the typical instantaneous luminosity achievable with AFTER@LHC in pp and pA mode [1] surpasses that of RHIC by more than 3 orders of magnitude and is comparable to that of the LHC collider mode, without pile-up thanks to the slow extraction mode. Another possibility is offered by the LCHb SMOG system, with a priori a limited luminosity, though. This provides a quarkonium, prompt photon and heavy-flavour observatory [1,2] in pp and pA collisions where, by instrumenting the target-rapidity region, gluon and heavy-quark distributions of the proton, the neutron and the nuclei can be accessed at large x and even at x larger than unity in the nuclear case. The nuclear target-species versatility provides a unique opportunity to study the nuclear matter versus the hot and dense matter formed in heavy-ion collisions. Modern detection technology should allow for the study of quarkonium excited states, in particular the chi(c) and chi(b) resonances thanks to the boost of the fixed-target mode. This would allow one to study gluon TMDs as suggested for instance in [3]. The fixed-target mode also has the advantage to allow for spin measurements with polarized targets, for instance single-spin asymmetries for Drell-Yan pair production [4]. We will review all these aspects and show first simulation results. References [1] S. J. Brodsky, F. Fleuret, C. Hadjidakis and J. P. Lansberg, Phys. Rept. 108 522 (2013) 239. [2] J. P. Lansberg, S. J. Brodsky, F. Fleuret and C. Hadjidakis, Few Body Syst. 53 (2012) 11-25 [3] D. Boer and C. Pisano, Phys. Rev. D 86 (2012) 094007 [4] T. Liu and B.Q. Ma, Eur. Phys. J. C 72 (2012) 2037
Speaker: Jean-Philippe Lansberg (IPN Orsay, Paris Sud U. / IN2P3-CNRS)
• 16:00
Coffee break 30m
• 16:30
The LHCb experiment is designed to perform high-precision measurements of CP violation and search for New Physics using the enormous flux of beauty and charmed hadrons produced at the LHC. The operation and the results obtained from the data collected do far demonstrate that the detector is robust and functioning very well. 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 published technical design reports.
Speaker: Tomasz Szumlak (AGH University of Science and Technology (PL))
• 16:50
Upgrading the ATLAS Tile Calorimeter electronics 20m
Speaker: Julio Vieira De Souza (Juiz de Fora Federal University (BR))
• 17:10
ATLAS Upgrades Towards the High Luminosity LHC: extending the discovery potential 20m
After successful LHC operation at the center-of-mass energy of 7 and 8 TeV in 2011 and 2012, plans are actively advancing for a series of upgrades, culminating roughly 10 years from now in the high luminosity LHC (HL-LHC) project, delivering of order five times the LHC nominal instantaneous luminosity along with luminosity levelling. The final goal is to extend the data set from about few hundred fb-1 expected for LHC running to 3000 fb-1 by around 2030. Current planning in ATLAS also has significant upgrades to the detector during the consolidation of the LHC to reach full LHC energy and further upgrades to accommodate running already beyond nominal luminosity this decade. The challenge of coping with HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for an all-new inner-tracker, significant upgrades in the calorimeter and muon systems, as well as improved triggers and data acquisition. This presentation summarises the various improvements to the ATLAS detector required to cope with the anticipated evolution of the LHC instantaneous luminosity during this decade and the next.
Speaker: Dr Diane Cinca (University of Glasgow (UK))
• 17:30
The NA62 experiment at CERN 20m
The NA62 Experiment at CERN aims to collect about 100 K->pinunu events in two years of data, keeping the background below 20%. The general physics program of the experiment and the prospects of the pinunu analysis in view of the first run scheduled for end 2014 will be reviewed.
Speaker: Karim Massri (University of Birmingham (GB))
• 17:50
Prospects for constrained supersymmetry at $\sqrt{s}=33$ TeV and $\sqrt{s}=100$ TeV proton-proton super-colliders 20m
Discussions are underway for a high-energy proton-proton collider. Two preliminary ideas are the $\sqrt{s}=33$ TeV HE-LHC and the $\sqrt{s}=100$ TeV VLHC. With Bayesian statistics, we calculate the probabilities that the LHC, HE-LHC and VLHC discover SUSY in the future, assuming that nature is described by the CMSSM and given the experimental data from the LHC, LUX and Planck. We find that the LHC with $300$/fb at $\sqrt{s}=14$ TeV has a $15$-$75\%$ probability of discovering SUSY. Should that run fail to discover SUSY, the probability of discovering SUSY with $3000$/fb is merely $1$-$10\%$. Were SUSY to remain undetected at the LHC, the HE-LHC would have a $35$-$85\%$ probability of discovering SUSY with $3000$/fb. The VLHC, on the other hand, ought to be definitive; the probability of it discovering SUSY, assuming that the CMSSM is the correct model, is $100\%$.
Speaker: Dr Andrew Fowlie (KBFI, Tallinn)
• 14:20 18:10
WG1: Structure Functions and Parton Densities C (BUW)

### C

#### BUW

Conveners: Karol Kovarik, Richard David Ball (Edinburgh University), Vladimir Chekelian (MPI fuer Physik)
• 14:20
HERAPDF1.5LO PDF Set with Experimental Uncertainties 25m
The HERAPDF1.5 PDF set, evolved in leading order (LO) $\alpha_s$ using DGLAP evolution equations, is presented. This LO PDF is particularly useful for Monte Carlo event generators, based on LO matrix elements plus parton showers.
Speaker: Amanda Sarkar (University of Oxford (GB))
• 14:45
HERAFitter - an open source QCD Fit platform 25m
The proton parton distribution functions (PDFs) are essential for precision physics at the LHC and other hadron colliders. Their current level of accuracy dominates the theory uncertainties in Higgs production and it affects substantially theory predictions for Beyond Standard Model high mass production. We would like to present the first stable release of the HERAFitter package - an open source project which provides a framework for QCD analyses in the context of multi-process and multi-experiment settings, bridging the state-of-the-art theory developments with an appropriate treatment of the precise experimental measurements. The HERAFitter program allows determination of the PDFs from the various measurements of the cross sections at $ep$, $p\bar{p}$ or $pp$ colliders. It includes various options for theoretical models and different choices to account for the experimental uncertainties. Therefore, this project represents not only an ideal environment for benchmarking studies, but also a support for the QCD interpretation of data analyses within the LHC experiments, as already demonstrated by several publicly available LHC results using the HERAFitter framework.
Speaker: Hayk Pirumov (Deutsches Elektronen-Synchrotron (DE))
• 15:10
Parton distribution functions at LO, NLO and NNLO with correlated uncertainties 25m
Sets of parton distribution functions of the proton are reported for the leading (LO), next-to-leading (NLO) and next-to-next-to leading order (NNLO) QCD calculations. The parton distribution functions are determined with the HERAFitter package using the HERA data and preserving correlations between uncertainties for the LO, NLO and NNLO sets. The sets are used to study uncertainties for ratios of cross sections calculated at different order in QCD.
Speaker: Mykhailo Lisovyi (Deutsches Elektronen-Synchrotron (DE))
• 15:35
Discussion of the color-dipole picture including final HERA results 25m
Based upon the color-dipole picture, simple closed analytic expressions for the longitudinal and the transverse photo-absorption cross sections at low values of the Bjorken variable of $x <0.1$ have been derived. The color-dipole picture, constrained by experimental data, including the final results from the H1 and ZEUS collaborations at HERA, as well as the recent results on the longitudinal structure function will be shown.
Speaker: Bernd Surrow (Temple University)
• 16:00
Coffee break 30m
• 16:30
Transverse momentum dependent gluon density from DIS precision data 25m
The combined measurements of proton’s structure functions in deeply inelastic scattering at the HERA collider provide high-precision data capable of constraining parton density functions over a wide range of the kinematic variables. We perform fits to these data using transverse momentum dependent QCD factorization and CCFM evolution. The results of the fits to precision measurements are used to make a determination of the nonperturbative transverse momentum dependent gluon density function, including experimental and theoretical uncertainties. We present an application of this density function to vector boson + jet production processes at the LHC.
Speaker: Hannes Jung (Deutsches Elektronen-Synchrotron (DE))
• 16:55
Impact parameter space and transverse distortion 25m
We investigate the spin flip Generalized Parton Distribution $E(x,0,t)$ in impact parameter space using the explicit light front wave functions (LFWFs) for the two-particle Fock state of the electron in QED. The Fourier transform (FT) of the GPDs by taking the longitudinal momentum transfer as zero ($\zeta=0$) gives the distribution of quarks in the transverse plane. We study the relationship of $E(x,0,t)$ with the distortion of unpolarized quark distribution in the transverse plane when the target nucleon is transversely polarized. We also determine the sign of distortion directly by taking FT of the transverse position coordinate.
Speaker: Dr Harleen Dahiya (Dr. B.R. Ambedkar National Institute of Technology)
• 17:20
TMD PDFs in the Laguerre polynomial basis 25m
We suggest a novel way of matching the non-perturbative part of TMD with the perturbative part aimed to increase the amount of perturbative information in the TMD PDF expression. For that we perform the OPE for the TMD PDF operator in the Laguerre polynomial basis. The choice of basis is dictated by the phenomenological observation that TMDs in the region of middle-$b_T$ has Gaussian behavior. The obtained perturbative expression for the TMD PDF is valid in the wide region of $b_T$ (we estimate this region as $b_T< 2-3$ GeV$^{-1}$ depending on $x$).
Speaker: Dr Alexey Vladimirov (Lund University)
• 17:45
Update on the CJ (CTEQ-Jefferson Lab) PDFs 25m
The CJ (CTEQ-Jefferson Lab) collaboration has developed next-to-leading order parton distribution functions (PDFs) determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed for the description of deep inelastic scattering data at large x and low Q^2, nuclear corrections for deuterium targets, and a functional form that accommodates a data-driven d/u ratio at the highest x values. The PDF sets correspond to three different models for the nuclear effects, and provide a more realistic uncertainty range for the d quark PDF compared with previous fits. Applications, for instance to weak boson production at colliders, have been investigated. Comparisons to Drell-Yan data will also be discussed.
Speaker: Alberto Accardi (Hampton U. and Jefferson Lab)
• Wednesday, 30 April
• 08:30 12:30
WG1: Structure Functions and Parton Densities B (BUW)

### B

#### BUW

Conveners: Karol Kovarik, Richard David Ball (Edinburgh University), Vladimir Chekelian (MPI fuer Physik)
• 08:30
Impact of ATLAS data on parton density functions 25m
Various measurements provided by the ATLAS collaboration have significant impact on parton density functions. The production of W and Z bosons inclusively or in association with charm-quark have are found to constraint the strange-quark density at medium and low Bjorken-x. Multi-Jet and photon production processes show impact on the gluon density. Off-resonance Drell Yan production at large lepton pair masses may be used to constrain anti-quark density at high x. A qualitative comparison of the ATLAS measurements to predictions based on different PDFs is presented.
Speaker: Paul Richard Newman (University of Birmingham (GB))
• 08:55
Measurement of the Neutral Current DY process with the ATLAS detector 25m
Neutral current Drell Yan cross section is sensitive to the parton distribution functions of the proton and electroweak corrections. The measurements for two distinct kinematic regions, below the Z boson mass peak and above are performed by the ATLAS collaboration using 7 TeV pp collision data. The results are compared to NNLO QCD predictions corrected for NLO EW effects calculated using various parameterizations of the parton distribution functions.
Speaker: Elena Yatsenko (Deutsches Elektronen-Synchrotron (DE))
• 09:20
Latest results on inclusive W/Z production at CMS 25m
At the LHC, inclusive production of W and Z bosons offer a unique window to perform stringent tests of theoretical predictions based on the Standard Model (SM) and probe its fundamental parameters. With the large samples of W and Z events collected with the CMS detector, many processes have been studied at an unprecedented precision. These measurements test the SM predictions up to next-to-next-to-leading order and provide valuable inputs to improve the theoretical framework used to model LHC physics. In this talk, recent CMS results on inclusive W/Z production are reviewed.
Speaker: Heiner Wollny (CERN)
• 09:45
AlphaS extraction and PDF constraints from jet measurements at CMS 25m
We present recent CMS results related to the extraction of the strong coupling constant and constraints on parton distribution functions. Results are based in recent jet measurements performed with 2011 data taken at center-of-mass energy of 7 TeV. Alpha_S extraction is based on measurements of multijet events and inclusive jet production cross sections, with the latest to be used also for setting constraints on the parton distribution functions.
Speaker: Georg Sieber (KIT - Karlsruhe Institute of Technology (DE))
• 10:10
Coffee break 50m
• 11:00
Measurements of the production of vector bosons in association with heavy flavour quarks at ATLAS. 25m
The production of heavy flavour quarks in association with a vector boson represents an important process to study QCD. High precision is achieved in measurements of differential cross sections and comparisons are made to state-of-the-art NLO QCD calculations and different parton distribution function parameterizations. Measurement of the production of a W boson in association with a charm quark using 4.6 fb-1 of pp collisions at sqrt(s) = 7 TeV with the ATLAS detector is reported. The measurement is performed using W boson plus tagged c-jet and W boson plus D/D* meson. Cross sections integrated over a fiducial kinematic range and differential as a function of the pseudorapidity of the lepton from the W-boson decay are reported.
Speaker: Georges Aad (CPPM, Aix-Marseille Université, CNRS/IN2P3 (FR))
• 11:25
Measurement of the muon charge asymmetry in inclusive W production at sqrt(s)=7 TeV with the CMS experiment at the LHC 25m
Measurements of the muon charge asymmetry in inclusive pp to W+X production at sqrt(s)=7 TeV are presented. The data sample corresponds to an integrated luminosity of 4.7 inverse femtobarns recorded with the CMS detector at the LHC. With a sample of more than twenty million W to mu nu events, the statistical precision is greatly improved in comparison to previous measurements. These new results provide additional constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable x from 10E-3 to 10E-1.
Speaker: Aleko Khukhunaishvili (University of Rochester (US))
• 11:50
Determination of strange quark distribution using recent CMS measurements on W production 25m
Associated W+charm production in proton-proton collisions at the LHC probes the strange quark in the proton at leading order. Recent CMS measurements of associated W+charm production and W muon charge asymmetry at 7 TeV are used together with HERA DIS data in a QCD analysis at next-to-leading order. The HERAFitter framework is used. The strange-quark fraction is determined as a function of the scaling variable x. Results are compared to measurements of ATLAS and NOMAD experiments.
Speaker: Ringaile Placakyte (Deutsches Elektronen-Synchrotron (DE))
• 08:30 12:30
WG2+WG4 Joint Session: Small-x, Diffraction and Vector Mesons + QCD and Hadronic Final States Auditorium (BUW)

### Auditorium

#### BUW

Conveners: Daniel Britzger (Deutsches Elektronen-Synchrotron (DE)), Konstantinos Kousouris (CERN), Lidia Maria Gorlich (Polish Academy of Sciences (PL)), Dr Mario Deile (CERN), Stephane Munier (Ecole polytechnique), Vladimir Braun (University of Regensburg)
• 08:30
Measurement of the Central Exclusive Production of pion pairs using tagged forward protons at the STAR detector at RHIC 20m
We shall present preliminary measurement of the Central Exclusive Production of the two oppositely charged pions produced in the process $pp->pXp$ , obtained with the STAR detector at RHIC at $\sqrt(s)$ = 200 GeV. The Roman Pots were used to tag forward protons while pion pair tracks were reconstructed in the STAR Time Projection Chamber (TPC). Spectra of the kinematical variables corrected for detector acceptance and efficiency are compared with predictions of models based on Regge phenomenology.
Speaker: Prof. Jacek Turnau (Institute of Nuclear Physics, PAN, Cracow)
• 08:50
Applications of the tensor pomeron model to exclusive central diffractive meson production 20m
We discuss exclusive central diffractive production of scalar ($f_{0}(980)$, $f_{0}(1370)$, $f_{0}(1500)$), pseudoscalar ($\eta$, $\eta'(958)$), and vector ($\rho^{0}$) mesons in proton-proton collisions. The amplitudes are formulated in terms of effective vertices required to respect standard rules of Quantum Field Theory and propagators for the exchanged pomeron and reggeons [1]. Different pomeron-pomeron-meson tensorial (vectorial) coupling structures are possible in general. In most cases two lowest orbital angular momentum - spin couplings are necessary to describe experimental differential distributions [2]. We discuss differences between results of the "tensorial pomeron" and "vectorial pomeron" models. For $f_{0}(980)$ and $\eta$ production reggeon-pomeron, pomeron-reggeon, and reggeon-reggeon exchanges are included in addition, which seems to be necessary at relatively low energies. The theoretical results are compared with the WA102 experimental data, in order to determine the model parameters. Correlations in azimuthal angle between outgoing protons, distributions in rapidities and transverse momenta of outgoing protons and mesons in a special "glueball filter variable", as well as some two-dimensional distributions are presented. For $\rho^{0}$ production photon-pomeron, pomeron-photon exchanges are considered. The coupling parameters of tensor pomeron and/or reggeon are fixed from the H1 and ZEUS experimental data of the $\gamma p \to \rho^{0} p$ reaction. We present first predictions of this mechanism for $pp \to pp \pi^{+} \pi^{-}$ reaction being studied at COMPASS, RHIC, Tevatron, and LHC [3]. Wy analyse influence of the experimental cuts on integrated cross section and various differential distributions for pions. We compare the $\rho^{0}$ contribution with double pomeron two-pion continuum [4]. We show that high-energy central production, in particular of pseudoscalar mesons, could provide crucial information on the spin structure of the soft pomeron. This is particularly clear for the coupling of the pomeron to particles carrying non-zeroth spin as $\rho^{0}$ meson for example. [1] C. Ewerz, M. Maniatis, and O. Nachtmann, \textit{A Model for Soft High-Energy Scattering: Tensor Pomeron and Vector Odderon}, Ann. Phys. \textbf{342} (2014) 31, arXiv:hep-ph/1309.3478. [2] P. Lebiedowicz, O. Nachtmann, and A. Szczurek, \textit{Exclusive central diffractive production of scalar and pseudoscalar mesons; tensorial vs. vectorial pomeron}, in print in Ann. Phys., arXiv:hep-ph/1309.3913. [3] P. Lebiedowicz, O. Nachtmann, and A. Szczurek, a paper in preparation. [4] P. Lebiedowicz, Ph.D. thesis, \textit{Exclusive reactions with light mesons: From low to high energies}, IFJ PAN Cracow, 2014.
Speaker: Piotr Lebiedowicz (Institute of Nuclear Physics PAN)
• 09:10
Studies of the underlying event with ATLAS 20m
Particle distributions sensitive to the underlying even have been measured with the ATLAS detector at the LHC. Charged particle multiplicity, charged and inclusive sum transverse momentum (pT) densities and mean charged-particle pT in the regions of each event, azimuthally transverse to the hardest jet, are also presented. When compared to the predictions of different Monte Carlo models, the data show sensitivity to the modelling of the underlying event.
Speaker: Andrei Minaenko (Institute for High Energy Physics (RU))
• 09:30
Measurement of the UE activity in pp collisions with the CMS detector 20m
A measurement of the underlying event activity is performed on proton-proton collisions, for different centre-of-mass energies, using the CMS detector. The charged particles in the azimuthal region transverse to the leading track and the leading track jet at central pseudorapidities are studied. The measurements are compared with various theoretical predictions. A significant increase in the average multiplicity and the scalar transverse momentum sum in the transverse region is observed up to transverse momenta of few GeV/c followed by a slower rate of increase. Both quantities are observed to increase at higher centre-of-mass energies. Files
Speaker: Mr Tomasz Maciej Frueboes (National Centre for Nuclear Research (PL))
• 09:50
UE event tunes and double parton scattering/Measurement of four-jet production in proton-proton collisions at sqrt(s) = 7 TeV; 30m
New UE event tunes, based on measurements done at 7 TeV as well as at lower energies together with Tevatron measurements are presented. Especially the energy dependent parameters of the UE are better constrained, allowing for extrapolation to 13-14 TeV. The new tunes are compared to measurements of Double Parton Scattering and the consistency of the tunes is investigated.
Speaker: Paolo Gunnellini (Deutsches Elektronen-Synchrotron (DE))
• 10:20
Coffee break 40m
• 11:00
Measurement of double-parton interactions in W+2 jets events with the CMS detector 20m
Double parton scattering is investigated in proton-proton collisions at sqrt(s) = 7 TeV where the final state includes a W boson, which decays into a muon and a neutrino, and two jets. The data sample corresponds to an integrated luminosity of 5 fb^(-1), collected with the CMS detector at the LHC. Observables sensitive to double parton scattering are investigated after being corrected for detector effects and selection efficiencies. The fraction of W+ 2-jet events due to double parton scattering is measured to be 0.055 +/- 0.002(stat.) +/- 0.014(syst.). The effective cross section, sigma_eff, characterizing the effective transverse area of hard partonic interactions in collisions between protons is measured to be 20.7 +/- 0.8(stat.) +/- 6.6(syst.)mb.
Speaker: Anastasia Grebenyuk (Universite Libre de Bruxelles (BE))
• 11:20
Production of dijets with large rapidity separation: Mueller-Navalet mechanism versus double-parton scattering 20m
We discuss production of four-jet final state in the $pp \rightarrow j j j j X$ reaction at the LHC through the mechanism of double-parton scattering (DPS) [1]. Each step of the DPS is calculated within the so-called factorized Ansatz in the LO collinear approximation. The LO pQCD calculations are shown to give a reasonably good descritption of the recent CMS and ATLAS data on inclusive jet production. Relative contribution of DPS is growing at large rapidity distance between jets. This is consistent with our experience from previous studies of double-parton scattering effects in the case of open and hidden charm production. The calculated differential cross sections as a function of rapidity distance between the most distant jets are compared with recent results of LL and NLL BFKL calculations for Mueller-Navalet (MN) jet production at $\sqrt{s} = 7$ TeV. The DPS contribution to the production of large rapidity distant jets is carefully studied also at the nominal LHC energy and in different jets transverse momenta range. The differential cross section as a function of dijet transverse momenta as well as two-dimmensional ($p^{min}_{T}\times p^{max}_{T}$)-plane correlations for the DPS mechanism are also presented. Some ideas how the DPS effects could be studied in the case of double dijet production are suggested. [1] R. Maciula and A. Szczurek, a paper in preparation.
Speaker: Rafal Maciula (Institute of Nuclear Physics PAN)
• 11:40
Confronting BFKL dynamics with experimental studies of Mueller-Navelet jets at the LHC 20m
The study of the production of two forward jets with a large interval of rapidity at hadron colliders was proposed by Mueller and Navelet as a possible test of the high energy dynamics of QCD. We analyze this process within a complete next-to-leading logarithm framework, supplemented by the use of the Brodsky-Lepage-Mackenzie procedure extended to the perturbative Regge dynamics, to find the optimal renormalization scale. This leads to a very good description of the recent CMS data at LHC for the azimuthal correlations of the jets.
Speaker: Mr Bertrand Ducloue
• 12:00
Beyond-DGLAP searches with Mueller-Navelet jets, and measurements of low-pT and forward jets at CMS 20m
We present searches for beyond-DGLAP resummation effects in production of dijets with large rapidity separation in pp collisions at sqrt{s}=7TeV. Ratios of inclusive over exclusive dijet production cross sections and dijet azimuthal decorrelations are presented as a function of rapidity separation between jets. Measurements are compared to predictions of conventional LO+PS MC generators as well as MC generators incorporating elements of the BFKL approach and analytic NLL BFKL calculations. The azimuthal correlation between forward and central jets is measured in proton–proton collisions at the LHC, at the centre-of-mass energy of 7 TeV. The forward jet is reconstructed in the hadronic forward (HF) calorimeter in the pseudorapidity region 3.2 < |η| < 4.7, while the central jet is limited to |η| < 2.8. At least one central jet and one forward jet are required to have transverse momentum of pT > 35 GeV. The azimuthal angle between the jets is measured for different separations in pseudorapidity, with the largest separation being ∆η = 7.5 units. The analysis is carried out for inclusive dijet events and for two subsamples, one where an additional jet is required between the forward and the central jet, and one where the additional jet is vetoed. Comparisons between data and several different Monte Carlo models and tunes show a large sensitivity to the modeling of QCD radiation. Measurements of the differential cross sections for the production of exactly four jets in proton-proton collisions are presented as a function of the transverse momentum pt and pseudorapidity eta, together with the correlations in azimuthal angle and the \pt balance among the jets. The data sample was collected in 2010 at a center-of-mass energy of 7 TeV with the CMS detector at the LHC, with an integrated luminosity of 36pb-1. The cross section for exactly 4 jets, with 2 hard jets of pt > 50 GeV each, together with 2 jets of pt > 20 GeV each, within |eta|< 4.7 is measured to be sigma = 330 +- 5 (stat) +- 45 (syst) nb. It is found that the addition of parton showers to fixed-order matrix element calculations describe the measured differential cross sections in only some regions of phase space and that including a contribution from double parton scattering in the models brings the predictions closer to the data.
Speaker: Grigory Safronov (ITEP Institute for Theoretical and Experimental Physics (RU))
• 08:30 12:30
WG3: Electroweak Physics and Beyond the Standard Model C (BUW)

### C

#### BUW

Conveners: Anna Kaczmarska (Polish Academy of Sciences (PL)), Krzysztof Turzynski (University of Warsaw), Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR)), Milada Muhlleitner (KIT - Karlsruhe Institute of Technology (DE))
• 08:30
Constraining supersymmetry using the relic density and the Higgs boson 20m
I will present the impact of the recent measurements of Planck, LHC experiments and Xenon100 in terms of constraints on supersymmetric parameters. I will consider two models: mSUGRA for an illustration, and a more general Minimal Supersymmetric Standard Model with 13 free parameters. The analysis is done with the SFitter tool allowing a comparison of Bayesian and profile likelihoods results. I will pin point how the allowed structures in the parameter spaces are driven by the combination of the dark matter annihilation mechanisms and the light Higgs mass predictions.
Speaker: Sophie Henrot-Versille (LAL)
• 08:50
Searches for electroweak production of supersymmetric gauginos and sleptons with the ATLAS detector 20m
Many supersymmetry models feature gauginos and also sleptons with masses less than a few hundred GeV. These can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents results from searches for gaugino and slepton pair production in final states with leptons.
Speaker: Ryo Nagai (Tokyo Institute of Technology (JP))
• 09:10
Search for electroweak SUSY production at CMS 20m
In this talk, the latest results from CMS on searches for supersymmetry produced through electroweak production channels are presented using 20/fb of data from the 8 TeV LHC run. A variety of complementary final state signatures and methods are used, such as searches with Higgs, W, and Z bosons in the final state, to probe gaugino and slepton production.
Speaker: Hamed Bakhshiansohi (School of Particles and Accelerator Inst. for Res. in Fundam. S)
• 09:30
Inclusive searches for squarks and gluinos with the ATLAS detector 20m
Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent ATLAS results on inclusive searches for supersymmetric squarks and gluinos in events containing jets, missing transverse momentum with and without light leptons, taus or photons.
Speaker: Thomas Gillam (University of Cambridge (GB))
• 09:50
Inclusive SUSY searches at CMS 20m
In this talk, the latest results from CMS on inclusive searches for squark and gluino production at the LHC are reviewed. A variety of complementary final state signatures and methods are presented using 20/fb of data from the 8 TeV LHC run.
Speaker: Dr Niki Saoulidou (University of Athens (GR))
• 10:10
Coffee break 20m
• 10:30
Squark pair production and decay at NLO matched with parton showers 20m
The pair production of squarks is one of the main search channels for supersymmetry at the LHC. For the interpretation of experimental data precise theoretical predictions are crucial. The work presented in the talk contributes to this effort by providing a fully differential calculation of the NLO SUSY-QCD corrections to the on-shell production of squark pairs supplemented by the decay of the squarks to the lightest neutralino and a quark in the MSSM. However, for precise simulations at the level of the actually measured experimental observables a combination of these fixed-order NLO calculations and parton showers is mandatory. To this end, the process was implemented in the Powheg-Box framework and interfaced with different parton shower programs. We study the impact of the NLO corrections on the differential scale dependence and K-factors and investigate the parton shower effects.
Speaker: Eva Popenda (Paul Scherrer Institut)
• 10:50
3rd generation SUSY searches at CMS 20m
In this talk, the latest results from CMS on searches for stop and sbottom squarks are presented. Searches for direct squark production and indirect production through gluino cascades in a variety of decay channels are reviewed. The results are based on 20/fb of data collected during the 8 TeV LHC run.
Speaker: Dr Alexis Kalogeropoulos (DESY)
• 11:10
Third generation SUSY searches with the ATLAS experiment 20m
Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Real and virtual production of third generation squarks via decay of a gluino can be significant if the mass of the gluino does not exceed the TeV scale. The talk presents recent ATLAS results from searches for gluino mediated stop and sbottom pair production.
Speaker: Steve Guy Muanza (Centre National de la Recherche Scientifique (FR))
• 11:30
Searches for supersymmetry in resonance production, R-parity violating signatures and events with long-lived particles at LHC 30m
An extended QCD sector beyond the minimal supersymmetric standard model or the admission of R-parity violation introduces new signatures to the search for supersymmetry at the LHC. Strongly interacting resonances may decay to jets, sleptons may decay via lepton-flavour violating processes and lightest supersymmetric particles may decay into many leptons with or without missing transverse momentum. Several supersymmetric models also predict massive long-lived supersymmetric particles. Such particles may be detected through abnormal specific energy loss, appearing or disappearing tracks, displaced vertices, long time-of-flight or late calorimetric energy deposits. The talk presents recent results from searches supersymmetry in resonance production, R-parity violating signatures and events with long-lived particles with ATLAS and CMS detectors.
Speaker: Dr Sofia Vallecorsa (Universite de Geneve (CH))
• 12:00
Higgs coupling measurements and impact on the MSSM 20m
The Run I of the LHC has not revealed any sign of new physics beyond the standard model (BSM). However, the discovery of a Higgs boson opens up new possibilities for probing various BSM scenarios with enlarged Higgs sectors and/or new particles affecting the loop-induced processes or opening new decay modes. I will present how we derive constraints on new physics from the Higgs searches performed by the ATLAS and CMS collaborations, taking (partly) into account the correlations between the experimental categories. This is used to determine the couplings of the Higgs boson, considering possible invisible/unseen decays. I will then show the impact of the Higgs measurements on the phenomenological MSSM and on the MSSM with a light neutralino dark matter. Finally, I will present a new, public tool for fitting the Higgs likelihood and deriving constraints on a broad class of new physics models. The experimental results are stored in a flexible XML database, and the model input can be specified in terms of reduced couplings, or cross sections and branching fractions, or signal strengths directly in a general and user-friendly way.
Speaker: Mr Beranger Dumont (LPSC Grenoble)
• 08:30 12:30
WG5: Heavy Flavours F (BUW)

### F

#### BUW

Conveners: Anze Zupanc (Jozef Stefan Institute), Martin Gorbahn (Liverpool University), Vanya Belyaev (ITEP Institute for Theoretical and Experimental Physics (RU))
• 08:30
Heavy-flavour production in pp, p-Pb and Pb-Pb collisions with ALICE at the LHC 25m
Heavy-flavour hadrons containing charm and beauty quarks are unique probes of the properties of the hot and dense QCD medium produced in heavy-ion collisions. Due to their large masses, heavy quarks are produced at the initial stage of the collision, almost exclusively via hard partonic scattering processes. Therefore, they are expected to experience the full collision history propagating through and interacting with the QCD medium. Such interaction modifies the phase-space distribution of heavy quarks in Pb-Pb collisions with respect to pp collisions. The measurement of this modification, referred as nuclear modification factor, is sensitive to the transport coefficients of the produced medium. A qualitative and quantitative understanding of the measurement of the nuclear modification factor requires reference measurements in pp and p-Pb collisions. Besides being the reference for Pb-Pb studies, pp heavy-flavour measurements constitute a powerful QCD test tool. The study of their production as a function of multiplicity of charged particles produced in the collision can give insights into multi-parton interaction phenomena. Finally the p-Pb reference measurement is important to disentangle hot medium effects from initial-state effects due to cold nuclear matter. The ALICE collaboration has measured the production of open heavy-flavour hadrons via their hadronic and semi-leptonic decays at mid-rapidity and in the semi-muonic decay channel at forward rapidity in pp, p-Pb and Pb-Pb collisions at 7, 5.02 and 2.76 TeV respectively. In this talk the latest experimental results are presented.
Speaker: Alessandro Grelli (University of Utrecht (NL))
• 08:55
Measurement of D* photoproduction at three different centre-of-mass energies at HERA 25m
The cross sections for the photoproduction of $D^\star$ mesons have been measured with the ZEUS detector at HERA at three different $ep$ centre-of-mass energies, $\sqrt{s}$, of 318, 251 and 225\,GeV. For each data set, $D^\star$ mesons were required to have a transverse momentum, $p_T^{D^\star}$, and pseudorapidity, $\eta^{D^\star}$, in the ranges, $1.9 < p_T^{D^\star} < 20$\,GeV and $|\eta^{D^\star}|<1.6$, respectively. The events were required to have a virtuality of the incoming photon, $Q^2$, of less than 1 GeV$^2$ and three different photon-proton centre-of-mass energies, corresponding to the same value of $y$, the fraction of the incoming electron momentum carried by the photon. The dependence on $\sqrt{s}$ was studied by normalising to the high-statistics measurement at $\sqrt{s} =318$ GeV. This led to the cancellation of a number of systematic effects both in data and in theory. Predictions from next-to-leading-order QCD describe well the energy dependence in data.
Speaker: Nataliia Zakharchuk (Deutsches Elektronen-Synchrotron (DE))
• 09:20
Combination of D* Differential Cross-Section Measurements in Deep Inelastic ep Scattering at HERA 25m
H1 and ZEUS have recently published differential cross sections for $D^\star$ production from their respective final data sets, for photon virtualities $Q^2 > 5$ GeV$^2$. These cross sections are combined at the visible cross section level, taking into account all relevant correlations. This significantly reduces the experimental uncertainties, while theory uncertainties from the combination procedure remain almost negligible. To extend the kinematic range down to $Q^2 > 1.5$ GeV$^2$, double differential cross sections are also combined with a subset of earlier $D^\star$ data. NLO QCD predictions are compared to the results.
Speaker: Mykhailo Lisovyi (Deutsches Elektronen-Synchrotron (DE))
• 09:45
Diffractive production of open charm and bottom at the LHC 25m
We discuss diffractive production of open charm and bottom mesons at the LHC [1]. The differential cross sections for single- and central-diffractive mechanisms for $c\bar c$ and $b\bar b$ pairs are calculated in the framework of the Ingelman-Schlein model corrected for absorption effects to include Regge factorization breaking observed at the Tevatron. In this approach one assumes that the pomeron has a well defined partonic structure, and that the hard process takes place in a pomeron-proton or proton-pomeron (single diffraction) or pomeron- pomeron (central diffraction) processes. Here, only the LO gluon-gluon fusion partonic subprocess is taken into consideration, which is calculated within simple collinear approximation. Both pomeron flux factors as well as parton distributions in the pomeron are taken from the H1 Collaboration analysis of diffractive structure function and diffractive dijets at HERA. The sub-leading corrections from reggeon type exchanges are explicitly calculated and also taken into consideration. Several quarks-level differential distributions are shown. The results are compared to the results of gluon disociation mechanism in the $k_t$-factorization approach [2] The hadronization of charm and bottom quarks is taken into account by means of fragmentation function technique. Predictions for single- and central-diffractive production in the case of inclusive $D$ and $B$ mesons, as well as $D\bar D$ correlations are presented, including detector acceptance of the ATLAS, CMS and LHCb Collaborations. The experimental aspects of possible standard and dedicated measurements are carefully discussed. [1] M. Luszczak, R. Maciula and A. Szczurek, a paper in preparation. [2] M. Luszczak, W. Schafer and A. Szczurek, Phys. Lett. B729 (2014)15.
Speaker: Marta Luszczak (University of Rzeszow)
• 10:10
Quarkonium production in pp, p-Pb and Pb-Pb collisions with the ALICE experiment at the LHC 25m
ALICE is the LHC experiment dedicated to the study of heavy ion collisions where extreme thermodynamical conditions are supposed to lead to the creation of a deconfined QCD state of matter called Quark-Gluon Plasma (QGP). Amongst the prominent probes of the QGP, heavy quarks are of special interest since they are produced in the initial parton-parton interactions of A-A collisions and interact with the medium throughout its evolution. In particular, the study of quarkonium (bound states of heavy quark anti- quark pairs) production is expected to provide essential information on QGP properties. Dissociation of quarkonia should occur in the medium and the dissociation rate for a given quarkonium state should depend on the medium temperature. A sequential suppression of the measured quarkonium yield should then be observed. However, several additional effects are to be taken into account in the interpretation of the results. Quarkonia can be regenerated in the medium and this effect should be much larger for charmonia (bound states of ccbar pairs) than for bottomonia (bound states of bbar pairs). In addition, Cold Nuclear Matter (CNM) effects (such as shadowing, anti-shadowing and break up or energy loss) must also be separated from effects due to the QGP formation. The CNM effects can be quantified by studying the quarkonium production in p-A collisions where the QGP is not expected to be created. Finally, quarkonium yield measurements in pp collisions provide stringent tests to hadroproduction models and benchmarks for p-A and A-A collision studies. In ALICE, the measurement of quarkonia can be performed with the forward spectrometer (−4 ≤ η ≤ −2.5) and the central barrel (−0.9 ≤ η ≤ 0.9) via the di-muonic and the di-electronic decay channel, respectively. Recent results on quarkonium production in pp, p-Pb and Pb-Pb collisions at the TeV scale will be reported.
Speaker: Loic Henri Antoine Manceau (Universita e INFN (IT))
• 10:35
Coffee break 30m
• 11:05
Charmonium production at HERA 25m
The exclusive deep inelastic electroproduction of $\psi(2S)\rightarrow \mu^+\mu^-$, $\psi(2S)\rightarrow J/\psi\pi^+\pi^-\rightarrow \mu^+\mu^-\pi^+\pi^-$ and $J/\psi\rightarrow \mu^+\mu^-$ have been studied with the ZEUS detector at HERA using an integrated luminosity of $354$ pb$^{-1}$. The analysis was carried out in the kinematic range $5 < Q^2 < 70$ GeV$^2$, $30 < W < 210$ GeV and $|t| < 1$ GeV$^2$, where $Q^2$ is the photon virtuality, $W$ the photon-proton centre-of-mass energy and $t$ the squared four-momentum transfer at the proton vertex. The cross-section ratio $\sigma_{\psi(2S)}/\sigma_{J/\psi}$ has been measured as a function of $Q^2$, $W$ and $t$.
Speaker: Nataliia Kovalchuk (Deutsches Elektronen-Synchrotron (DESY))
• 11:30
Running of the charm quark mass 25m
The combined HERA data on charm production in deep inelastic scattering have recently been used to determine the charm quark running mass $m_c(m_c)$ in the $\overline{\rm MS}$ renormalisation scheme. The same data are used differentially as a function of the photon virtuality $Q^2$ to evaluate the charm quark running mass at different physical scales to one-loop order. The scale dependence of the mass is found to be consistent with QCD expectations, and a graphical represention of the charm mass running, similar to the representation of the beauty mass running from LEP data, is obtained for the first time.
Speaker: Andrii Gizhko (Deutsches Elektronen-Synchrotron (DE))
• 11:55
Nuclear matter effects on J/$\psi$ production in Cu+Au and $U$+$U$ collisions in PHENIX 25m
The Phenix experiment at RHIC has produced high quality J/$\psi$ measurements in heavy ion interactions for various energies and collision systems. These measurements allow us to study the mechanisms which may modify the charmonium production in the nucleus. During 2012 run, the flexibility of the RHIC to provide collisions with different nuclei have led to the first experimental study of two new collision systems with unique initial collision geometries. The initial asymmetry of the Cu+Au system leads to differences in the J/$\psi$ suppression along the beam axis. The Phenix detector, with its extensive kinematic coverage, is well suited to measure the J/$\psi$ production in both forward and backward rapidities, −2.2$<$y$<$−1.2 and 1.2$<$y$<$2.2. Such studies, along with a comparison to the $d$+Au and Au+Au systems, provide insight into the interplay of cold and hot nuclear matter on the J/$\psi$ modification, and whether such effects could be factorized. The second system, $U$+$U$, extends further the maximum energy density reached in heavy ion collisions at RHIC and presents the possibility to study how this increase may alter the particle production. In this talk I will present results from Cu+Au and $U$+$U$ collision systems, focusing on the latest J/$\psi$ measurements from Phenix.
Speaker: Aneta Iordanova (University of California, Riverside)
• 08:30 12:30
WG6: Spin Physics D (BUW)

### D

#### BUW

Conveners: Barbara Pasquini (University of Pavia), Ernst Sichtermann (Lawrence Berkeley National Laboratory), Yann Bedfer (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 08:30
A_N in inclusive lepton-proton collisions 30m
Some estimates for the transverse Single Spin Asymmetry, $A_N$, in the inclusive processes $\ell \, p^{\uparrow} \to h \, X$ are compared with new experimental data. The predictions are based on the Sivers and Collins functions as extracted from SIDIS azimuthal asymmetries, within a transverse momentum dependent factorization approach. The values of $A_N$ thus obtained agree in sign and shape with the data.
Speaker: Dr Umberto D'Alesio (University of Cagliari and INFN, Italy)
• 09:00
Measurement of the Transverse Single-Spin Asymmetries for $\pi^{0}$ and Jet-like Events at Forward Rapidities at STAR in $p+p$ Collisions at $\sqrt{s}$ = 500 GeV 30m
Large transverse single-spin asymmetries ($A_N$) have been observed for forward inclusive hadron production in $p+p$ collisions at various experiments. In the collinear perturbative scattering picture, twist-3 multi-parton correlations can give rise to such an asymmetry. A transversely polarized quark can also give rise to a spin-dependent distribution of its hadron fragments via the higher twist equivalents of the Collins fragmentation function. The observed $A_N$ may involve contributions from both processes. These can be disentangled by studying asymmetries for jets, direct photons and jet-fragments. The STAR Forward Meson Spectrometer (FMS), a Pb-glass electromagnetic calorimeter covering the pseudo-rapidity ($\eta$) range 2.6-4.2 and full azimuth, can detect photons, neutral pions and eta mesons. We are measuring $A_N$ for $\pi^{0}$ and jet-like events reconstructed from photons in the FMS in $p+p$ collisions at $\sqrt{s}$ = 500 GeV that were recorded during the 2011 RHIC run. We study $A_N$ as a function of the number of observed photons in FMS, thereby exploring asymmetries for a range of event classes. We further study $A_N$ for forward jets and its dependency with forward-midrapidity jet correlation. The current status of the analysis will be discussed.
Speaker: Dr Mriganka Mouli Mondal (Texas A&M University)
• 09:30
Results on Transverse Spin Asymmetries in Polarized Proton - Proton Elastic Scattering at sqrt(s) = 200 GeV 20m
We present a preliminary result on a precision measurement of the transverse double spin asymmetries ANN and ASS in polarized proton-proton elastic scattering at sqrt(s) = 200 GeV in the small four momentum transferred (t) region 0.005 < -t < 0.035 (GeV/c)2, the Coulomb Nuclear Interference (CNI) region, which were obtained with the STAR experiment at RHIC. The result is based on about 20 million elastic events acquired in a run with dedicated optics. The preliminary values of ANN ≈ ASS = – 0.0051±0.0006(stat)±0.0010(sys), they are small but distinguishable from zero. We shall also present the result on the single transverse spin asymmetry AN obtained from the same sample of events. The result on AN can be explained by the interference of electromagnetic spin-flip and hadronic non-flip amplitude, so called CNI interference.
Speaker: Wlodek Guryn (BNL)
• 09:50
Gluon TMDs and Higgs boson production 20m
Recent activities on the determination of Transverse-Momentum Dependent Gluon Distributions (gluon TMDs) are reviewed. Several processes in lepton-proton and proton-proton collisions have been identified which give a clean access to gluon TMDS, in particular the back-to-back production of photon pairs, photon + Heavy Quarkonium pairs, ZZ-pairs, etc. It is also argued that gluon TMDs can be used as tools to determine the properties (such as the spin and the parity) of the newly found Higgs resonance at the LHC in the photon pair decay channel.
Speaker: Marc Schlegel (University of Tuebingen)
• 10:10
Di-hadron production at Jefferson Laboratory 20m
Semi-inclusive deep inelastic scattering (SIDIS) has been used extensively in recent years as an important testing ground for QCD. Studies so far have concentrated on better determination of parton distribution functions, distinguishing between the quark and antiquark contributions, and understanding the fragmentation of quarks into hadrons. Pair of hadrons (di-hadron) SIDIS provides information on the nucleon structure and hadronization dynamics that complements single-hadron SIDIS. The study of di-hadrons allow us to study higher twist distribution functions and Dihadron Fragmentation Functions (DiFF). Together with the twist-2 PDFs ($f_1$ , $g_1$ , $h_1$), the Higher Twist (HT) $e$ and $h_L$ functions are very interesting because they offer insights into the physics of the largely unexplored quark-gluon correlations which provide direct and unique insights into the dynamics inside hadrons . The CLAS spectrometer, installed in Hall-B at Jefferson Lab, has collected data using the CEBAF 6 GeV longitudinally polarized electron beam on longitudinally polarized solid NH3 targets. Preliminary results on beam-, target- and double-spin asymmetries will be presented.
Speaker: Dr Sergio Anefalos Pereira (INFN-Frascati)
• 10:30
Coffee break 30m
• 11:00
Precise spin-averaged and spin-dependent fragmentation function measurements at Belle 30m
Fragmentation functions (FFs) describe the formation of final state particles from a partonic initial state and are directly related to the intriguing QCD phenomenon of confinement. 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 Quantum Chromodynamics first principles and have to be extracted from experimental data. The Belle experiment at KEK, Japan, provides a large data sample for high precision measurements of unpolarized and polarized fragmentation functions. Here, the current status of the unpolarized and spin dependent FF measurements at Belle will be presented.
Speaker: Francesca Giordano (UIUC)
• 11:30
Quark fragmentation functions (FF) $D^h_q(z,Q^2)$ describe final-state hadronisation of quarks $q$ into hadrons $h$. The FFs can be extracted from hadron multiplicities produced in semi-inclusive deep inelastic scattering. The COMPASS collaboration has recently measured charged hadron multiplicities for identified pions and kaons using a 160\,GeV/c muon beam impinging on an isoscalar LiD target. The data cover a large kinematical range and provide an important input for global QCD analyses of world data at NLO, aiming at the determination of FFs. The newest results from COMPASS on pion multiplicities and pion fragmentation functions will be discussed. Supported by BMBF
Speaker: Mr Nicolas du Fresne von Hohenesche (Uni Mainz)
• 11:50
Phenomenology of unpolarized TMDs from Semi-Inclusive DIS data 20m
The analysis of experimental data on unpolarized Semi-Inclusive Deep-Inelastic Scattering (SIDIS) allows the extraction of information on the unpolarized transverse-momentum-dependent distribution functions (TMD PDFs) and fragmentation functions (TMD FFs). For the first time we investigate the flavor dependence of the partonic transverse momentum. Assuming Gaussian behavior in the transverse momentum plane, there are good indications for flavor dependence in the transverse momentum dependence of fragmentation functions, whereas the evidences are weaker for the distribution functions. We explore the impact of QCD evolution on the phenomenological description of SIDIS data, distinguishing the contributions to the evolution kernel related to intrinsic and perturbative transverse momentum.
Speaker: Mr Andrea Signori (VU University Amsterdam - Nikhef)
• 12:10
Unpolarized TMD extraction from HERMES and COMPASS SIDIS data 20m
We present results from our study of the unpolarized SIDIS cross sections. The analysis is based on the multiplicities of charged particles from HERMES and COMPASS experiments and of their corresponding azimuthal moments .
Speaker: J. Osvaldo Gonzalez H. (INFN Torino)
• 12:30 14:00
Lunch break 1h 30m BUW

#### BUW

• 14:00 18:05
WG1: Structure Functions and Parton Densities Auditorium (BUW)

### Auditorium

#### BUW

Conveners: Karol Kovarik, Richard David Ball (Edinburgh University), Vladimir Chekelian (MPI fuer Physik)
• 14:00
Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass 25m
The production of beauty and charm quarks in $ep$ interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared $5 < Q^2 < 1000$ GeV$^2$ using an integrated luminosity of 354 pb$^{-1}$. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of $Q^2$, Bjorken-$x$, jet transverse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double differential cross section as a function of $x$ and $Q^2$. The running beauty-quark mass is determined from a QCD fit at next-to-leading order to HERA data for the first time.
Speaker: Vladyslav Libov (Deutsches Elektronen-Synchrotron (DE))
• 14:25
Are b-PDFs (and b-fragmentation functions) needed at the LHC? 25m
Several key processes at the LHC in the standard model and beyond that involve bottom quarks, such as single-top, Higgs, and weak vector boson associated production, can be described in QCD either in a 4-flavor or 5-flavor scheme. In the former, b quarks appear only in the final state and are typically considered massive. In 5-flavor schemes, calculations include b quarks in the initial state, are simpler and allow the resummation of possibly large initial state logarithms of the type log(Q/mb) into the b parton distribution function (PDF), Q being the typical scale of the hard process. An analogous classification can be applied to processes involving bottom quarks in the final state, in which the b fragmentation acts like the b PDF. In this talk, I provide an explanation of why and how a substantial agreement between total cross sections can be obtained in the two schemes, as far as the initial state is concerned, and I present preliminary results for processes featuring heavy quarks in the final state.
Speaker: Dr Maria Ubiali (University of Cambridge)
• 14:50
Phenomenology of top-quark pair production at the LHC: studies with the DiffTop code 25m
We present phenomenological applications of DiffTop, a recently developed computer program for calculations of the differential cross section for top-quark pair production at hadron colliders. The code is based on an approximate next-to-next-to-leading order (NNLO) computation within the threshold resummation formalism in perturbative QCD. We compare the Difftop predictions with recent measurements at the LHC, in particular transverse momentum and rapidity distribution of the top quarks at a center-of-mass energy of 7 TeV and 8 TeV.
Speaker: Marco Guzzi (Deutsches Elektronen-Synchrotron (DE))
• 15:15
Generalization of the fastNLO approach to NNLO calculations 25m
Precision higher order calculations in perturbative QCD for hadron-hadron collisions often require large computing power and are time consuming, in particular in next-to-next-to-leading order (NNLO) accuracy and for non-inclusive or differential quantities. However, such computations are used frequently in modern phenomenological analyses like determinations of the strong coupling constant, $\alpha_s$, and the parton distribution functions (PDFs) of the proton. The fastNLO framework uses multi-dimensional interpolation techniques to factorize the convolutions of the perturbative coefficients with the PDFs and $\alpha_s$. The time-consuming part is only performed once and the results are stored in a flexible standardized format and can then subsequently be used for very fast calculations of the same quantity for arbitrary PDFs, $\alpha_s$, and for any choice of the renormalization and factorization scales. This talk focusses on recent develepments on the fastNLO framework and the generalization of the fastNLO approach to NNLO calculations. The fastNLO concept presented can be applied to any kind of process in high energy particle collisions and a new flexible computer code can easily be interfaced with any existing cross section calculation. As an example, we discuss the usage of recent differential cross section calculations for top-quark pair production in approximate NNLO in the fastNLO framework.
Speaker: Daniel Andreas Britzger (Deutsches Elektronen-Synchrotron (DE))
• 15:40
Variable flavor number scheme for final state jets 20m
We discuss a variable flavor number scheme for final state jets which can account for the effects of arbitrary finite quark masses for inclusive jet observables. The scheme is a generalization of the ACOT variable flavor number scheme with additional dynamical scales. It is based on a consistent description of massive collinear and soft modes allowing also for a treatment of rapidity divergences. We emphasize general properties, the calculations of threshold corrections, consistency conditions and relations to mass singularities found in fixed-order massive calculations. Specific examples covered are massive quark effects in event shapes and DIS.
Speaker: Mr Piotr Pietrulewicz (University of Vienna)
• 16:00
Coffee break 30m
• 16:30
Hessian PDF reweighting meets the Bayesian methods 25m
We discuss the Hessian PDF reweighting - a technique intended to estimate the effects that new measurements have on a set of PDFs. The method stems straightforwardly from considering new data in a usual $\chi^2$ fit and it naturally incorporates also non-zero values for the tolerance, $\Delta \chi^2 > 1$. In comparison to the contemporary Bayesian reweighting techniques, there is no need to generate large ensembles of PDF Monte-Carlo replicas, and the observables need to be evaluated only with the central and the error sets of the original PDFs. In spite of the apparently rather different methodologies, we show that the Hessian and the Bayesian techniques are actually one and the same, but only if the $\Delta \chi^2$ criterion is properly included to the Bayesian likelihood function that is a simple exponential. We illustrate the situation by considering a simplified example and the case of inclusive jets at the LHC.
Speaker: Dr Hannu Paukkunen (University of Jyväskylä)
• 16:55
The LHC p+Pb run from the nuclear PDF perspective 25m
The first p+Pb run at the LHC has opened a possibility to investigate the validity of the collinear factorization in a clearly higher energy scale than earlier in the nuclear collisions. Indeed, some processes that have been measured routinely in p+p($\overline {\rm p}$) collisions and utilized for years in free proton PDF fits, can now finally be reached also in the nuclear case. Such new data are expected to provide conclusive answers concerning the universality of the nuclear PDFs. In this talk, I will contrast some of the first, very recent p+Pb measurements to the predictions based on the nuclear PDFs, and discuss the insights and constraints these data offer. In particular, I will emphasize the inclusive (di)jet and $W^\pm$ production.
Speaker: Hannu Paukkunen (University of Jyväskylä)
• 17:20
The nCTEQ PDFs: LHC data and nuclear uncertainties 25m
A global analysis of the proton PDF requires a combination of DIS, DY, and jet data. The flavor differentiation depends heavily on the DIS data, all of which is measured on nuclear targets in neutrino scattering; hence the nuclear PDFs (nPDFs) come into play. Additionally, the LHC heavy ion runs with lead beams provide information in an entirely new kinematic regime; here, the W/Z production process is particularly enlightening. We study the compatibility of these data sets in a global nPDF analysis and extract the nuclear correction factors, and discuss the observed tensions between the nuclear correction factors in various data sets. We also quantify the nPDF uncertainty using a set of error PDF functions and show comparisons with recent nPDF determinations.
Speaker: Dr Aleksander Kusina (Southern Methodist University)
• 17:45
20 min. extra time 20m
• 14:00 18:20
WG2: Small-x, Diffraction and Vector Mesons B (BUW)

### B

#### BUW

Conveners: Lidia Maria Gorlich (Polish Academy of Sciences (PL)), Dr Mario Deile (CERN), Stephane Munier (Ecole polytechnique)
• 14:00
Forward jets and saturation effects within the high energy factorization 20m
We present results for forward jet production in p-p and p-Pb collisions at LHC within the High Energy Factorization (HEF) framework, obtained using new Monte Carlo programs. The HEF framework incorporates a convolution of unintegrated gluon densities and off-shell matrix elements. We briefly discuss both components: the relevant evolution equations and methods to obtain tree level off-shell matrix elements in a gauge invariant way. In particular, a new program capable to obtain the latter analytically for multiple off-shell legs is presented.
Speaker: Piotr Kotko
• 14:20
Forward-Central Jet Correlations 20m
The azimuthal correlation between forward and central jets is measured in proton–proton collisions at the LHC, at the centre-of-mass energy of 7 TeV. The forward jet is reconstructed in the hadronic forward (HF) calorimeter in the pseudorapidity region 3.2 < |η| < 4.7, while the central jet is limited to |η| < 2.8. At least one central jet and one forward jet are required to have transverse momentum of pT > 35 GeV. The azimuthal angle between the jets is measured for different separations in pseudorapidity, with the largest separation being ∆η = 7.5 units. The analysis is carried out for inclusive dijet events and for two subsamples, one where an additional jet is required between the forward and the central jet, and one where the additional jet is vetoed. Comparisons between data and several different Monte Carlo models and tunes show a large sensitivity to the modeling of QCD radiation.
Speaker: Pedro Miguel Ribeiro Cipriano (Deutsches Elektronen-Synchrotron (DE))
• 14:40
Measurement of Drell-Yan and associated jet cross section at low and high invariant masses 20m
Measurements of the differential Drell-Yan and associated jet cross section as a function of the Drell-Yan mass are presented using an integrated luminosity of 4.9 fb-1 in the dimuon channel of proton-proton collision data recorded with the CMS detector at the LHC at sqrt s =7 TeV. Cross sections as a function of the Drell-Yan transverse momentum are measured differentially in the Drell-Yan mass range of 30 to 1500 GeV. The pt spectrum of the Drell-Yan allows to study multiple-gluon emissions and resummation effects. The cross section for Drell-Yan production in association with one or two jets with pT > 30 GeV in the range | eta | < 4.5 are measured. Multi-jet emissions in a rapidity interval between the DY and the leading jet is a sensitive probe for multi-gloun emissions. The jet multiplicity in Drell-Yan production as a function of the rapidity separation of the leading jet and the Drell-Yan is presented. All measurements are compared to Monte Carlo predictions including matrix elements plus parton showers.
Speaker: Samantha Katherine Dooling (Deutsches Elektronen-Synchrotron (DE))
• 15:00
Leading track and leading jet cross sections at small transverse momenta 20m
The production yields of leading charged-particle jets and tracks in proton-proton collisions are measured at sqrt(s) = 8 TeV based with the CMS detector. The charged-particle jets (tracks) are measured in the pseudorapidity range |eta| < 1.9 (2.4) for transverse momenta pT > 1 (0.8)GeV. The yield distribution integrated over a given minimum transverse momentum pTmin, falls steeply with increasing pTmin, and provides information on the mechanism by which the underlying parton-parton cross sections are unitarized approaching the low-pT non-perturbative domain. Predictions obtained from various Monte Carlo event generators are compared to the measurements.
Speaker: Albert Knutsson (University of Antwerp (BE))
• 15:20
Nonlinear gluon evolution at atrong coupling 20m
The recent proposal for an evolution equation for unintegrated gluon densities for large values of the QCD coupling constant α¯s is going to be presented. The approach is based on the linear resummation model introduced by Sta\'{s}to. It is generalized to account for nonlinearity in the diffusive regime. The validity of the diffusive evolution at strong coupling is supported by the AdS/CFT consideration, as well as perturbative arguments. The solution of the proposed equation is presented as well as the generated saturation scale.
Speaker: Dr Krzysztof Kutak (IFJ PAN)
• 15:40
Small-x Scattering and Gauge/Gravity Duality 20m
We show how scattering at small-x can be studied by Pomeron exchange in AdS space using the gauge/gravity duality, with good results. In this approach the Pomeron at strong coupling is the graviton Regge trajectory. We use AdS space with a hard wall to mimic confinement effects. We use our results to fit HERA data, most recently for vector meson production, where both the proton and vector mesons are described by simple holographic wavefunctions in AdS. Our previous fits to deep inelastic scattering and deeply virtual Compton scattering data will also be briefly discussed.
Speaker: Marko Djuric
• 16:00
Coffee break 30m
• 16:30
Improving the kinematics for low-x QCD evolution equations in coordinate space 30m
High-energy evolution equations like BFKL, BK or JIMWLK are derived formally at infinite energy. In order to use those equations to resum leading logs in a physical observable at any finite energy in a consistent way, one needs to modifiy these equations by a kinematical constraint. I will discuss this issue in general, and show how to address the additional complications arising in position space, relevant for the BK and BFKL equations, and in the gluon saturation regime. This represent a further step towards gluon saturation phenomenology at NLO/NLL accuracy.
Speaker: Guillaume Beuf (University of Santiago de Compostela)
• 17:00
The next-to-leading order alpha_{s} corrections to JIMWLK 20m
The rapidity (energy) evolution of hadronic observables in scattering of a dilute perturbative projectile on a dense gluonic target is described in QCD by the JIMWLK equation. This is a functional non-linear equation that is consistent with the QCD unitarity. JIMWLK reduces to the linear BFKL equation when the scattering probability is low. I'll first sketch the way the leading order JIMWLK equation is derived and then discuss the alpha_{s}^{2} corrections. Partially based on hep-ph/1310.0378.
Speaker: Yair Mulian
• 17:20
Next-to-Eikonal corrections for gluon production in pA 20m
In the high energy limit, scattering processes can be described within the eikonal approximation, neglecting contributions which are power-suppressed at high energy. In the case of processes involving a large nuclear target, like pA or AA collisions, the Color Glass Condensate effective theory (CGC) is one of the most convenient formalisms based on the eikonal approximation. However, at LHC and RHIC energies, it is not known to what extent is the eikonal approximation reliable. We develop a method to expand systematically propagators in a strong background field, beyond the eikonal approximation. This allows one to calculate the power-suppressed corrections with respect to the CGC which are enhanced by the width of the target. As a first example, we calculate such next-to-eikonal power-suppressed corrections for central gluon production in pA collisions. In that context, the first corrections (linear in the width of the target) vanish for the unpolarized cross-section, making the CGC more reliable than expected, but dominate in the case of some single-transverse-spin asymmetries.
Speaker: Tolga Altinoluk (Universidade de Santiago de Compostela)
• 17:40
On effects of multiple gluons in J/psi hadroproduction 20m
Prompt J/psi hadroduction is analyzed beyond the leading twist two-gluon production mechanism. A contribution to the process is sudied in detail in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This contribution enters at non-leading twist, but is enhanced at large energies due to large double gluon density at small x. The three-gluon contribution to prompt J/psi production is calculated within perturbative QCD, in the k_T factorisation framework, and it is found to provide a significant correction to the standard leading twist cross-section at the energies of the Tevatron or the LHC. The results are given as differential pT-dependent cross-sections for J/psi polarisation components.
Speaker: Dr Leszek Motyka (Jagiellonian University)
• 18:00
Heavy quark impact factor 20m
We present the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic accuracy in a form suitable for phenomenological studies at the LHC within the $k_T$-factorization scheme as described in the publication JHEP 1312 (2013) 066.
Speaker: Michal Deak (Universidade de Santiago de Compostela)
• 14:00 18:05
WG3: Electroweak Physics and Beyond the Standard Model C (BUW)

### C

#### BUW

Conveners: Anna Kaczmarska (Polish Academy of Sciences (PL)), Krzysztof Turzynski (University of Warsaw), Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR)), Milada Muhlleitner (KIT - Karlsruhe Institute of Technology (DE))
• 14:00
Higgs spin and CP properties at the LHC 20m
The Higgs spin and CP properties can be tested at the LHC looking at differential distributions (angular correlations, invariant mass and momentum distributions) and also total rates. We will discuss how to combine these sources of information and how they relate to known models.
Speaker: Veronica Sanz Gonzalez
• 14:20
Higgs couplings and properties with ATLAS 20m
A detailed review of the latest results on the main properties of the Higgs boson in the diphoton, ZZ (with subsequent decays to four leptons), WW (with subsequent decays to lvlv) and Z? channels, with the ATLAS detector using approximately 25 fb-1 of pp collision data collected at 7 TeV and 8 TeV in 2011 and 2012, will be given. The measurements discussed will be the mass, couplings properties and main quantum numbers in these channels through various production processes.
Speaker: Nicola Venturi (University of Toronto (CA))
• 14:40
Higgs boson couplings and properties with CMS 20m
Many different production and decay modes of the 126 GeV mass Higgs boson have been studied by the CMS collaboration at the LHC collider. The analysis is based on pp collision data collected at centre-of-mass energies of 7 and 8 TeV corresponding to integrated luminosities of 5/fb and 20/fb respectively. The measurement of the Higgs boson couplings and of the study of its properties are presented.
Speaker: Linda Finco (Universita e INFN (IT))
• 15:00
Search for the Higgs boson in fermionic channels using the ATLAS detector 20m
Since the discovery of the Higgs boson by the ATLAS and CMS experiments at the LHC, the emphasis has shifted towards measurements of its properties. Of particular importance is the direct observation of the coupling of the Higgs boson to fermions. In this presentation a comprehensive review of ATLAS results in the search for the Higgs boson in tau, muon, and b-quark pairs will be given.
Speaker: Claire Lee (University of Johannesburg (ZA)/ Academia Sinica (TW))
• 15:20
Search for the Higgs boson in fermionic channels using the CMS detector 20m
Searches for the Higgs boson have been carried out in different fermionic decay modes with the CMS detector at the LHC collider. The analysis is based on pp collision data collected at centre-of-mass energies of 7 and 8 TeV corresponding to integrated luminosities of 5/fb and 20/fb respectively. The strategy and results of the searches are reported.
Speaker: Jesus Manuel Vizan Garcia (Universite Catholique de Louvain (UCL) (BE))
• 15:40
Search for Standard Model ZH->llbb at D0 20m
We present an improved measurement for the standard model Higgs boson production in association with a Z boson, using 9.7 fb-1 of ppbar collision data collected by the D0 detector at sqrt(S) = 1.96 TeV. Events are selected with two electrons or two muons that are consistent with the decay of a Z candidate, and at least two reconstructed jets including at least one b-tagged jet). We use improved algorithms for lepton reconstruction and use new optimization to determine the b-tagging operating points. Four dedicated random forests of decision trees (RFs) are trained in order to distinguish the signal from ttbar, Z+Heavy Flavor jets, Z+Light Flavor jets and diboson background events respectively. The final discriminant is trained separately in five regions according to the output of the RFs. We measure the ZH production cross-section times Higgs branching ratio to two b-jets with improved sensitivity.
Speaker: Mr Peng Jiang (University of Science and Technology of China)
• 16:00
Coffee break 20m
• 16:20
A theoretical review of triple Higgs coupling studies at the LHC 20m
After the discovery of a Higgs boson at the LHC, the next important step is to measure its couplings to fermions and boson to unravel its true nature, in particular to look for effects beyond the Standard Model (SM). In order to ultimately test the shape of the scalar potential that triggers the electroweak symmetry breaking, it is crucial to measure the trilinear Higgs coupling at the LHC. This talk will present the theoretical status of the SM Higgs pair production mechanisms that are needed for such a measurement and some preliminary studies for a high luminosity LHC.
Speaker: Dr Julien Baglio (Karlsruhe Institute of Technology)
• 16:40
Higgs Pair Production via Vector Boson Fusion at the LHC 20m
The measurement of Higgs pair production will be one of the cornerstones of the LHC physics program in the coming years, with the upcoming of the high-energy and high-luminosity phase. The Vector Boson Fusion (VBF) production channel probes directly the coupling of new physics and of Higgs to gauge bosons, in addition to reducing background contribution. In the VBF channel, the production of Higgs pairs is sensitive to the strong interactions of a composite Higgs boson, and would allow a direct extraction of the hhVV quartic coupling. Other anomalous couplings of the Higgs to itself or to vector bosons would also lead to modified production rate and kinematics. In addition, the production via VBF of an heavy object on-shell, subsequently decaying to a Higgs boson pair, may occur: the case of a kk-graviton from warped extra dimension models will be taken as a benchmark.
Speaker: Andrea Massironi (Northeastern University (US))
• 17:00
Searches for BSM Higgs bosons with CMS 20m
Many searches for BSM Higgs bosons have been carried out with the CMS detector at LHC. The analysis is based on pp collision data collected at centre-of-mass energies of 7 and 8 TeV corresponding to integrated luminosities of 5/fb and 20/fb respectively. Several different extensions of the Standard Model are considered such as 2HDM, MSSM, NMSSM and so on. No evidence of BSM Higgs bosons, in addition to the discovered SM-like 126 GeV Higgs boson, has been found and exclusion limits in the different models have been derived
Speaker: Tristan Arnoldus Du Pree (Universite Catholique de Louvain (UCL) (BE))
• 17:20
Beyond-the-Standard Model Higgs Physics using the ATLAS Experiment 20m
The discovery of a Higgs boson with a mass of about 125 GeV has prompted the question of whether or not this particle is part of a larger and more complex Higgs sector than that envisioned in the Standard Model. In this talk, the current results from the ATLAS Experiment on Beyond-the-Standard Model (BSM) Higgs searches are outlined. Searches for additional Higgs bosons are presented and interpreted in well-motivated BSM Higgs frameworks, such as two-Higgs-doublet Models and the Minimal and Next to Minimal Supersymmetric Standard Model.
Speaker: Dmitri Sidorov (Oklahoma State University (US))
• 17:40
2HDMs after the LHC's 8 TeV run 20m
Almost all data collected at the LHC during the 7 and 8 TeV runs has now been analysed by the ATLAS and CMS collaborations. Consistency with the Standard Model (SM) predictions has cornered two-Higgs double models (2HDMs) into SM-like corners of the parameter space. We will discuss the status of several types of two-Higgs doublet focusing on the possibilities of probing the still allowed parameter space for the different types of models.
Speaker: Rui Santos (ISEL)
• 18:00
5 min. extra time 5m
• 14:00 18:30
WG5: Heavy Flavours F (BUW)

### F

#### BUW

Conveners: Anze Zupanc (Jozef Stefan Institute), Martin Gorbahn (Liverpool University), Vanya Belyaev (ITEP Institute for Theoretical and Experimental Physics (RU))
• 14:00
Theory overview of $B_{s,d} \to \mu^+ \mu^-$ decays 24m
I will give a theoretical overview of the rare decays $B_{s,d} \to \mu^+ \mu^-$, which have long been promising probes of New Physics. Notably there has been important progress in predicting the branching ratios for these decays in the Standard Model, which I will present. This progress is timely in light of recent experimental measurements of these branching ratios, and I will discuss the implications of these measurements for New Physics. Furthermore, I will highlight the utility of the time-dependent observables of these decays, particularly the effective lifetime of $B_s \to \mu^+ \mu^-$, which complement the branching ratio observable in the search for New Physics.
Speaker: Rob Knegjens (T)
• 14:24
Perturbative contributions to rare B-meson decays 24m
Loop-mediated rare B-meson decays provide sensitive tests of the Standard Model and constraints on its extensions. I will present a brief review of several recent perturbative calculations that contribute to precise theoretical predictions for $B_{s,d} \to \ell^+ \ell^-$, $B \to X_s \gamma$ and $B \to X_s \ell^+ \ell^-$.
Speaker: Mikolaj Krzysztof Misiak (University of Warsaw (PL))
• 14:48
Rare Decays at LHCb 24m
LHCb has a vast programme of searches for new physics in rare decays of B and D mesons. Recent highlights are presented, inclusing intruiging results from the decays B->K*mumu and B->Kpipigamma. We also report about the observation of a resonance in the decay B+ -> K+ mu+ mu- at low recoil.
Speaker: Jaroslaw Pawel Wiechczynski (Polish Academy of Sciences (PL))
• 15:12
Electroweak and radiative penguin processes in B decays at Belle 24m
Electroweak and radiative penguin processes such as the quark-level b -> s l+ l- and b -> s gamma decays occur only through the FCNC loop or box diagrams in the Standard Model (SM) and so provide a very powerful probe to look for new physics beyond the SM. In this talk, we present recent results from Belle on these decays. For the first time, we measure the forward-backward asymmetry of inclusive B -> Xs l+ l- decays, where Xs is the hadronic recoil system containing a strange quark, using the full \Upsilon(4S) event sample of 711 fb^-1 produced by the KEKB collider and collected by the Belle detector. We also report new results on the search for radiative B -> p \bar{p} Lambda gamma decays.
Speaker: Luis PESANTEZ
• 15:36
Radiative B decays and new physics searches at BABAR 24m
We present recent results obtained with the full data set of about 470 millions B meson pairs recorded by the BABAR experiment at the PEP-II e+e- storage ring. In particular we report on studies of B-meson decays via radiative or electroweak penguins. Sensitivity to New Physics is tested through measurements of decay rates, rate asymmetries, and CP asymmetries, in several B -> Xs gamma and B -> Xs l+l- processes.
Speaker: Liang Sun (University of Cincinnati (US))
• 16:00
Coffee break 30m
• 16:30
Study of rare and suppressed processes in B meson decays with ATLAS 24m
The large amount of Heavy Flavor data collected by the ATLAS experiment is potentially sensitive to New Physics, which could be evident in processes that are naturally suppressed in the Standard Model. The most recent results on the search for the rare decay Bs (B0) -> mu+mu- are presented. Recent results are also presented on the angular distribution parameters AFB and FL describing the decay Bd -> K*mu+mu- -> K+pi-mu+mu-. The accuracy obtained from data collected in 2011 is comparable to the best previous measurement in the region q^2(mu+mu-)>16 GeV^2.
Speaker: Vladimir Nikolaenko (Institute for High Energy Physics (RU))
• 16:54
Comprehensive Bayesian Analysis of Rare (Semi)leptonic and Radiative B Decays 24m
We analyse the degree to which the experimental data on $b\to s\gamma$ and $b\to s\ell^+\ell^-$ decays can be described within the Standard Model, and several extensions. Besides deriving constraints on the $|\Delta B| = |\Delta S| = 1$ Wilson coefficients, we also fit for hadronic parameters in a Bayesian analysis. Results will be shown for fits to data on $B\to \lbrace X_s, K^\ast\rbrace\gamma$, $B_s \to \ell^+\ell^-$ and $B\to \lbrace X_s, K, K^\ast\rbrace \ell^+\ell^-$ decays.
Speaker: Dr Danny van Dyk (Siegen University)
• 17:18
Space for New Physics in Neutral B mixing observables 24m
The talk will provide a general overview of the physics associated with neutral B meson oscillations, in particular on how the study of the mixing observables allows to constrain the space available for new physics. Special emphasis will be given to the decay rate difference $\Delta \Gamma_d$ of the $B_d$ sector. According to recent model independent studies of new tree-level contributions and/or a violation of the CKM unitarity this observable can be enhanced by a factor of up to 4 with respect to its Standard Model value without getting in contradiction with current experimental data. The implications of this result in connection with the recent discrepancy for the like-sign dimuon asymmetry and possible new sources of CP violation will be discussed.
Speaker: Mr Gilberto Tetlalmatzi-Xolocotzi (IPPP Durham)
• 17:42
LHCb has performed many word-best mass and lifetime measurements of baryons and mesons containing b and c quarks.
Speaker: Paul Sail (University of Glasgow (GB))
• 18:06
Study of the Lambda$_b$ decay properties with the ATLAS experiment 24m
The ATLAS detector at the LHC is collecting - among others - a large statistics of Lambda_b decays, allowing the study of production and decay properties of this b-flavored hadron. This statistics is what allowed one of the most precise measurements of the Lambda_b lifetime. We will review ATLAS' latest results on the decay properties of this baryon, including the measurement of the parity violating asymmetry parameter alpha_b in Lambda_b -> Lambda J/psi, obtained from the study of angular correlations in the p pi- mu+ mu- final state. The measurement is compared to predictions based on perturbative QCD and heavy quarks effective theory.
Speaker: Tatjana Agatonovic-Jovin (University of Belgrade (RS))
• 14:00 18:30
WG6: Spin Physics D (BUW)

### D

#### BUW

Conveners: Barbara Pasquini (University of Pavia), Ernst Sichtermann (Lawrence Berkeley National Laboratory), Yann Bedfer (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 14:00
Deeply Virtual Compton Scattering to the twist-four accuracy: Impact of finite-t and target mass corrections 25m
We carry out the first complete calculation of kinematic power corrections $\sim t/Q^2$ and $\sim m^2/Q^2$ to several key observables in Deeply Virtual Compton Scattering. The issue of convention dependence of the leading twist approximation is discussed in detail. In addition we work out representations for the higher twist corrections in terms of double distributions, Mellin-Barnes integrals and also within a dissipative framework. This study removes an important source of uncertainties in the QCD predictions for intermediate photon virtualities $Q^2\sim 1$-$5\,\text{GeV}^2$ that are accessible in the existing and planned experiments. In particular the finite-t corrections are significant and must be taken into account in the data analysis.
Speaker: Vladimir Braun (University of Regensburg)
• 14:25
Crossed channel analysis of quark and gluon generalized parton distributions with helicity flip 25m
Quark and gluon helicity flip generalized parton distributions (GPDs) are seen to be a convenient tool to address the transversity quark and gluon structure of the nucleon. In order to construct a theoretically consistent parametrization of these hadronic matrix elements, we work out the set of combinations of those GPDs suitable for the SO(3) partial wave (PW) expansion in the cross-channel. This universal result will help to build up a flexible parametrization of these important hadronic non-perturbative quantities. We also discuss the possible phenomenological applications.
Speaker: Dr Kirill Semenov-Tian-Shansky (University of Liege)
• 14:50
A classification of chiral-odd pion generalized parton distributions beyond leading twist 25m
We define in a systematic way, based on the light-cone collinear factorization method, the chiral-odd generalized parton distributions (GPDs) of a pseudoscalar hadron (such as the $\pi^0$) up to twist 6. For that, we introduce the relevant matrix elements for 2-parton non-local operators, as well as matrix elements for 3-parton non-local correlators. Their detailed parametrization is fixed based on parity, charge conjugation and time reversal invariance. The reduction of these GPDs to a minimal set is performed by the use of constraints provided by QCD equations of motion and rotation on the light-cone.
Speaker: Samuel Wallon
• 15:15
Transverse densities in the nucleon's chiral periphery 25m
Transverse densities describe the nucleon's spatial structure in the parton picture and correspond to a projection of the GPDs in the impact parameter representation. We use chiral effective field theory to calculate the transverse charge and current densities in the nucleon's chiral periphery (transverse distances b ~ 1/m_pi) and study their properties [1]. The peripheral densities are expressed in terms of the light-cone wave function of the chiral pion-nucleon system, calculable directly from the chiral Lagrangian. A simple mechanical interpretation of the peripheral densities is obtained in terms of the (classical) orbital angular momentum structure of the system. We also extend these studies to the peripheral transverse densities of matter and momentum, related to the energy-momentum tensor form factors, and verify their relation to moments of peripheral GPDs. [1] C. Granados, C. Weiss, JHEP 1401 (2014) 092
• 15:40
DVCS measurements at HERMES 25m
Deeply Virtual Compton Scattering is currently one of the most promising processes that provides information about the structure of the nucleon in the framework of Generalized Parton Distributions. During its last years the Deeply Virtual Compton Scattering process was extensively studied at HERMES experiment through measurement of cross section asymmetries. To the virtue of unique experimental conditions, HERMES had collected a wealth of data on scattering a longitudinally polarized lepton (electron/positron) beam off unpolarized, longitudinally and transversely polarized hydrogen targets, as well as off unpolarized and longitudinally polarized deuterium targets. During the past two years of HERA operation a recoil detector around the target area allowed for the full kinematic reconstruction of the exclusive DVCS event, leading to a clean measurement of the beam-helicity asymmetry with background well below the 1% level. The recoil detector also allowed for first measurement of the related process of associated DVCS, in which the proton is excited to a Delta resonance, giving access to transition GPDs. In this talk these recent results using the recoil detector will be presented.
Speaker: Klaus Rith (University of Eralngen-Nürnberg)
• 16:05
Coffee Break 25m
• 16:30
The $g_2$ Spin Structure Function 30m
Jefferson Lab has been at the forefront of a program to study the polarized structure of nucleons. Measurements of the spin-dependent structure functions, $g_1$ and $g_2$, have proven to be powerful tools in testing and understanding Quantum Chromodynamics. To measure $g_2$ a transversely polarized target is needed, which proves to be challenging experimentally. Prior to JLab, the only dedicated experiment to measure $g_2$ was SLAC E155x, which shows consistency with the leading twist $g_2^{WW}$ prediction, but has large uncertainties. The function $g_2^n$ has been measured extensively in Hall A at JLab over a wide range of $Q^2$. The Resonances Spin Structure (RSS) experiment in Hall C gave a precision measurement of $g_2$ for the proton and deuteron at intermediate $Q^2$, providing the first world data for $g_2^{p,d}$ in the nucleon resonance region. The Spin Asymmetries of the Nucleon experiment (SANE), also performed in Hall C, provided a measurement of $g_2$ in the high $Q^2$ (DIS) region. More recently, the $g_2^p$ experiment took data covering the low $Q^2$ region. The 0$^{th}$ moment of $g_2$ provides a test of the Burkhardt-Cottingham sum rule, which states that the integral of $g_2$ over the Bjorken scaling variable x goes to zero. This sum rule, valid for all values of $Q^2$, has been satisfied for the neutron, but a violation is suggested for the proton at high $Q^2$. The 2$^{nd}$ moment allows for a benchmark test of lattice QCD predictions at high $Q^2$ with $d_2$, and a test of Chiral Pertubation Theory at low $Q^2$. Specifically, the behavior of the longitudinally-transverse spin polarizability ($\delta_{LT}$), as $\chi$PT calculations of this quantity deviate significantly from the measured neutron data. This talk will provide an overview of the JLab effort to measure $g_2$, with a focus on the more recent $g_2^p$ experiment; the current status of the analysis will be discussed along with preliminary results.
Speaker: Ms Melissa Cummings (College of William and Mary)
• 17:00
Single and double polarization asymmetries from deeply virtual exclusive $\pi^0$ electroproduction 30m
The target and double spin asymmetry measurements of exclusive $\pi^0$ electroproduction were performed for the first time in DIS region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS) and longitudinally polarized proton target. The wide kinematic coverage and good resolution of CLAS allowed measurements in full azimuthal range providing an opportunity to extract single and double spin asymmetries proportional to polarized structure functions. Their angular dependences in hadronic center-of-mass system were analyzed, and extracted moments are compared to recent theoretical handbag-based calculations based on chiral-even and chiral-odd GPDs contributions. The interpretation of present results within the framework of the modified perturbative approach and their use as a constraint for models of the $t$ behavior will be discussed.
Speaker: Andrey Kim (University of Connecticut)
• 17:30
New JLab/Hall A Deeply Virtual Compton Scattering results 30m
Due to new information obtained during the 2010 DVCS experiment in JLab/Hall A, we have performed a re-analysis of the 2004 JLab/Hall A E00-110 DVCS experiment. In addition to the extraction of helicity-dependent and unpolarized cross sections at fixed $x_B=0.36$ for three different $Q^2$ (as the original analysis), we have used the same data set to extract the same quantities at fixed $Q^2$=2.1 GeV$^2$ for two different $x_B$ values. The phenomenological implications of this updated data set will be discussed. Finally, some preliminary results from the 2010 proton data set will be shown as well.
Speaker: Franck Sabatié (CEA Saclay)
• 18:00
Exclusive meson production at COMPASS 30m
Hard exclusive leptoproduction of mesons on nucleons has played an important role in studies of the hadron structure and recently gained renewed interest as it allows access to generalised parton distributions (GPDs). GPDs provide a novel and comprehensive description of the partonic structure of the nucleon and contain a wealth of new information. For instance GPDs give a description of the nucleon as an extended object, referred to as 3-dimensional nucleon tomography, and give access to the orbital angular momentum of quarks. Exclusive meson production is sensitive to various types of GPDs for different flavours depending on the quark content and the quantum numbers of the meson ($\rho^0$, $\phi$, $\pi^{0}$, ...). In this talk we will summarize recent measurements of exclusive vector meson production performed by the COMPASS Collaboration. In particular, recent results on single-spin and double-spin asymmetries for exclusive $\rho^0$ and $\omega$ production measured on the transversely polarized proton target will be presented. Some of these asymmetries are sensitive to the GPDs $E$, which are related to the orbital angular momentum of quarks. Other asymmetries are sensitive to the chiral-odd, transverse GPDs $H_{T}$. Our results provide the first experimental evidence from the hard exclusive vector meson production for the existence of non-vanishing GPDs $H_{T}$.
Speaker: Pawel Sznajder (National Centre for Nuclear Research (PL))
• 14:00 18:20
WG7: Future experiments E (BUW)

### E

#### BUW

Conveners: Abhay Deshpande (Stony Brook University), Alexei Prokudin (Jefferson Lab), Alice Valkarova (Charles University (CZ))
• 14:00
eRHIC: An Electron - Ion Collider at BNL 20m
BNL’s plan for an electron-ion collider, eRHIC, a major new research tool that builds on the existing RHIC facility to advance the long-term vision for Nuclear Physics to discover and understand the emergent phenomena of Quantum Chromodynamics (QCD) will be presented. The scientific requirements for such a facility, following up on the community-wide 2012 white paper, “Electron-Ion Collider: the Next QCD Frontier” [arXiv:1212.1701], and the design concept that incorporates new, innovative accelerator techniques to provide a cost-effective upgrade of RHIC with polarized electron beams colliding with the full array of RHIC hadron beams, 250 GeV polarized protons and 100 GeV/u heavy ion beams, at a luminosity of 10^33 cm^-2 s^-1 will be shown. Further the IR design together with the studies for an eRHIC detector realization, based on the sPHENIX and STAR detector and a model detector, which is completely optimized to the physics requirements, will also be discussed.
Speaker: elke-caroline Aschenauer (BNL)
• 14:20
Baseline design of an eRHIC Detector and Interaction Region 20m
The long-term upgrade plan for the RHIC facility foresees the addition of a high-energy polarized electron beam to the existing hadron machine, thus converting RHIC into an Electron-Ion Collider (eRHIC) with luminosities exceeding $10^{33} cm^{-1} s^{-1}$ [1]. The main physics topics to be explored at this new facility are (i) the polarized sea quark and gluon distributions in the nucleon, (ii) QCD dynamics of the low-x, high density gluon regime, (iii) hadronization and energy loss in the nuclear medium. A dedicated eRHIC detector, designed to efficiently register and identify deep inelastic electron scattering (DIS) processes in a wide range of center-of-mass energies available with the new collider is one of the key elements of this upgrade. The detector and interaction region design will be shown, technology choices discussed, and the first physics simulation results presented. [1] A. Accardi ${\it et~al.}$, "Electron Ion Collider: The Next QCD Frontier - ${\it Understanding ~the ~glue ~that ~binds ~us ~all}$" (EIC White Paper), arXiv:1212.1701 (2012).
Speaker: Dr Alexander Kiselev (Brookhaven National Laboratory)
• 14:40
Physics opportunities at the MEIC at JLab 20m
The Electron-Ion Collider (EIC) is envisioned as the next-generation US facility for exploring the strong interaction. The Medium-energy EIC (MEIC) is the first stage of the EIC at Jefferson Lab (JLab), designed to support the full program for the generic EIC, aimed at mapping the spin- and spatial structure of the quark and gluon sea in the nucleon, understanding the emergence of hadronic matter from color charge, and probing the gluon fields in nuclei. The kinematic coverage of the MEIC will on one end connect to JLab 12 GeV, and on the other to HERA (or a future LHeC). In order to achieve these goals, the accelerator is designed to provide high performance for polarized protons, deuterons, and other light ions, as well as different species of heavy ions, and will accommodate a full-acceptance detector able to measure the complete final state. In particular, it will tag spectators with a resolution << than the Fermi momentum, catch all nuclear and partonic target fragments, and to provide a wide coverage in -t for recoil baryons from exclusive (diffractive) reactions at all beam energies. The combination of a high luminosity, polarized lepton and ion beams, and detectors fully integrated with the accelerator will make the EIC a quantum leap in our understanding of the fundamental structure of matter.
• 15:00
eSTAR - a detector for eRHIC 20m
A high-luminosity polarized Electron Ion Collider (EIC) has been proposed to address 1) the distribution of the sea quarks and gluons, and their spins, in space and momentum inside the nucleon, 2) the dynamics of the gluon-dense regime in nuclei, 3) hadronization and energy loss in the nuclear medium. Such an EIC can be realized by the addition of an electron beam to the existing Relativistic Heavy Ion Collider (RHIC). This facility is called eRHIC. The STAR experiment, one of the two major experiments at RHIC, intends to evolve itself into eSTAR, a detector suitable for the initial stage of eRHIC. The evolution of STAR to eSTAR will be discussed in combination with detector upgrades and an assessment of eSTAR physics performance.
Speaker: Ernst Sichtermann (Lawrence Berkeley National Laboratory)
• 15:20
ePHENIX: An Electron Ion Collider (EIC) Detector Built Around the BaBar Magnet 20m
As a particular realization of an electron ion collider (EIC), the eRHIC project envisions the addition of a high intensity polarized electron beam to the existing RHIC facility, providing e+p and e+A collisions and enabling precision studies of the partonic structure of hadronic matter. To fully exploit the physics potential of eRHIC, the PHENIX Collaboration is proposing a detector built upon sPHENIX, a planned upgrade of the current PHENIX experiment. This new detector, ePHENIX, uses the sPHENIX superconducting solenoid and barrel calorimetry and adds to this foundation precision tracking, particle-identification and calorimetry in the barrel, electron-going and hadron-going directions, opening a broad range of exciting EIC physics measurements (see http://arxiv.org/abs/1402.1209). We give an overview of ePHENIX detector design and discuss its broad capabilities for both nucleon structure imaging and high density nuclear matter studies.
Speaker: Alexander Bazilevsky (Brookhaven National Laboratory)
• 15:40
fsPHENIX: A Detector for the Study of Nucleon Spin Structure and Cold Nuclear Matter at RHIC 20m
In the next decade the Relativistic Heavy Ion Collider (RHIC) will embark on detailed studies of the Quark Gluon Plasma with a major upgrade to the PHENIX detector, known as sPHENIX. To fully exploit the capabilities of sPHENIX and RHIC in spin-polarized p+p and p+A collisions the PHENIX Collaboration is proposing new instrumentation in the forward (proton-going) direction as an addition to the base sPHENIX detector. This project, know as fsPHENIX, will enable new measurements of spin asymmetries in jet production (both inter- and intra-jet), Drell Yan, and studies of cold nuclear matter using the unique capabilities of the RHIC collider to provide spin polarized p+A collisions. We will give an overview of the fsPHENIX design, its relationship to sPHENIX and ePHENIX, and physics goals of the proposed detector.
Speaker: John Lajoie (Iowa State University, for the PHENIX Collaboration)
• 16:00
Probing Gluon Saturation through Dihadron Correlations at an Electron-Ion Collider 20m
It is the ultimate goal of nuclear physics to understand the emergence of nuclear structure and dynamics in terms of quarks and gluons. Although past experiments were successful in determining the quark behavior in the nucleon and light nuclei, the gluons that determine the essential features of the strong interactions, remain largely unexplored. Of great interest is especially the high parton density (small x) regime where gluon self-interaction is expected to dominate and lead to parton saturation. Two-particle azimuthal angle correlations have been reckoned to be one of the most direct and sensitive probes to access the underlying gluon dynamics. In this talk, we will report on detailed studies of dihadron correlation measurements in ep and eA collisions taking into account saturation effects as well as parton shower processes. The potential of using these measurements to study the saturation regime will be discussed.
Speaker: J.H. Lee (Brookhave National Laboratory)
• 16:20
Coffee break 30m
• 16:50
eA collisions at the LHeC and FCC 20m
The Large Hadron Electron Collider (LHeC) is a proposed facility which will exploit the LHC and FCC heavy ion beams for electron-nucleus scattering, using either a new 60 GeV electron accelerator or one of the FCC 'ee' beams. The kinematic coverage extends beyond previous deep inelastic lepton-ion experiments by nearly four orders of magnitude at low Bjorken-x and towards higher $Q^2$. This contribution summarises the content of the simulations in the Conceptual Design report, plus its relation with the LHC with emphasis on pPb data, and the outlook towards a Technical Design report. After an introduction on the open problems in pA and eA collisions and the expected impact on the heavy ion program, we show inclusive observables and new results on the resulting constraints on nuclear parton densities. We then analyse the possibilities for inclusive and exclusive diffraction and the opportunities that they offer to reveal the non-linear dynamics which tame the low-x growth of parton densities. Finally, we discuss semi-inclusive measurements that will clarify the mechanism of hadronisation and QCD radiation inside the nuclear medium.
Speaker: Guilherme Teixeira De Almeida Milhano (Instituto Superior Tecnico (PT))
• 17:10
Higgs in ep and the FCC-he project 30m
The LHeC with a high luminosity of $O($ab$^{-1})$ gives a unique access to the WW-H and ZZ-H production modes and to various decay channels, as into $b\bar b$, $c\bar c$ and $\tau^+\tau^-$, which are difficult to study precisely at the LHC because of the more involved experimental and theoretical conditions. The FCC-he promises access to the $t\bar t$H and H-HH channels which have too small cross sections at the LHeC. The talk presents an overview on the progress in studies of the opportunities for Higgs physics in ep, which includes couplings, CP properties and different distributions.
Speaker: Monica D'Onofrio (University of Liverpool (GB))
• 17:40
LHeC detector design and simulation 20m
The Large Hadron Electron Collider (LHeC) is a proposed facility that will exploit the LHC beams for electron-proton/nucleus scattering, using a new 60 GeV electron accelerator. A detector concept is presented for the measurement of precision deep inelastic scattering phenomena including the reconstruction of Higgs decay final states with maximum acceptance. An overview is also given on the chosen technologies as well as steps towards simulating the LHeC detector using the DD4HEP framework. Aspects are also presented for measurements of forward (p,n) and backward particle (e,$\gamma$) production as it is required for diffractive and precision DIS physics. Finally, first considerations are included as to how a DIS detector could be built when exposed to the 50 TeV proton beam and the $O(100)$ GeV electron beam with the FCC configuration.
Speaker: Paul Newman
• 18:00
Belle II 20m
Speaker: Maria Rozanska (Polish Academy of Sciences (PL))
• 19:00 22:00
Social programme: Conference dinner
• Thursday, 1 May
• 08:30 12:20
WG3: Electroweak Physics and Beyond the Standard Model C (BUW)

### C

#### BUW

Conveners: Anna Kaczmarska (Polish Academy of Sciences (PL)), Krzysztof Turzynski (University of Warsaw), Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR)), Milada Muhlleitner (KIT - Karlsruhe Institute of Technology (DE))
• 08:30
BSM Primary effects 20m
We show that with the measurement of the Higgs decays all deformations of the dimension 6 extension of the Standard Model are completely constrained by a set of 18 observables (barring deformations involving four fermions). We construct the dimension 6 extension of the Standard Model and identify primary directions in the space of deformations related to these 18 observables. This allows us to write the dimension 6 Lagrangian as a function of these observables, so that predictions for any other process can be extracted as a funtion of these 18 measurements. We also discuss the dimension 6 lagrangian at 1-loop level.
Speaker: Sandeepan Gupta (Universitat Autònoma de Barcelona (ES))
• 08:50
Search for heavy resonances at the LHC 30m
Resonances decaying into a pair of particles are an obvious place to look for phenomena beyond the Standard Model. This talk summarizes recent results on searches for resonances in pairs of jets, lepton pairs, leptons and missing transverse energy and photon+jet. Various models models are considered such as Z' and W', Randall-Sundrum gravitons as well as the ADD large extra dimension scenario, excited quarks, quantum black hole and contact interactions. Results from sqrt(s) = 8 TeV are presented.
Speaker: Anirban Saha (Universita e INFN (IT))
• 09:20
Search for resonant diboson production at the LHC 30m
The study of electroweak boson pair production is a powerful test of the spontaneously broken gauge symmetry of the Standard Model (SM) and can be used to search for phenomena beyond the SM. Heavy particles decaying to gauge boson pairs are predicted by many scenarios of new physics, including Extra Dimensions, and Technicolor models. We present generic searches for a heavy particle decaying to a pair of boson. The talk presents results from searches done in several gauge bosons decay channels collected by the ATLAS and CMS experiments at the LHC with sqrt(s) = 8 TeV.
Speaker: Matthias Ulrich Mozer (KIT - Karlsruhe Institute of Technology (DE))
• 09:50
Limitation of EFT for DM interactions at the LHC 20m
We discuss the limitations to the use of the effective field theory approach to study dark matter at the LHC. We introduce and study a few quantities, which quantify the error made when using effective operators to describe processes with very high momentum transfer. Firstly, we study the full list of operators connecting fermion DM to quarks and gluons, corresponding to integrating out a heavy mediator in the s-channel; secondly, we provide analytical results for the validity of the EFT description for both \sqrt{s}=8 TeV and 14 TeV; thirdly, we make use of a MonteCarlo event generator approach to assess the validity of our analytical conclusions. We apply our results to revisit the current collider bounds on the ultraviolet cut-off scale of the effective field theory and show that these bounds are weakened once the validity conditions of the effective field theory are imposed.
Speaker: Giorgio Busoni
• 10:10
Coffee break 20m
• 10:30
Non-neutralino Dark Matter 20m
Dark matter is mysterious object that we have to find soon. Many different candidates of dark matter have been suggested up to now. I will give an overview on the dark matter candidate other than neutralino dark matter and their phenomenology.
Speaker: Ki-Young Choi (Korea Astronomy and Space Science Institute)
• 10:50
Searches for mono-X at the LHC 30m
If Dark Matter interacts weakly with Standard Model particles it can be produced at the LHC and identified via initial state radiation (ISR) of the incoming partons. The signature left in the detector is that of the ISR particle (jet, photon, Z or W) recoiling off of the invisible Dark Matter particles, resulting in a large momentum imbalance. Similar signatures result from the compactification of extra spatial dimensions in the Arkani-Hamed, Dimopoulos, and Dvali model resulting in a Kaluza-Klein tower of massive graviton modes. The mono-X signature is also sensitive to a large class of SUSY models. However, since the scalar interaction between DM particles and quarks is proportional to the quark mass, the sensitivity for this case can be further improved in searches with final states including the top quark. The talk presents results from searches for new physics in final states containing a single jet, photon, W or Z boson, and a single or a pair of top quarks accompanied by missing transverse energy studied by the ATLAS and CMS experiments at the LHC.
Speaker: Arely Cortes Gonzalez (Universitat Autònoma de Barcelona (ES))
• 11:20
Searches for vector-like quarks, ttbar resonances and W' to tb with ATLAS and CMS 30m
33: New physics Searches with Top-Like Final States In many models of physics beyond the Standard Model the coupling of new physics to third generation quarks is enhanced and signatures are expected that mimic top production. We present a review of non-MSSM based searches for new physics beyond the standard model in final states containing top quarks and/or bottom quarks. This includes includes searches for heavy gauge bosons, excited quarks, chirall and vector-like top quark partners. The searches span a range of final states, from multi-leptonic to entirely hadronic, and many results use novel analysis techniques to reconstruct the highly boosted final states that are created in these topologies. The searches are performed on data collected with the CMS experiment in proton-proton collisions at the LHC at a centre-of-mass energy of 7 and 8 TeV. 107: Searches for vector-like quarks, ttbar resonances and W' to tb with the ATLAS detector (joint with the TOP group) Various extensions of the Standard Model predict the existence of new types of quarks. We report on several search channels such as vector-like quarks decaying to a Higgs boson and a top quark or to a W boson and a b quark or to a Z boson and a b or top quark. The talk presents results from searches for new resonances decaying to a top-antitop or a top-b-jet pair, including the use of boosted top quark reconstruction techniques. These searches use the data sample recorded in 2012 at sqrt(s)=8 TeV centre-of-mass energy by the ATLAS experiment at the LHC.
Speaker: Thomas Peiffer (Hamburg University (DE))
• 11:50
Searches for new Physics in events with multiple leptons at the LHC 30m
Events containing several leptons are useful probes of new phenomena due to the low background from Standard Model processes. We look for anomalous production of prompt like-sign leptons or events with three or more leptons, as well as search for excited leptons, heavy leptons and heavy neutrinos. The searches use data recorded in 2012 at sqrt(s)=8 TeV centre-of-mass energy by the ATLAS and CMS experiments at the LHC.
Speaker: Olga Igonkina (NIKHEF (NL))
• 08:30 12:30
WG5: Heavy Flavours D (BUW)

### D

#### BUW

Conveners: Anze Zupanc (Jozef Stefan Institute), Martin Gorbahn (Liverpool University), Vanya Belyaev (ITEP Institute for Theoretical and Experimental Physics (RU))
• 08:30
Production of charmonium(-like) and their botomonium counterparts at ATLAS 30m
A precise understanding of the relative contributions to Charmonium production from prompt and non-prompt production modes is necessary in order to better understand the various charmonium production modes and their properties. We present new, double-differential production cross-section measurements of the J/psi, psi(2S) and X(3872) charmonium states, extending into new kinematic environments with high precision. The results are presented separately for prompt and non-prompt production modes, and relative production rates for psi(2S) to J/psi are also presented. The fractions of J/psi and psi(2S) that are produced from the decay of a B hadron are also measured in fine pT and rapidity intervals over the ATLAS acceptance region, which will provide important input to modelling of heavy flavour production for future measurements. Results compared with the latest theoretical calculations and models. The existence of the X(3872) suggests the presence of bottomonium counterpart. Search for X_b in the final state of Upsilon pi pi is presented.
Speaker: Susan Cheatham (McGill University (CA))
• 09:00
Studies of quarkonium production at BABAR 20m
Conventional and exotic quarkonia can be produced at the B factories through several mechanisms, as initial state radiation, two-photon fusion, and B-meson decays. We report on the most recent results obtained at BABAR.
Speaker: Gianluigi Cibinetto (INFN Ferrara)
• 09:20
Quarkonia and quarkonia-like spectroscopy at LHCb 20m
The latest years have seen a resurrection of interest in searches for exotic states motivated by tantalising observations by Belle and CDF. Using the data collected at pp collisions at 7 and 8 TeV by the LHCb experiment we present studies of the X(3872) properties including its decay rate to Psi(2S)gamma, as well as studies of putative states such as the Z(4430)+.
Speaker: Tomasz Skwarnicki (Syracuse University (US))
• 09:40
Spin effects in Bottomonium at Belle 20m
Spin effects have a dominant role in the understanding of the dynamic of the Bottomonium system, both in the transitions and in the correlation among light hadrons being produced in their annihilation. Naively we expect a suppression of the transitions with spin flipping terms, but recent results on $\eta$ transitions from $\Upsilon(4S)$ and $\Upsilon(5S)$ challenge this approach. The most recent results from Belle on this field will help to clarify the role of the spin in the modeling of the single- and two-meson transitions. Besides this the Belle collaboration is performing an extensive series of studies on baryon production in bottomonium decays, meant to address the two-baryon correlation in $\Upsilon(1S)$ annihilation and the precise measurement of hyperon inclusive production rates in $e^+e^-$ collision. The search for the long sought $H$ dibaryon is part of this effort.
Speaker: Umberto Tamponi (Universita e INFN, Torino (IT))
• 10:00
Quarkonia: a theoretical framework 30m
I discuss heavy quarkonium spectroscopy from the perspective of modern effective field theories for non-relativistic particles. These provide a framework suitable to describe in a systematic fashion all the relevant observables (cross-sections, widths, transitions, masses, ...). They may be also extended to describe quarkonia in a medium.
Speaker: Antonio Vairo (Institut fuer Theoretische Physik-Ruprecht-Karls-Universitaet H)
• 10:30
Coffee break 30m
• 11:00
Charmed Spectroscopy at LHCb 20m
The 7 and 8 TeV pp collision data collected by the LHCb experiment during 2011 and 2012 provide a rich sample of heavy flavour production and decays in which to study hadron properties. We present a summary of the recent experimental results from LHCb including studies of D_J mesons decaying to D(*)pi. We also report a search for the doubly charmed baryon Xi_cc^+
Speaker: Liang Zhong (Tsinghua University (CN))
• 11:20
Search for doubly-charmed baryons and study of charmed-strange baryon states at Belle 20m
Baryon states have provided excellent testing ground of QCD and our understanding of strong interactions. In recent years, there has been much experimental progress in charmed baryons from the Belle and BaBar experiments but there are no experimentally established doubly-charmed baryons. The existing evidence for doubly-charmed baryon \Xi_{cc}^+ from the SELEX experiment has not been supported by any other experiment. In this talk, we present the search for doubly charmed baryons in the e+ e- collision at or near \sqrt{s} = 10.58 GeV performed by Belle, with its full data sample of 980 fb^-1 produced by the KEKB collider and collected by the Belle detector. In addition, we report newly measured properties of the charmed-strange baryon, \Xi_{c}(2645)^+.
Speaker: Yuji Kato
• 11:40
Spectroscopy and decay properties of b-hadrons with ATLAS 20m
ATLAS has performed searches and accurate measurement of heavy hadrons, with results including the first observation of the chi_b(3P) Bottomonium states and the most accurate measurement of the Lambda_b lifetime. New results in this program are discussed, including searches for excited b-hadrons, new decay modes of b-hadrons.
Speaker: Andrew Stephen Chisholm (University of Birmingham (GB))
• 12:00
Properties and decays of the Bc meson 20m
The Bc meson is the only weakly decaying doubly heavy meson, which makes it an very interesting system to study. LHCb has recently measured its lifetime, mass and many decay channels, including for the first time a decay of the c-quark.
Speaker: Lucio Anderlini (Laboratoire d'Annecy de Physique de Particules)
• 08:30 12:30
WG6+WG7 Joint Session: Spin Physics + Future experiments Auditorium (BUW)

### Auditorium

#### BUW

Conveners: Abhay Deshpande (Stony Brook University), Alexei Prokudin (Jefferson Lab), Alice Valkarova (Charles University (CZ)), Barbara Pasquini (University of Pavia), Ernst Sichtermann (Lawrence Berkeley National Laboratory), Yann Bedfer (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 08:30
Gluonic Excitations and Experimental Hall-D at Jefferson Lab 25m
A new tagged photon beam facility is being constructed in experimental Hall-D at Jefferson Lab as a part of the 12 GeV upgrade program. The 9 GeV linearly-polarized photon beam will be produced via coherent Bremsstrahlung using the CEBAF electron beam, incident on a diamond radiator. The GlueX experiment in Hall-D will use this photon beam to search for and study the pattern of gluonic excitations in the meson spectrum produced through photoproduction reactions with a liquid hydrogen target. Recent lattice QCD calculations predict a rich spectrum of hybrid mesons, that are formed by exciting the gluonic field that couples the quarks. A subset of these hybrid mesons are predicted to have exotic quantum numbers which cannot be formed from a simple $q\bar{q}$ pair, and thus provide an ideal laboratory for testing QCD in the confinement regime. In this talk the status of the construction and installation of the GlueX detector will be presented, in addition to simulation results for some reactions of interest in hybrid meson searches. Finally, we will present some highlights from the other proposed Hall-D experimental programs.
Speaker: Justin Stevens (Massachusetts Institute of Technology)
• 08:55
The GPD program at COMPASS II 20m
The high energy polarised muon beam available at CERN with the option of using positive or negative muons with opposite polarisation gives COMPASS an excellent possibility to study generalised parton distributions via deeply virtual Compton scattering and hard exclusive meson production. In a first step we will use an unpolarised proton target to measure the $x_{Bj}$-dependence of the $t$-slope of the DVCS cross section to observe a possible shrinkage of the nucleon with increasing $x_{Bj}$. Furthermore, the beam charge and spin difference and sum will be measured over a wide kinematic range to determine the Compton form factor related to real and imaginary parts of the GPD $H$. As a second step we consider to use a transversely polarised proton target to collect data to constrain the GPD $E$. An exploratory measurement was performed in 2012 with the COMPASS spectrometer upgraded with a proton recoil detector surrounding a 2.5 m long liquid hydrogen target and an enlarged acceptance for photon detection. The status of the analysis and the perspectives for the planned measurements in 2016/17 will be discussed.
Speaker: Eva-Maria Kabuss (Johannes Gutenberg-Universitat)
• 09:15
Charged current DIS on longitudinally polarised nucleons at an EIC 25m
The proposed Electron-Ion Collider (EIC) aims to provide us with our clearest understanding yet of nucleon spin structure. Among its novel capabilities is the ability to study charged-current (CC) deep-inelastic scattering (DIS) on longitudinally polarised nucleons. This will provide invaluable and complimentary information to conventional, electromagnetic DIS, by probing a different set of quark flavour combinations, and giving access to high $Q^{2}$. We present the results of a detailed study into the prospects of CC polarised DIS at an EIC. Using a new version of the DJANGOH event generator, extended to handle polarised nucleons, we investigate the charged-current asymmetries, accounting for QED, QCD and electroweak radiative effects. Accounting for the expected EIC detector performance, we investigate the accuracy of the Jacquet-Blondel method in reconstructing the event kinematics from the hadronic final state. We find that the asymmetries are large and measurable with very high precision at an EIC. We then show the significant impact of such data when incorporated into an NLO global QCD analysis.
Speaker: Thomas Burton
• 09:40
Future prospects of di-jet production at forward rapidity constraining $\Delta g(x)$ at low $\mathbf{x}$ in polarized $\mathbf{\vec{p}+\vec{p}}$ collisions at RHIC 25m
One of the main objectives of the high-energy spin physics program at RHIC at BNL is the precise determination of the polarized gluon distribution function, $\Delta g(x)$. Polarized $\vec{p}+\vec{p}$ collisions at $\sqrt{s}=200\,$GeV and at $\sqrt{s}=500\,$GeV at RHIC provide a unique way to probe the proton spin structure using very well established processes in high-energy physics, both experimentally and theoretically. Inclusive measurements, such as inclusive jet production and hadron production, have so far been the prime focus of various released results at $\sqrt{s}=200\,$GeV constraining $\Delta g(x)$ for $0.05 < x < 0.2$. A recent global analysis provides for the first time evidence of a non-zero value of the gluon polarization $\int_{\tiny 0.05}^{\tiny 0.2}\Delta g (x)\, dx \,(Q^{2}=10\,{\rm GeV}^{2}) = 0.1^{+0.06}_{-0.07}$. First results of di-jet production at $\sqrt{s}=200\,$GeV by the STAR collaboration will allow a better constraint of the underlying event kinematics. Extending the current program to smaller values of $x$ is a key goal for the future high-energy spin physics program at RHIC. Forward di-jet production at the STAR experiment beyond the current acceptance of $-1<\eta<+2$, in particular those carried out at $\sqrt{s}=500\,$GeV, provides access to low $x$ values at the level of $10^{-3}$ where current uncertainties of $\Delta g(x)$ remain very large. Recent STAR jet results constraining $\Delta g(x)$ will be briefly summarized followed by a detailed presentation of the physics case of forward di-jet production at $\sqrt{s}=500\,$GeV for $+2.5<\eta<+4$ requiring an upgrade of the STAR forward detection system. This includes a discussion of the kinematic coverage and projected uncertainties for different di-jet topological configurations allowing to optimize the underlying partonic asymmetries to probe $\Delta g(x)$ below the currently accessible $x$ range as low as $10^{-3}$ in $x$. Those measurements will eventually be complemented by a future Electron-Ion Collider facility probing $\Delta g(x)$ in polarized $\vec{e}+\vec{p}$ collisions.
Speaker: Bernd Surrow (Temple University)
• 10:05
Physics opportunities with tagged deep inelastic scattering on polarized light nuclei at EIC 25m
Unpolarized and polarized deep inelastic lepton scattering off light nuclei (deuterium, He-3) with detection of spectator nucleon(s) at EIC offers unique opportunities to address fundamental open questions of QCD such as the spin structure of the neutron, the effect of nuclear binding on quark and gluon distributions, and the onset of coherent nuclear effects in high-energy processes. We present an overview of the physics of "tagged DIS" on polarized light ions, the key processes and observables, emphasizing the advantages of forward nucleon tagging in collider kinematics. We report about results of recent R&D simulating the extraction of the unpolarized and polarized neutron structure functions from tagged DIS off deuterium and demonstrating the feasibility of such measurements with EIC, and outline future directions in this effort.
• 10:30
Coffee break 30m
• 11:00
Timelike Compton scattering with a linearly polarized photon beam 20m
We study the polarization asymmetry in timelike virtual Compton scattering with a linearly polarized photon beam, in the generalized Bjorken scaling region and in the medium energy range which will be studied intensely at JLab12 experiments. We define new observables and show how they should help to access the polarized quark and gluon generalized parton distributions.
Speaker: Jakub Wagner (Institute for Nuclear Studies)
• 11:20
Transverse Spin Physics at PHENIX 20m
In the past decade, the data from transverse spin p+p from RHIC and polarized DIS experiments have enabled enormous progress in our understanding of the transverse spin dynamics in the proton. PHENIX Collaboration has carried out a very active program of transverse spin measurements including transverse spin asymmetries (TSSAs) in the production of light/heavy quark, of leading neutrons at forward rapidity, and of di-hadron/jet spin correlations in a wide kinematic range. All of these are crucial toward solving the transverse spin puzzle by disentangling the Sivers, the Collins and other spin effects. In the next two years we plan to collect new data on transversely polarized p+p and on p+A with high luminosities. In this talk, I will summarize the recent results from PHENIX, and discuss the near-term prospects of new physics measurements enabled by the newly installed silicon vertex tracker (FVTX) and the MPC-EX detectors currently under construction.
Speaker: Prof. Ken Barish (UC Riverside)
• 11:40
Drell-Yan physics at COMPASS 20m
The COMPASS experiment at CERN will start in the coming months its Drell-Yan (DY) physics program. This is the first transversely polarized target Drell-Yan measurement ever performed. Using a high intensity pion beam at 190 GeV/c momentum, the collected statistics over one year of data-taking will provide new insight to the transverse momentum dependent (TMD) parton distribution functions. During the last decade, COMPASS measured the azimuthal single spin asymmetries in semi-inclusive DIS (SIDIS) processes which contributed in a decisive way to the present knowledge of the nucleon TMDs. The predicted sign change of the Sivers and Boer-Mulders TMDs when accessed from SIDIS or from DY processes will be experimentally verified by this new DY measurement. The unpolarized Drell-Yan physics and the EMC effect studies, made possible by the inclusion of thin nuclear targets in the setup, will also be presented. The feasibility for a first look at the kaon induced Drell-Yan process will be discussed. The possibility to do detailed J\psi polarization studies with large statistics, bringing new input to a long-standing problem, will be discussed as well.
Speaker: Catarina Quintans (LIP-Lisbon)
• 12:00
Transverse single-spin asymmetries in $W^{\pm}$ and $Z^{0}$ bosons production in p+p collisions at RHIC 30m
The Sivers function $f^\perp_{1T}$ describes the correlation of parton transverse momentum with the transverse spin of the nucleon. There is evidence of a quark Sivers effect in semi-inclusive DIS (SIDIS) measurements. In SIDIS, the quark Sivers function is associated with a final state effect from the gluon exchange between the struck quark and the target nucleon remnants. On the other hand, for the virtual photon production in the Drell-Yan process, the Sivers asymmetry appears as an initial state interaction effect. As a consequence, the quark Sivers functions are of opposite sign in SIDIS and in Drell-Yan and this non-universality is a fundamental prediction from the gauge invariance of QCD. The experimental test of this sign change is one of the open questions in hadronic physics, and can provide a direct verification of TMD factorization. While luminosities required for a precise measurement of asymmetries in Drell-Yan production are challenging, $W^{\pm}/Z^{0}$ production is equally sensitive to the predicted sign change and can be well measured at the STAR experiment. The results can also provide essential input to study the evolution effects of the Sivers function, because of the high $Q^{2}$ in $W/Z^{0}$-production. The W boson kinematics are fully reconstructed from the decay lepton and the recoil, by employing a MC-based correction, thus avoiding the dilution that an asymmetry reconstructed from the decay lepton only would suffer. We will present progress toward the first measurement of the transverse single spin asymmetry, $A_{N}$, of the $W^{\pm}/Z^{0}$ bosons from the STAR experiment at RHIC.
Speaker: Dr Salvatore Fazio (Brookhaven National Laboratory)
• 08:50 12:20
WG2: Small-x, Diffraction and Vector Mesons B (BUW)

### B

#### BUW

Conveners: Lidia Maria Gorlich (Polish Academy of Sciences (PL)), Dr Mario Deile (CERN), Stephane Munier (Ecole polytechnique)
• 08:50
Study of Jpsi production and cold nuclear matter effects in pPb collisions 20m
The production of Jpsi mesons with rapidity 1.5 < y < 4.0 or −5.0 < y < −2.5 and transverse momentum pT<14GeV/c is studied with the LHCb detector in proton-lead collisions at a proton-nucleon centre-of-mass energy s_NN= Sqrt 5TeV. The analysis is based on a data sample corresponding to an integrated luminosity of about 1.6nb−1. For the first time the nuclear modification factor and forward-backward production ratio are determined separately for Jpsi mesons originating directly from the proton-nucleon collision and from b-hadron decays.
Speaker: Marco Adinolfi (University of Bristol (GB))
• 09:10
Dipole amplitude with uncertainty estimate from HERA data and applications in Color Glass Condensate phenomenology 20m
The Color Class Condensate offers a consistent framework to describe high-energy (small-x) data from various experiments. The non-perturbative input for these calculations, the dipole-target amplitude at initial Bjorken-x, can be obtained by performing a fit to electron-proton deep inelastic scattering data. We determine the initial condition for the small-x evolution equation (rcBK) from the HERA DIS data using a new parametrization that also keeps the unintegrated gluon distribution positive. We also obtain error sets that can be used to compute uncertainty estimates for any observable that depends on the dipole amplitude. As an application we compute single inclusive particle production in proton-proton and proton-nucleus collisions with uncertainty estimates. We show that the LHC data can be used to further constrain the initial dipole amplitude. In order to compute proton-nucleus collisions we generalize our dipole-proton amplitude to nuclear targets using only input from HERA and standard nuclear geometry. We obtain a good description with the available LHC nuclear suppression factor data. References: T. Lappi, H. Mäntysaari, in progress T. Lappi, H. Mäntysaari, Phys.Rev. D88 (2013) 114020
Speaker: Heikki Mäntysaari (University of Jyväskylä)
• 09:30
Diffractive vector meson production in ultraperipheral heavy ion collisions from the Color Glass Condensate 20m
Deep inelastic scattering is a powerful tool to study the structure of hadrons and test our understanding of the strong interaction. The precise proton structure function measurements done at HERA have been a crucial test for the Color Glass Condensate effective field theory description of the high energy hadronic interactions. Ideally one would want to continue the analysis with nuclear targets where gluon saturation effects are expected to be even stronger. Because the role of the electron in DIS events is to only act as a source of virtual photons, one can study the same physics in ultraperipheral (large impact parameter) heavy ion collisions. In these events the dominant process is the one where one nucleus acts as a photon source, and one is left with a similar photon-nucleus scattering as in DIS. Recently diffractive vector meson production in ultraperipheral collisions has gained a lot of theoretical and experimental attention, because the cross section is especially sensitive to the saturation effects and also probes the spatial distribution of gluons. For example the ALICE collaboration has measured the diffractive J/Psi cross sections in lead-lead collisions [1]. We calculate coherent and incoherent diffractive vector meson production from the Color Glass Condensate framework and compare our results and predictions with the ALICE data. We discuss the dependence on the vector meson properties and the modelling uncertainties. We also present predictions for proton-nucleus collisions. [2] [1] ALICE collaboration, Phys. Lett. B718 (2013) 1273, Eur.Phys.J. C73 (2013) 2617 [2] T. Lappi, H. Mäntysaari, Phys.Rev. C87 (2013) 032201, Phys.Rev. C83 (2011) 065202
Speaker: Heikki Mäntysaari (University of Jyväskylä)
• 09:50
ALICE REsults on Ultra-Peripheral Production 30m
Ultra-Peripheral production of vector mesons investigates those collisions where the impact parameter is larger than the sum of the radii of the two projectiles, implying that electromagnetic processes become dominant. For heavier vector mesons, they can provide a promising way to investigate nuclear shadowing (Pb-Pb) and the gluon structure function (p-Pb). The latest results from this programme will be discussed.
Speaker: Orlando Villalobos Baillie (University of Birmingham (GB))
• 10:20
Coffee break 40m
• 11:00
Exclusive photoproduction of charmonia in hadronic collisions 20m
We present results based on our new paper [1]. The amplitude for $\gamma p \to V p$ is calculated in a pQCD $k_{T}$-factorization approach. The coresponding total cross section for different unintegrated gluon distributions is calculated and compared with new HERA data for photon-proton collisions. We also compare the total cross section for $\gamma p \to V p$ reaction with recent data extracted by of the LHCb collaboration. The amplitude for $\gamma p \to V p$ is used to predict cross section for exclusive photoproduction of $J/\Psi$ and $\Psi'$ mesons in proton-proton collisions. Both Dirac and Pauli electromagnetic form factors are included in the calculation and results are compared with old results (only Dirac form factor). The effect of Pauli form factor is quantified. Absorption effects are included and their uncertainties are discussed. Different differential distributions e.g. in $J/\Psi$ ($\Psi'$) rapidity and transverse momentum are presented and compared with existing experimental data for Tevatron and LHC energy. [1] A.Cisek, W. Sch\"afer and A. Szczurek, a paper in preparation.
Speaker: Dr Anna Cisek (University of Rzeszow)
• 11:20
Central $\mu^+ \mu^-$ production via photon-photon fusion in proton-proton collisions with proton dissociation 20m
We report a study on the description of two-photon production of dimuons in proton-proton collisions. We focus on the region of high transverse momentum of the muon pairs, where contributions from proton dissociative events are important. Here one must go beyond the Weizsaecker-Williams approximation of collinear photons and take the photon transverse momenta into account. The resulting formalism in the high-energy limit can be understood as a type of $k_T$-factorization where the transverse momentum dependent photon fluxes play the role of ''unintegrated'' photon densities. We show that at large pair transverse momentum, the cross section becomes proportional to the unintegrated photon flux. The calculation of the unintegrated photon fluxes for dissociative events requires knowledge of proton structure functions in a broad range of $x_{Bj}$ and $Q^2$, which we will discuss. We also show a comparison with the LPAIR Monte-Carlo code.
Speaker: Wolfgang Schaefer (Institute of Nuclear Physics PAN)
• 11:40
Higgs production within $k_t$-factorization with unintegrated gluon distribution functions 20m
We calculate distribution of Higgs boson in rapidity and transverse momentum within $k_t$-factorization with different unintegrated gluon distribution functions from the literature (Kimber-Martin-Ryskin, Jung-Salam, Kutak-Stasto, Kwiecinski CCFM, Ivanov-Nikolaev) with leading order and next-to-leading order precision and with off-shell matrix elements. Special attention is devoted to the Kimber-Martin-Ryskin distribution which is known to describe well gauge boson (W and Z) production, Drell-Yan processes and heavy quark production. We discuss and quantify contributions from different regions of incoming gluon transverse momenta dividing the space into hard and soft regions. We discuss how these regions may be roughly related to fixed-order LO, NLO and NNLO calculations. We include also the decay of the Higgs boson into photons and compare results with recent preliminary data of the ATLAS Collaboration for the Higgs boson transverse momentum and rapidity distributions. The lowest order $k_t$-factorization contribution gives similar shape for Higgs boson transverse momentum as the experimental one but underpredicts the new ATLAS data. We discuss that the lowest-order $k_t$-factorization result does not include e.g. NLO collinear-factorization contributions which are known to be large. We show $k_t$-factorization NLO contributions ($g g \to H g$) for different UGDFs. For completeness we show also contribution of $WW$ fusion. In addition, we show distributions in azimuthal angle between photons and distributions in two-dimensional space of $p_{1t} x p_{2t}$ of transverse momenta of photons. M. Luszczak, A. Szczurek, a paper in preparation.
Speaker: Antoni Szczurek (Institute of Nuclear Physics)
• 12:00
Dipole model analysis of high precision HERA data 20m
We analyse, within a dipole model, the inclusive DIS cross section data, obtained from the combination of the H1 and ZEUS HERA measurements. We show that these high precision data are very well described within the dipole model framework, which is complemented with a valence quark structure functions. We discuss the properties of the gluon density obtained in this way.
Speaker: Henri Paul Kowalski (Deutsches Elektronen Synchrotron (DESY))
• 09:00 12:10
WG4: QCD and Hadronic Final States F (BUW)

### F

#### BUW

Conveners: Daniel Britzger (Deutsches Elektronen-Synchrotron (DE)), Konstantinos Kousouris (CERN), Vladimir Braun (University of Regensburg)
• 09:00
LHC data challenges the contemporary parton-to-hadron fragmentation functions 20m
We will discuss the inclusive high-pT charged particle production in proton-proton and proton-antiproton collisions with a special emphasis on the recent LHC and Tevatron measurements. The experimental data are compared to the NLO perturbative QCD calculations employing various sets of parton-to-hadron fragmentation functions. Most of the theoretical predictions are found to disastrously overpredict the measured LHC and Tevatron cross sections, even if the scale variations and PDF errors are accounted for. The problem appears to arise from the presently too hard gluon-to-hadron fragmentation functions.
Speaker: Dr Hannu Paukkunen (University of Jyväskylä)
• 09:20
High Energy Jets at the LHC 20m
In this talk I will discuss recent developments in the High Energy Jets (HEJ) description of multi-jet events. This provides an all-order description of wide-angle QCD radiation. After discussing recent developments and extensions of the formalism, I will discuss new predictions for Higgs plus jets and Z plus jets. I will also discuss comparisons with experimental data and other Monte Carlo packages which illustrate the differences and advantages of the all-order predictions from all-order predictions in HEJ.
Speaker: Mr Medley Jack (University of Edinburgh)
• 09:40
Higgs boson as a gluon trigger 20m
In the forthcoming high-luminosity phase at the LHC, many of the most interesting measurements for precision QCD studies are hampered by conditions of large pileup, particularly at not very high transverse momenta. We study observables based on measuring ratios of color-singlet currents via Higgs boson and Drell-Yan production, which may be accessed also at large pileup, and used for an experimental program on QCD physics of gluon fusion processes in the LHC high-luminosity runs. We present results of Monte Carlo calculations for a few specific examples.
Speaker: Hans Van Haevermaet (University of Antwerp (BE))
• 10:00
Azimuthal decorelations in forward central dijets production at LHC within high energy actorization 20m
The results for azimuthal decorelations in production of forward and central jets in collision p+p and p+Pb are going to be presented. The considered cross section is obtained within framework of high energy factorization and makes use of gluon density obtained from BK equation extended to account for corrections of higher order.
• 10:20
Coffe break 30m
• 11:10
Hard exclusive J/\Psi photoproduction off a proton 20m
We study the photoproduction of J/\Psi mesons off a proton in the kinematical regime of large energies and scattering angles within the framework of perturbative QCD. The heavy charm-quark mass is providing the relevant hard scale in the process. In particular, it is the so-called hard scattering approach which is taken as theoretical basis for our investigations. There the hadrons are replaced by their valence Fock states during the hard scattering and the large transfered momentum is redistributed by additionally attaching hard gluons to these valence quarks. We can show that in our perturbative treatment not the graphs where the photon directly fluctuates into the c \bar{c} pair give the dominant contribution in the investigated kinematical regime, but the graphs where the photon first couples to the valence quarks of the proton. We also give explicite predictions for \gamma p -> J/\Psi p cross sections, which are compared to experimental data where possible.
Speaker: Dr Alexander Thomas Goritschnig (University of Graz)
• 11:30
FREE ENERGY AND DIRECT PHOTON EMISSION AT FINITE CHEMICAL POTENTIAL FROM QUARK-GLUON PLASMA 20m
We extend to investigate the evolution of free energy and direct photon production from quark-gluon plasma (QGP) considering finite chemical potential. The evolution of QGP formation at the chemical potential is done through finite value of quark mass.The evolution rate is found to be decreasing with chemical potential. We further study the direct photon emission from fireball of such QGP and found the result to be increasing function of chemical potential in all the channels of photon production. It also shows enhancement of photon emission in comparison to the other theoretical calculation of direct photon productions.
Speaker: Dr Yogesh Kumar (Department of Physics and Astrophysics)
• 11:50
Associated-quarkonium production 20m
In this talk, I discuss the growing interest to measure associated-quarkonium production in a number of channels at the LHC. Whereas back-to-back production of quarkonium + isolated photon provides a unique way to extract gluon TMDs [1], observables such as quarkonium + W/Z can be of great help to better understand the quarkonium production mechanism as well as to shed light on double-parton scatterings. Along these lines, quarkonium-pair production [4] is also a potentially rich source of information which has only started to be harvested. References: [1] Accessing the Transverse Dynamics and the Polarization of the Gluons inside the Proton at the LHC. By W. J. den Dunnen, J.P. Lansberg, C. Pisano, M. Schlegel. [arXiv:1401.7611 [hep-ph]]. [2] Next-to-leading-order QCD corrections to the yields and polarisations of J/Psi and Upsilon directly produced in association with a Z boson at the LHC. By B. Gong, J.P. Lansberg, C. Lorce, J.X. Wang. [arXiv:1210.2430 [hep-ph]]. JHEP 1303 (2013) 115. [3] Reassessing the importance of the colour-singlet contributions to direct J/psi + W production at the LHC and the Tevatron. By J.P. Lansberg, C. Lorce. [arXiv:1303.5327 [hep-ph]]. Phys.Lett. B726 (2013) 218-222. [4] Production of J/psi+eta(c) vs. J/psi+J/psi at the LHC: Impact of Real alpha_s^5 corrections. By J.P. Lansberg, H.-S. Shao. [arXiv:1308.0474 [hep-ph]]. Phys.Rev.Lett. 111 (2013) 122001.
Speaker: Jean-Philippe Lansberg (IPN Orsay, Paris Sud U. / IN2P3-CNRS)
• 12:30 14:00
Lunch break 1h 30m BUW

#### BUW

• 14:00 18:00
Social programme: Excursions - Your guides will wait for you in front of the conference building and show the way to busses. You will have to walk ~1 km to the bus. If you need assistance, contact the registration desk before lunch.
• 19:00 20:00
Social programme: Concert Royal Lazienki Park

#### Royal Lazienki Park

• Friday, 2 May
• 09:00 12:30
Plenary: Friday morning Auditorium (BUW)

### Auditorium

#### BUW

• 09:00
WG1 Highlights: Structure Functions and Parton Densities 20m Auditorium

### Auditorium

#### BUW

Speakers: Karol Kovarik, Richard David Ball (Edinburgh University), Vladimir Chekelian (MPI fuer Physik)
• 09:30
WG2 Highlights: Small-x, Diffraction and Vector Mesons 20m Auditorium

### Auditorium

#### BUW

Speakers: Lidia Maria Gorlich (Polish Academy of Sciences (PL)), Dr Mario Deile (CERN), Stephane Munier (Ecole polytechnique)
• 10:00
WG3 Highlights: Electroweak Physics and Beyond the Standard Model 20m Auditorium

### Auditorium

#### BUW

Speakers: Anna Kaczmarska (Polish Academy of Sciences (PL)), Krzysztof Turzynski (University of Warsaw), Maxime Gouzevitch (Universite Claude Bernard-Lyon I (FR)), Milada Muhlleitner (KIT - Karlsruhe Institute of Technology (DE))
• 10:30
Coffee break 30m Halls in front of Auditorium (BUW)

### Halls in front of Auditorium

#### BUW

• 11:00
WG4 Highlights: QCD and Hadronic Final States 20m Auditorium

### Auditorium

#### BUW

Speakers: Daniel Britzger (Deutsches Elektronen-Synchrotron (DE)), Konstantinos Kousouris (CERN), Vladimir Braun (University of Regensburg)
• 11:30
WG5 Highlights: Heavy Flavours 20m Auditorium

### Auditorium

#### BUW

Speakers: Anze Zupanc (Jozef Stefan Institute), Martin Gorbahn (Liverpool University), Vanya Belyaev (ITEP Institute for Theoretical and Experimental Physics (RU))
• 12:00
WG6 Highlights: Spin Physics 20m Auditorium

### Auditorium

#### BUW

Speakers: Barbara Pasquini (University of Pavia), Ernst Sichtermann (Lawrence Berkeley National Laboratory), Yann Bedfer (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
• 12:30 14:00
Lunch break 1h 30m BUW

#### BUW

• 14:00 18:00
Plenary: Friday afternoon Auditorium (BUW)

### Auditorium

#### BUW

• 14:00
WG7 Highlights: Future experiments 20m
Speakers: Abhay Deshpande (Stony Brook University), Alexei Prokudin (Jefferson Lab), Alice Valkarova (Charles University (CZ))
• 14:30
Particle physics from the European perspective 20m
Speaker: Sergio Bertolucci (CERN)
• 15:00
American particle and nuclear physics planning 20m
In the United States the planning process relevant to future deep inelastic scattering involves both the high energy physics and nuclear physics funding and the two communities. Within the past two years there have been several planning initiatives and there may be more to come. I will review the current status of both the planning and the plans.
Speaker: Hugh Montgomery (JLAB)
• 15:30
Particle physics from the Asian perspective 20m
Speaker: Mitsuaki Nozaki (Kobe University (JP))
• 16:00
Coffee break 30m
• 16:30
DIS outlook 30m
Speaker: Alfred Mueller (Columbia University)
• 17:00
Summary of IAC meeting 10m
Speaker: Aharon Levy (Tel Aviv University (IL))
• 17:10
Closing remarks 10m
Speaker: Barbara Badelek (University of Warsaw (PL))
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