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Displaying 296 contributions out of 296
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
By using the very first proton-proton collision data of the LHC Run II, LHCb performed a series of measurements, notably including the cross-sections for heavy boson, quarkonia, beauty and charm productions. The results have been carried out by exploiting a new scheme for the LHCb software trigger that gives the possibility to finalise physics analyses directly from data objects produced by the on ... More
Presented by Tomasz SZUMIAK on 12 Apr 2016 at 2:30 PM
Session: WG7 Future Experiments
Track: Future Experiments
The recent proposal of CepC and SppC, the next energy frontier e+e- and pp circular colliders by IHEP, China, in a common accelerator complex, provides an opportunity to realize collisions of protons or ions with electrons or positrons in an ultra-high range of center-of-mass energy up to 4.2 TeV. This paper presents a preliminary design study of this high energy e-p/A collider based on the CepC-S ... More
Presented by Dr. Yuhong ZHANG on 13 Apr 2016 at 9:46 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
Although Parton Distribution Functions are the fundamental objects describing the inner structure of hadrons, there exists so far no computation of them from first principles. The most promising candidate for such calculation, lattice QCD, performed successful computations for the masses, charges and form factors but not of the distributions themselves. The reason for this is that quark distributi ... More
Presented by Dr. Fernanda STEFFENS on 14 Apr 2016 at 11:40 AM
Session: WG6/WG7 joint session (spin+future exp.)
Track: Future Experiments
This talk will concentrate on the plans towards equipment and science utilizing the 12-GeV Upgrade at Jefferson Lab beyond the first three years of planned operations. Experiments are geared towards precision spatial and momentum imaging of hadrons utilizing specialized detector and/or target systems. For example, the Neutral-Particle Spectrometer in Hall C is presently under construction, and pla ... More
Presented by Rolf ENT on 13 Apr 2016 at 3:16 PM
Session: WG7 Future Experiments
Track: Future Experiments
 The 2015 Long Range Plan for Nuclear Science in the US recommended a high-energy high-luminosity polarized Electron-Ion Collider as the highest priority for new facility construction following the completion of presently ongoing projects. 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 ... More
Presented by Dr. Alexander KISELEV on 13 Apr 2016 at 11:00 AM
Session: WG7 Future Experiments
Track: Future Experiments
In this talk, the status of the design of a detector for studying energy-frontier DIS at the LHeC and the FCC-he will be presented. Its different parts will be discussed: interaction region, tracking, EM calorimeter, solenoid, hadronic calorimeter and muon detector. Besides, the software framework that is currently employed, developed within DD4HEP, will also be presented.
Presented by Nestor ARMESTO PEREZ
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
In this talk I will present a novel determination of the mass of the charm quark extracted by analyzing the statistical quality of fits of parton distribution functions (PDFs) to inclusive and exclusive charm deep-inelastic scattering (DIS) cross-section data from Runs I and II of the HERA collider. We employ the running mass definition in the MSbar scheme, which improves the perturbative sta ... More
Presented by Dr. Valerio BERTONE on 12 Apr 2016 at 5:10 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We use the holographic light front wavefunction for the $\phi$ meson obtained from AdS/QCD, in conjunction with the Color Glass Condensate dipole cross-section whose parameters are fitted to the most recent precise combined HERA data on inclusive Deep Inelastic Scattering, to compute the rate for diffractive $\phi$ electro-production. Our predictions are in good agreement with the available data ... More
Presented by Prof. Mohammad AHMADY on 12 Apr 2016 at 11:40 AM
Session: Plenary
Presented by Prof. Thomas GEHRMANN on 11 Apr 2016 at 11:00 AM
Session: Plenary
Presented by Dr. Fabrizio CAOLA on 15 Apr 2016 at 10:05 AM
Session: Plenary
on 15 Apr 2016 at 9:30 AM
Session: Plenary
Presented by Jan KRETZSCHMAR on 15 Apr 2016 at 9:45 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
In the HERAPDF2.0 PDF analysis it was noted that the fit $chi^2$ worsens significantly at low $Q^2$ for both NLO and NNLO fits. The turn over of the reduced cross section at low-$x$ and low $Q^2$ due to the contribution of the longitudinal cross section $F_L$ is also not very well described. In this paper the prediction for $F_L$ is highlighted and the corresponding extraction of $F_2$ from t ... More
Presented by Prof. Amanda COOPER-SARKAR, Prof. A. COOPER-SARKAR, Prof. Amanda COOPER-SARKAR on 12 Apr 2016 at 9:40 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
The Lam-Tung relation, a pertubative QCD, ``Callan-Gross-like'' correlation of the azimuthal and polar angles of leptonic products relative to the initial hadronic plane in multiple frames, defines a standard component of any analysis using Drell-Yan as a nucleon probe. In at least three experiments involving Drell-Yan between various species of pions and nuclei at CERN and Fermilab, the existence ... More
Presented by Mr. Bryan RAMSON on 13 Apr 2016 at 9:20 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The production of weak gauge bosons in association with heavy flavored mesons at the LHCb conditions is considered, and a detailed study of the different contributing processes is presented including single and double parton scattering mechanisms. We conclude finally, that double parton scattering dominates the production of same-sign WD states, as well as the production of W- bosons associated wi ... More
Presented by Dr. Maxim MALYSHEV on 14 Apr 2016 at 12:12 PM
Session: Plenary
Presented by Dr. Johannes KNAPP on 11 Apr 2016 at 2:30 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
We present a first numerical implementation of the Loop-Tree Duality (LTD) method for the direct numerical computation of multi-leg one-loop Feynman integrals. We discuss in detail the singular structure of the dual integrands and define a suitable contour deformation in the loop three-momentum space to carry out the numerical integration. Then, we apply the LTD method to the computation of ultrav ... More
Presented by Dr. Grigorios CHACHAMIS on 13 Apr 2016 at 12:20 PM
Session: WG6 Spin Physics
Track: Spin Physics
Studies of spin-azimuthal asymmetries in semi-inclusive production of hadrons have been widely recognized as key objectives of the JLab 12 GeV upgrade and a driving force behind the construction of the Electron Ion Collider. Various assumptions involved in preliminary extraction of underlying transverse momentum dependent partonic distributions (TMDs) from available data, have yet to allow credibl ... More
Presented by Harut AVAGYAN on 12 Apr 2016 at 12:20 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
In this talk a study of the production of Mueller-Navelet jets at 13 TeV LHC will be presented, including the BFKL resummation effects and investigating three different variants of the BLM scale optimization method. It will be shown how the cross section and the azimuthal observables are affected by the exclusion of the events where, for a given rapidity interval between the two jets, one of these ... More
Presented by Mr. Francesco Giovanni CELIBERTO on 12 Apr 2016 at 2:30 PM
Session: Plenary
Track: Electroweak Physics and Beyond the Standard Model
Presented by Prof. Kevin BLACK on 15 Apr 2016 at 9:00 AM
Session: WG7 Future Experiments
Track: Future Experiments
The Belle II experiment at the SuperKEKB collider is a major upgrade of the KEK ``$B$ factory'' facility in Tsukuba, Japan. Phase 1 commissioning of the main ring of SuperKEKB has started in February 2016 and first physics data will be recorded in the second half of 2017 during the so-called Phase~2 commissioning, when the Belle II detector will be operated still without its vertex detector. I ... More
Presented by Dr. Hua YE on 13 Apr 2016 at 5:39 PM
Session: WG7 Future Experiments
Track: Future Experiments
The Belle II experiment at the SuperKEKB collider is a major upgrade of the KEK ``$B$ factory'' facility in Tsukuba, Japan. The machine is designed for an instantaneous luminosity of $8\times 10^{35}$~cm$^{-2}$\,s$^{-1}$, and the experiment is expected to accumulate a data sample of about 50 ab$^{-1}$ well within the next decade. With this amount of data, decays sensitive to physics beyond the Sta ... More
Presented by Dr. Gianluca INGUGLIA on 13 Apr 2016 at 6:02 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We discuss recent activities of the CT global analysis group. This includes an update of CT14 to include the HERA1+2 combined data set, discussion of CT14 special sets such as CT14QED, intrinsic charm or asymmetric strange studies, and other current analyses based on CT14.
Presented by Carl SCHMIDT, Carl SCHMIDT on 12 Apr 2016 at 11:00 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The measurement of Higgs pair production will be a cornerstone of the LHC program in the coming years. Double Higgs production provides a crucial window upon the mechanism of electroweak symmetry breaking and has a unique sensitivity to the Higgs trilinear coupling. We study the feasibility of a measurement of Higgs pair production in the b ̄bb ̄b final state at the LHC. Our analysis is based on ... More
Presented by Dr. Nathan HARTLAND on 13 Apr 2016 at 5:30 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Bose–Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of 1H, 2H, 3He, 4He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation funct ... More
Presented by Dr. Gevorg KARYAN on 12 Apr 2016 at 9:15 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
After carefully explaining how fixed and variable flavour schemes arise in the context of DIS, I will discuss how one can consistently combine the merits of the two. The final matched result includes the full power corrections of the fixed-flavour scheme and resums the potentially large logs. I will then talk about the application of this approach to the case of bbH at the LHC and present a f ... More
Presented by Andrew PAPANASTASIOU on 12 Apr 2016 at 5:50 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
An essential part of any factorisation proof is the demonstration that the exchange of Glauber gluons cancels for the considered observable. In this talk I will show that this can be done for the double Drell-Yan process (the double parton scattering process in which a pair of electroweak gauge bosons is produced), both for the integrated cross section and for the cross section differential in the ... More
Presented by Dr. Jonathan GAUNT on 14 Apr 2016 at 10:05 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The cross-section for central exclusive production of J/psi and Psi(2S) mesons at 13 TeV is measured using the LHCb detector. Proton dissociative backgrounds are significant reduced compared to previous measurements through the use of forward shower counters, recently installed for Run 2. Cross-section ratios to previous measurements at 7 TeV allow more precise tests of theoretical predictions a ... More
Presented by Prof. Ronan MCNULTY on 12 Apr 2016 at 4:50 PM
Session: WG6 Spin Physics
Track: Spin Physics
The latest measurements of charged pion, kaon, and unidentified hadron multiplicities in semi-inclusive deep-inelastic scattering from the COMPASS experiment at CERN are presented. The data were collected using a 160 GeV muon beam incident on an isoscalar 6LiD target. The large statistics collected cover a wide kinematic range in photon virtuality: 1 < Q2 < 50 (GeV/c)2, relative virtual-photon ene ... More
Presented by Dr. Erin SEDER on 12 Apr 2016 at 5:30 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
For Deep Inelastic neutrino-proton scattering in the combination $\nu P - \bar{\nu} P$, we compute the exact $\mathcal{O}(\alpha_s^3)$ perturbative QCD corrections to the charged-current structure functions $F_2$, $F_L$ and $F_3$. These results supersede previous approximations based on the first few Mellin moments by providing all-$N$ expressions for the coefficient functions. We discuss the nume ... More
Presented by Mr. Joshua DAVIES on 12 Apr 2016 at 12:36 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
The BESIII Experiment at the Beijing Electron Positron Collider (BEPCII) has accumulated the world's largest e+e- collision samples atψ(3770) peak, around theψ(4040) nominal mass, and at the Lambda_c-pair mass threshold which allow us to study decays of charmed mesons and baryons in a uniquely clean background. In this talk, we will review our recent results including: (1) the extractions of the ... More
Presented by Yu ZHANG on 12 Apr 2016 at 9:40 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We update predictions for lepton fluxes from the hadroproduction of charm quarks in the scattering of primary cosmic rays with the Earth's atmosphere. The calculation of charm-pair hadroproduction applies the latest results from perturbative QCD through next-to-next-to-leading order and modern parton distributions, together with estimates on various sources of uncertainties. Our predictions for th ... More
Presented by Sven-Olaf MOCH on 12 Apr 2016 at 3:30 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
I will discuss the extension of the FONLL variable flavour number scheme to account for a possible intrinsic component of the charm PDF. I will present the results of a PDF fit which includes a fitted charm PDF in the NNPDF framework, and discuss phenomenological implications.
Presented by Mr. Luca ROTTOLI on 13 Apr 2016 at 5:10 PM
Session: Plenary
Track: Heavy Flavours (Charm, Beauty and Top)
Presented by Mr. Mikhaylo LISOVYI, Maximilian STAHLHOFEN, Mr. Martijn MULDERS on 15 Apr 2016 at 12:00 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The coherent J/psi photoproduction cross section is measured in ultra-peripheral PbPb collisions at 2.76 TeV at the CMS experiment at the LHC. The J/psi mesons are reconstructed via their decay into muon pairs. In this talk, the measurement of the coherent J/psi photoproduction cross section as well as the neutron dependence break-up mode ratios for this process will be presented. These measuremen ... More
Presented by Daniel Tapia TAKAKI on 13 Apr 2016 at 2:50 PM
Session: WG4/WG5 joint session (HF+diffraction)
Track: Small-x, Diffraction and Vector Mesons
ALICE has measured the coherent photo-nuclear production of $\rho^0$, J/$\psi$ and $\psi(2S)$ vector mesons at mid-rapidity in ultra-peripheral collisions of lead nuclei. These processes provide information on the gluon structure of the nuclear target at low Bjorken-$x$. The talk will cover the results from LHC Run1 data, as well as discuss the current status and prospects for analyses with LHC Ru ... More
Presented by Prof. Guillermo CONTRERAS on 13 Apr 2016 at 4:50 PM
Session: WG6 Spin Physics
Track: Spin Physics
New investigations on the Collins functions have been made possible by recent e+ e− annihilation data released by the BaBar Collaboration. These data allow to directly infer the transverse momentum dependence of the Collins function for pions and, for the first time, attempt extractions of the kaon Collins function. In this talk, I will discuss our recent results of the analysis of these and oth ... More
Presented by Dr. J. Osvaldo GONZALEZ HERNANDEZ on 12 Apr 2016 at 6:10 PM
Session: WG1/WG3 joint session (EW+PDF)
Track: Structure Functions and Parton Densities
A simultaneous fit of parton distribution functions (PDFs) and electroweak parameters to HERA data on deep inelastic scattering is presented. The input data are the neutral current and charged current inclusive cross sections which were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In addition, the polarisation of the electron beam was taken into account for the ZEUS dat ... More
Presented by Mr. Volodymyr MYRONENKO on 13 Apr 2016 at 3:20 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
A summary of measurements of the fragmentation of charm quarks into a specific hadron is given. Measurements performed in photoproduction and deep inelastic scattering in e+-p, pp and e+e- collisions are compared, using up-to-date branching ratios. Within uncertainties, all measurements agree, supporting the hypothesis that fragmentation is independent of the specific production process. Compared ... More
Presented by Dr. Oleksandr ZENAIEV on 12 Apr 2016 at 4:30 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
World data for the F2 structure function for Iron, as measured by multiple charged lepton and neutrino scattering experiments, are compared. Data obtained from charged lepton and neutrino scattering at larger values of x are in remarkably good agreement with a simple invocation of the 18/5 rule, while a discrepancy in the behavior of the data obtained from the different probes well beyond the data ... More
Presented by Dr. Cynthia KEPPEL on 13 Apr 2016 at 11:20 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We perform a complete study of prompt double $J/\psi$ hadroproduction at leading order in the nonrelativistic-QCD factorization framework by including all possible pairings of the $c\bar{c}$ Fock states ${}^1\!S_0^{[8]}$, ${}^3\!S_1^{[1,8]}$, and ${}^3\!P_J^{[1,8]}$ with $J=0,1,2$. We find that the ${}^1\!S_0^{[8]}$ and ${}^3\!P_J^{[8]}$ channels of $J/\psi$ and $\psi^\prime$ production and t ... More
Presented by Dr. Zhiguo HE on 14 Apr 2016 at 11:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We present results for the NLO QCD corrections to the process $pp \to t\bar{t} j \to W^+W^-b\bar{b} j \to e^+ \nu_e \mu^- \bar{\nu}_\mu b \bar{b} j + X$, including for the first time the full off-shell effects for top quarks and W bosons: double-, single- and non-resonant contributions at the order {\cal{O}}(\alpha_{s}^4 \alpha^4). Focusing on the case of the LHC at 8 TeV, we analyse numerical re ... More
Presented by Dr. Giuseppe BEVILACQUA on 13 Apr 2016 at 12:00 PM
Session: Plenary
Presented by Dr. Olaf BEHNKE on 11 Apr 2016 at 9:00 AM
Session: WG6 Spin Physics
Track: Spin Physics
The Deep Inelastic Scattering (DIS) proved to be a great tool in testing the theory of strong interactions, which was a major focus in last decades. Semi-Inclusive DIS (SIDIS), with detection of an additional hadron, allowed first studies of 3D structure of the nucleon, moving the main focus from testing the QCD to understanding of strong interactions and quark-gluon dynamics to address a numbe ... More
Presented by Harut AVAGYAN on 12 Apr 2016 at 12:00 PM
Session: WG4/WG5 joint session (HF+diffraction)
Track: Small-x, Diffraction and Vector Mesons
Measurements of open charm production are presented in diffractive deep inelastic scattering (5 < Q2 < 100 GeV2), based on HERA data recorded at √s = 319 GeV with an integrated luminosity of 281 pb-1. The event topology is given by ep → eXY, where the system X, containing at least one D(2010) meson, is separated from a leading low-mass proton dissociative system Y by a large rapidity gap. The ... More
Presented by Karel CERNY on 13 Apr 2016 at 5:50 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We study the inclusive DDbar and DD pair production in proton-proton collisions at the LHC at leading order of the parton Reggeization approach endowed with universal scale-depended fragmentation functions for c-quark to D-meson and for gluon to D-meson transitions. We have described DDbar and DD correlations in azimuthal angle, as well as transverse momentum, rapidity, and invariant mass distribu ... More
Presented by Mr. Anton KARPISHKOV on 12 Apr 2016 at 9:00 AM
Session: Plenary
Presented by Prof. Helmut DOSCH on 11 Apr 2016 at 10:30 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
At the LHC dark matter particles can be produced in association with other particles which mainly come from initial state radiation. Searches for such processes are presented using events with jets, photons or massive gauge bosons recoiling against large missing transverse momentum in ATLAS at 13 TeV. These “mono-X” signatures provide powerful probes to dark matter production at the LHC, ... More
Presented by Emma Elizabeth TOLLEY on 13 Apr 2016 at 11:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We determine the mass of the top quark from cross section data for the hadro-production of single top quarks in the $t$- and $s$-channel reactions. We apply QCD perturbative corrections up to next-to-next-to-leading order terms from soft-gluon resummation to extract the top-quark mass in well-defined renormalization schemes. The cross section for the production of single top quarks is dominated by ... More
Presented by Dr. Stephan THIER on 13 Apr 2016 at 12:20 PM
Session: WG4/WG5 joint session (HF+diffraction)
Track: Small-x, Diffraction and Vector Mesons
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 ̄c and b ̄b pair production are calculated in the framework of the Ingelman-Schlein model corrected for absorption effects. In this approach one assumes that the pomeron has a well defined partonic structure, and that the hard proc ... More
Presented by Dr. Marta LUSZCZAK on 13 Apr 2016 at 4:30 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
I analyse, within a dipole model, the inclusive DIS cross section data, obtained from the last HERA measurements (2015). I show that these high precision data are very well described within the dipole model framework, which is complemented with a valence quark structure functions. I also discuss the role of higher twist corrections to the standard PDFs fit. This analysis I have done in collab ... More
Presented by Dr. Agnieszka LUSZCZAK, Dr. Agnieszka LUSZCZAK, agnieszka LUSZCZAK on 12 Apr 2016 at 10:00 AM
on 12 Apr 2016 at 12:40 PM
on 13 Apr 2016 at 10:20 AM
Session: WG7 Future Experiments
Track: Future Experiments
The deep inelastic scattering (DIS) cross section for scattering from bound nucleons differs from that of free nucleons. This experimental phenomena, known as the EMC effect, was first discovered 30 years ago and still lack an accepted theoretical explanation. In recent years it became accepted that any explanation to the EMC must include modification of the bound nucleon structure function due to ... More
Presented by Or HEN on 14 Apr 2016 at 11:46 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Pseudorapidity and transverse momentum distributions of charged-particles produced in pp collisions at 13 TeV will be presented for different event categories: an inclusive, inelastic enhanced, SD enhanced and NSD enhanced event samples. The measurements are compared to MC predictions tuned to describe the Underlying Event properties at 7 TeV.
Presented by Mr. Juan Manuel GRADOS LUYANDO on 14 Apr 2016 at 12:20 PM
on 12 Apr 2016 at 10:20 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
We study both the single and double parton scattering contributions to 4 jet production in kt-factorization using off-shell matrix elements and KMR PDFs. We compare them to the collinear case and find that the expected relevance of the Double Parton Scattering contribution is tamed in the kt-factorization framework: in particular, kinematic cuts should be chosen carefully as we thoroughly discuss.
Presented by Dr. Mirko SERINO on 14 Apr 2016 at 11:24 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
Multi parton distribution functions (MPDs) are interesting in view of the study of Multi Parton Interactions in hadron-hadron collisions. We use the Stirgling-Gaunt sum rules to construct explicitly an initial condition for the double gluon distribution function starting from the known MSTW form of the single gluon distribution function. The result is parameter free. We also consider the evoluti ... More
Presented by Mirko SERINO on 13 Apr 2016 at 10:00 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
We use a sample of diphoton + dijet events collected using the D0 detector at the Fermilab Tevatron Collider to measure the effective cross section of double parton interactions in proton-antiproton collisions at √s=1.96 TeV. We also study the simultaneous production of two heavy quarkonia (two J/ψ or J/ψ and Υ) to extract the effective cross section of double parton interactions. We repo ... More
Presented by Mr. Iain BERTRAM on 14 Apr 2016 at 12:36 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The double parton scattering (DPS) in proton-proton collisions at a center-of-mass energy of 8 TeV has been investigated using various final states. Multi-Jet, including b-jets, photon-jets as well as same-sign W bosons with each W boson decaying into muon and associated neutrino. The observables most sensitive to double parton scattering are defined and studied. A multivariate analysis is develop ... More
Presented by Gilvan Augusto ALVES on 14 Apr 2016 at 11:00 AM
Session: WG7 Future Experiments
Track: Future Experiments
Polarized beams will play a crucial role in the physics program planned for future electron-ion colliders. The large luminosities available at these facilities imply excellent statistical precision; hence it is important to have comparable precision in the experimental systematic uncertainties. Knowledge of the polarization of the electron and ion beams is one such key systematic uncertainty. ... More
Presented by Dr. Dave GASKELL on 14 Apr 2016 at 12:09 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
A search for electroweak production of supersymmetric particles is performed with two tau leptons in the final state. These results are based on 18.1 to 19.6 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}$ = 8\TeV collected with the CMS detector at the CERN Large Hadron Collider. The observed events are found to be consistent with the standard model prediction. Upper limits are set on the mass ... More
Presented by Hamed BAKHSHIANSOHI on 12 Apr 2016 at 12:20 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The production of single W and Z bosons with two jets at high invariant mass has been studied by the ATLAS collaboration in detail using data corresponding to 20.3 /fb at a centre-of-mass energy of 8 TeV. Integrated and differential cross sections are measured in many different phase space regions with varying degree of sensitivity to the electroweak production in vector boson fusion. The cross se ... More
Presented by Mr. Christian GUMPERT on 12 Apr 2016 at 5:10 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
A first measurement is presented of exclusive photoproduction of &rho;0 mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years 2006 and 2007 at a centre-of-mass energy of &radic;=319 GeV and correspond to an integrated luminosity of 1.16 pb-1. The &rho;0 mesons with transverse momenta p_T&lt;1 GeV are reconstructed from their decays to charged pion ... More
Presented by Dr. Sergey LEVONIAN on 12 Apr 2016 at 12:00 PM
Session: WG6 Spin Physics
Track: Spin Physics
An extensive experimental program with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab has been under way to study the 3-dimensional structure of the nucleon through investigating Generalized Parton Distributions (GPDs) by measuring hard exclusive processes such as deeply virtual Compton scattering (DVCS) and deeply virtual meson production (DVMP). The GPDs provide a route to spati ... More
Presented by Kyungseon JOO on 13 Apr 2016 at 5:00 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We discuss the potential to constrain the small-x PDFs using the exclusive production of heavy vector mesons. The calculation of J/psi and Upsilon photoproduction at NLO in collinear factorisation is described. The different behaviour of the NLO corrections for J/psi and Upsilon is highlighted and we outline what might be expected from the inclusion of these processes in a PDF fit.
Presented by Dr. Stephen JONES on 14 Apr 2016 at 12:00 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We discuss exclusive central diffractive dipion production in the reactions $pp \to pp \pi^{+} \pi^{-}$ and $p\bar{p} \to p\bar{p} \pi^{+} \pi^{-}$ at high energies. The calculation is based on a tensor pomeron model and the amplitudes for the processes are formulated in an effective field-theoretic approach [1]. We include the purely diffractive dipion continuum, and the scalar and tensor resonan ... More
Presented by Dr. Piotr LEBIEDOWICZ on 12 Apr 2016 at 5:30 PM
Session: WG6 Spin Physics
Track: Spin Physics
The HERMES experiment has extensively studied exclusive meson production in deep-inelastic scattering of the 27.6 GeV electron/positron beam of HERA by various gaseous targets internal to the storage ring. Recent results on exclusive omega production are presented: spin-density matrix elements using unpolarized and longitudinally polarized leptons and unpolarized hydrogen and deuterium targets, an ... More
Presented by Sergey MANAENKOV on 13 Apr 2016 at 5:40 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We report a measurement of exclusive pion pair production in proton-proton collisions, dominated by $p + p \rightarrow p^{(*)} + \pi^{+} \pi^{-} + p^{(*)}$, where the $\pi^{+} \pi^{-}$ pair is produced at central rapidities $y$ and the incident protons stay intact or dissociate without being detected. The measurement is performed with the CMS detector at the LHC, using an integrated luminosity of ... More
Presented by Mohsen KHAKZAD on 12 Apr 2016 at 5:10 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Exclusive W+ W- pair production in photon-photon collisions during the pp runs at 7 and 8TeV are observed and used to put constraints on the Anomalous Quartic Gauge Couplings. During the proton lead collisions in photon-induced vector meson production is observed via the decay of Ypsilon into two muons. The slope of the squared pT distribution is measured to determine the size of the production re ... More
Presented by Ruchi CHUDASAMA on 12 Apr 2016 at 4:30 PM
Session: WG6 Spin Physics
Track: Spin Physics
Generalized Parton Distributions (GPDs) are nowadays the object of an intense effort of research, in the perspective of understanding nucleon structure. They describe the correlations between the longitudinal momentum and the transverse spatial position of the partons inside the nucleon and they can give access to the contribution of the orbital momentum of the quarks to the nucleon spin. Deeply V ... More
Presented by Silvia NICCOLAI on 13 Apr 2016 at 4:30 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The anomalous $HZ\gamma$ couplings, which are dominated by the new physics effects, through the process $pp\rightarrow p\gamma p\rightarrow p H X$ at the LHC are studied. To this purpose, an effective Lagrangian, in a model independent approach, with dimension six operators is considered in this paper. New interaction terms regarding beyond the standard model physics include the Higgs particle ano ... More
Presented by Dr. Sara TAHERI MONFARED on 13 Apr 2016 at 5:10 PM
Session: WG6 Spin Physics
Track: Spin Physics
Spin and transverse momentum dependent parton distributions - GPDs, TMDs and GTMDs - are at the interface between the non-perturbative regime of QCD hadron structure and observable quantities. The distributions appear as linear superpositions and convolutions within helicity amplitudes for parton-nucleon scattering processes, which, in turn, occur in amplitudes for leptoproduction processes. The p ... More
Presented by Prof. Gary GOLDSTEIN on 14 Apr 2016 at 11:30 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Exclusive 0-jet processes at hadron colliders are nowadays studied at an unprecedented precision in theory and experiment. Within the framework of Soft-Collinear Effective Theory we discuss how to incorporate massive bottom quark effects in the resummed cross section for Drell-Yan, where as specific examples for a measured exclusive observable we consider the transverse momentum of the electroweak ... More
Presented by Piotr PIETRULEWICZ on 13 Apr 2016 at 11:30 AM
Session: WG6 Spin Physics
Track: Spin Physics
The COMPASS experiment at CERN SPS has taken data with a polarised muon beam scattering off a polarised LiD target from 2002-2004. The same measurement was also performed in 2006 increasing the statistics by roughly a factor of two. The new results from 2006 data on the longitudinal double spin asymmetry A_1^d on the spin dependent structure function g_1^d will be shown and compared to the previo ... More
Presented by Mr. Malte WILFERT on 13 Apr 2016 at 11:00 AM
Session: WG1/WG3 joint session (EW+PDF)
Track: Electroweak Physics and Beyond the Standard Model
Using inclusive DIS cross sections measured with the H1 experiment at HERA, electroweak parameters of the Standard Model are probed. The cross sections were determined using longitudinally polarized lepton beams, which enhances the sensitivity to the vector couplings of the light quarks. The quark couplings and the electroweak mixing angle are probed through the γ/Z interference. This gives acces ... More
Presented by Daniel BRITZGER on 13 Apr 2016 at 3:00 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Forward $J/\psi$ production and suppression in high energy proton-nucleus collisions can be an important probe of gluon saturation. We study this process in the Color Glass Condensate framework and show that using the Glauber approach to extrapolate the dipole cross section of a proton to a nucleus leads to results closer to experimental data than previous calculations in this framework. We also i ... More
Presented by Dr. Bertrand DUCLOUE on 13 Apr 2016 at 9:20 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The forward (HF) and very-forward (CASTOR) calorimeters of CMS are used to measure the density of energy per unit of pseudorapiditdy up to eta of 6.6 at 13TeV. The measurements are compared to model predictions. Furthermore, the corresponding data of transverse energy are compared to CMS measurements at lower center-of-mass energies, where all data are shifted by the beam rapidity. The result is a ... More
Presented by Igor KATKOV on 14 Apr 2016 at 9:20 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We discuss Drell-Yan production of dileptons at high energies in forward rapidity region in a hybrid high-energy approach which uses unintegrated gluon distributions in one proton and collinear quark/antiquark distributions in the second proton. Corresponding momentum-space formula for the differential cross sections in high-energy approximation has been derived and will be presented. The ... More
Presented by Prof. Antoni SZCZUREK, Wolfgang SCHAFER on 14 Apr 2016 at 9:40 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
With the ever increasing amount of precise data available for hadron production processes, the perturbative QCD framework is being extended to explore effects and corrections that go beyond the next-to-leading order (NLO) accuracy. Fixed order calculations at next-to-next-to-leading order (NNLO) are becoming the new necessary standard required for precision predictions and, consequently, the analy ... More
Presented by Mr. Daniele Paolo ANDERLE on 12 Apr 2016 at 3:37 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We investigate different methods to incorporate the effect of photons in hard processes. We compare two different approaches used for calculating cross sections for two-photon $p p \to l^+ l^- X$ process. In one of the approaches photon is treated as a collinear parton in the proton. In the second approach recently proposed a $k_t$-factorization method is used. We discuss how results of ... More
Presented by Prof. Antoni SZCZUREK on 14 Apr 2016 at 11:20 AM
Session: Plenary
Track: Future Experiments
Presented by Claire GWENLAN, Dr. Wally MELNITCHOUK, Dr. Elke-Caroline ASCHENAUER on 15 Apr 2016 at 2:50 PM
Session: WG6 Spin Physics
Track: Spin Physics
We investigate the gluon transverse momentum dependent correlators as Fourier transform of matrix elements of nonlocal operator combinations. At the operator level these correlators include both field strength operators and gauge links bridging the nonlocality. In contrast to the collinear PDFs, the gauge links are no longer unique for transverse momentum dependent PDFs (TMDs) and also Wilson loop ... More
Presented by Piet MULDERS on 12 Apr 2016 at 9:00 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Review of hadronisation models.
on 12 Apr 2016 at 8:45 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
The available statistics of heavy flavored particles collected at the LHC in pp collisions at 7, 8 and 13 TeV provides an excellent opportunity to test the standard model and probe for new physics effects. A review of selected recent measurements on heavy flavors (production and propeties, rare decays, CP violation, exotic and standard quarkonia) by CMS based on LHC Run I and Run II data is presen ... More
Presented by Prof. Kai-Feng CHEN on 12 Apr 2016 at 2:50 PM
Session: Plenary
Presented by Sandra KORTNER on 11 Apr 2016 at 5:00 PM
Session: WG7 Future Experiments
Track: Future Experiments
In this talk, we review the possibilities for Higgs studies at the LHeC and the FCC-he. Specifically, we will show recent results on the determination of the $H\to b \bar b$ coupling, and on the progress in the $H\to c \bar c$. We will then discuss the possibility to study at LHeC the coupling of Higgs to the 'dark sector. The final topic is HH production at FCC-he and the sensitivity to anomalous ... More
Presented by Olaf BEHNKE on 12 Apr 2016 at 5:21 PM
Session: WG7 Future Experiments
Track: Future Experiments
Run-I at the LHC was very successful with the discovery of a new boson with properties compatible with those of the Higgs boson predicted by Standard Model. Precise measurements of the boson properties, and the discovery of physics beyond the Standard Model, are primary goals of the just restarted LHC running at 13 TeV collision energy and all future running at the LHC. The physics prospects w ... More
Presented by Magdalena SLAWINSKA on 14 Apr 2016 at 9:46 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
Charm quark distribution function play an important role in study of many presses. In the standard global analysis of parton distribution functions, charm quark distribution arises perturbatively by gluon splitting. Nonetheless, existence of a non-perturbative intrinsic charm quark component in the nucleon is predicted by QCD. We present some phenomenological light cone models for non-perturbative ... More
Presented by Saeedeh ROSTAMI on 14 Apr 2016 at 12:20 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
As the energy of the LHC increases, the heavy quarks play a more significant role. We examine both the impact of the heavy quarks on the predictions for processes such as boson production (both with and without an associated heavy quark), and consider methods to constrain the heavy quark PDFs.
Presented by Prof. Fred OLNESS on 12 Apr 2016 at 5:30 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The color dipole formalism is extended to the study of exclusive processes associated with a leading neutron in ep collisions at high energies. We discuss the leading neutron production in $e + p \rightarrow e + n + X$ collisions at high energies and estimate the related observables, which were measured at HERA and may be analysed in future electron-proton ($ep$) colliders. We show that the recen ... More
Presented by Prof. Victor Paulo GONCALVES on 12 Apr 2016 at 12:20 PM
Session: WG6 Spin Physics
Track: Spin Physics
Inclusive cross sections and azimuthal asymmetries were extracted from e+e− annihilation data collected with the Belle detector. These data were taken at the KEKB e+e− collider at a center-of-mass energy of around sqrt(s) = 10.58 GeV. The cross sections for single-hadron and hadron-pair production provide very clean information on the spin-independent fragmentation functions, which describ ... More
Presented by Ms. Charlotte VAN HULSE on 12 Apr 2016 at 5:50 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
In this talk a study of differential cross sections for the production of four jets in multi-Regge kinematics will be presented, the main focus lying on azimuthal angle dependences. The theoretical setup consists in the jet production from a single BFKL ladder with a convolution of three BFKL Green functions, where two forward/backward jets are always tagged in the final state. Furthermore, the ta ... More
Presented by Mr. Francesco Giovanni CELIBERTO on 12 Apr 2016 at 2:50 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
First, we define new observables sensitive to BFKL dynamics in the context of multijet production at the Large Hadron Collider. We propose the study of the inclusive production of three jets well separated in rapidity from each other, with two of them being very forward. We show that the tagging of a third jet in the central region of rapidity allows for a very strong test of the BFKL formalism. W ... More
Presented by Dr. Grigorios CHACHAMIS on 12 Apr 2016 at 3:10 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Exclusive vector meson production can be used to directly probe the gluon density of a hadron. Measuring the cross section differentially in the momentum transfer t makes it possible to determine the transverse density profile (via coherent diffraction) and density fluctuations (incoherent diffraction) of the target hadron. This knowledge on the geometric fluctuations of the proton is particularly ... More
Presented by Dr. Heikki MÄNTYSAARI on 12 Apr 2016 at 11:00 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
We discuss a scenario in which the enhancement in the diphoton final state at $M_{\gamma \gamma}$ = 750 GeV, recently observed by the ATLAS and CMS collaborations, is a technipion. We consider two different detailed minimal scenarios. In a first one (vector-like technicolor model) we assume that the vector-boson fusion is a dominant production mechanism. In a second one (one family walkin ... More
Presented by Prof. Antoni SZCZUREK on 13 Apr 2016 at 4:30 PM
Session: WG6 Spin Physics
Track: Spin Physics
We present a comprehensive new global QCD analysis of polarized inclusive deep-inelastic scattering, including the latest high-precision data on longitudinal and transverse polarization asymmetries from Jefferson Lab and elsewhere. The analysis is performed using a new iterative Monte Carlo fitting technique which generates stable fits to polarized parton distribution functions (PDFs) with statist ... More
Presented by nobuo SATO on 13 Apr 2016 at 9:50 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
In 2010, the STAR Collaboration collected a large sample of triggers for ultra-peripheral AuAu collisions. In this talk, I will present measurements from this sample of J/Psi production in association with neutrons from photonuclear breakup. Preliminary results for the cross section as a function rapidity and pT will be presented and compared to models; the large component at low pT demonstra ... More
Presented by Dr. William SCHMIDKE on 13 Apr 2016 at 2:30 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
New measurements of prompt and non-prompt J/psi and of Upsilon production at a centre-of mass energy of 13 TeV are presented. Comparisons with theoretical predictions and precision measurements made at energies of 2.76, 7 and 8 TeV are discussed.
Presented by Susan CHEATHAM on 14 Apr 2016 at 10:00 AM
Session: WG7 Future Experiments
Track: Future Experiments
The Electron-Ion Collider (EIC) is envisioned as the next-generation U.S. facility to study quarks and gluons in strongly interacting matter. The broad physics program of the EIC aims to precisely image gluons in nucleons and nuclei and to reveal the origin of the nucleon spin by colliding polarized electrons with polarized protons, polarized light ions, and heavy nuclei at high luminosity. Th ... More
Presented by Dr. Rik YOSHIDA on 13 Apr 2016 at 11:46 AM
Session: WG7 Future Experiments
Track: Future Experiments
The new NSAC Long Range Plan endorses construction of a high energy high luminosity polarized electron-ion collider in US for reaching new QCD frontier. JLEIC, a Jefferson Lab ring-ring design of electron-ion collider based on the CEBAF recirculating linac, will enable collisions of electrons with energy up to 10 GeV and either protons with energy up to 100 GeV, or heavy ions with energy up to 40 ... More
Presented by Dr. Yuhong ZHANG on 13 Apr 2016 at 9:23 AM
Session: WG1/WG2 joint session (QCD and PDF)
Track: QCD and Hadronic Final States
The production of inclusive jets as well as of dijet and trijet topologies is investigated at HERA in the domain of low momentum transfer Q2 &lt; 100 GeV2, using the H1 experiment. The new data complement a previous measurement done at higher momentum transfer. The value of the strong coupling constant &alpha;_s(M_Z) is extracted and its running is probed.
Presented by Daniel BRITZGER on 12 Apr 2016 at 4:30 PM
Session: WG1/WG2 joint session (QCD and PDF)
Track: QCD and Hadronic Final States
We present recent jets results from CMS at at 2.76, 7 and 8 TeV and show comparison to theory calculations. Inclusive jet cross sections as well as azimuthal correlations between jets are presented.
Presented by Mr. Paolo GUNNELLINI on 12 Apr 2016 at 4:55 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Jets provide a powerful tool for probing the dynamics of the quark-gluon plasma created in Pb+Pb collisions at the LHC. The modification of high-pT jets as they propagate in the quark-gluon plasma provides insight on structure of the plasma at short-length scale. Such modifications have been observed in a variety of measurements of single jet, dijet, photon-jet and charged-particle fragmentation f ... More
Presented by Dr. Helena SANTOS on 12 Apr 2016 at 11:00 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We will discuss diphoton semi(exclusive) production in ultraperipheral $PbPb$ collisions at energy of $\sqrt{s_{NN}}=$ 5.5 TeV (LHC). The calculation is based on equivalent photon approximation in the impact parameter space. The cross sections for elementary $\gamma \gamma \to \gamma \gamma$ subprocess are calculated including two different mechanisms: \begin{itemize} \item box diagrams w ... More
Presented by Dr. Mariola KLUSEK-GAWENDA on 13 Apr 2016 at 9:00 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The high precision HERA combined measurement of inclusive deep inelastic cross sections in neutral and charged current ep scattering, corresponding to a luminosity of about 1 fb-1, permits searches for new contributions to electron-quark scattering beyond the Standard Model up to TeV scales. A new approach to beyond the Standard Model analysis of the inclusive ep data is presented; simulatan ... More
Presented by Mr. Oleksii TURKOT on 14 Apr 2016 at 9:40 AM
Session: WG6 Spin Physics
Track: Spin Physics
We derive a complete set of relations among twist-3 distribution and fragmentation functions based on the QCD equation-of-motion and identities among nonlocal operators which fully incorporate the constraints from Lorentz invariance. We show that the dynamical twist-3 functions constitute a complete set of twist-3 functions and other types of twist-3 functions can be expressed in terms of the dyn ... More
Presented by Prof. Yuji KOIKE on 12 Apr 2016 at 4:30 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The BABAR Collaboration has an intensive program  studying hadronic cross sections at low-energy e+e- annihilation, accessible via initial-state radiation. Our measurements allow significant improvements in the precision of the predicted value of the muon anomalous magnetic moment. These improvements are necessary for shedding light on the current ~3 sigma difference between the predicted and the ... More
Presented by Denis BERNARD on 14 Apr 2016 at 10:00 AM
Session: Plenary
Presented by Laurent FAVART on 11 Apr 2016 at 12:20 PM
Session: Plenary
Track: Small-x, Diffraction and Vector Mesons
Presented by Dr. Alessia BRUNI, Dr. Rainer SCHICKER, Leszek MOTYKA on 15 Apr 2016 at 12:30 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The inelastic hadronic cross section is measured at 13TeV with the CMS experiment. Different detectors are used to study the dependence on the proton momentum loss, xi. The result is given in different visible acceptance regions as well as extrapolated to the full acceptance.
Presented by Dr. Hans VAN HAEVERMAET on 14 Apr 2016 at 11:40 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The production of multi-jet final states at hadron colliders probes pQCD at several mass scales. The processes can also be used to probe the gluon density function of the proton. The ATLAS collaboration has measured the production of 4-jets final states in in 20.3 /fb of data collected at a center-of-mass energy of 8TeV. The measurements have been performed differentially as a function of a v ... More
Presented by Melissa RIDEL on 13 Apr 2016 at 3:40 PM
Session: WG6 Spin Physics
Track: Spin Physics
In 2015 the first collisions between polarized protons and nuclei occurred at the Relativistic Heavy Ion Collider (RHIC), at a center-of-mass energy of $\sqrt{s_{NN}}=200$ GeV. Comparisons between spin asymmetries and cross-sections in $p+p$ production to those in $p+A$ production provide insight into nuclear structure, namely nuclear modification factors, nuclear dependence of spin asymmetries, a ... More
Presented by Mr. Christopher DILKS on 12 Apr 2016 at 11:20 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has performed measurements of integrated and differential cross sections of the production of WW and WZ pairs in bot ... More
Presented by Mr. Felix SOCHER on 12 Apr 2016 at 4:30 PM
Session: WG6 Spin Physics
Track: Spin Physics
One of the main goals of the RHIC spin program is the determination of the gluon helicity contribution to the proton spin. This can be accessed by measuring double spin asymmetries ($A_{LL}$) of pion production at mid-rapidity in longitudinally polarized proton collisions with the PHENIX experiment. The ordering of the asymmetries with the charge of the final state pions can in addition directly i ... More
Presented by Ralf SEIDL on 13 Apr 2016 at 11:40 AM
Session: WG1/WG7 joint session (PDF+future exp.)
Track: Future Experiments
Direct photon production at forward rapidity is a promising probe for the gluon content of protons and nuclei at small x. In particular, the measurement of the nuclear modification factor for direct photons in p–A collisions at the LHC should provide a crucial test for gluon saturation. We discuss the unique role of such a photon measurement in the context of other measurements at the LHC and al ... More
Presented by Prof. Thomas PEITZMANN on 12 Apr 2016 at 2:28 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The average charge and the multiplicity of charged hadrons within a jet provide new insights into the modeling of strong interactions. The jet charge can also be used to tag hadronically decaying gauge bosons and the number of charged particles within a jet provides a powerful means to distinguish gluon-initiated from quark-initiated jets. The ATLAS collaboration has used a selection of di-jet ev ... More
Presented by Pierre-Hugues BEAUCHEMIN on 13 Apr 2016 at 5:50 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the gluon density function of the proton. The ATLAS collaboration has performed precise measurements of the inclusive production of isolated prompt photons in 20.3 /fb of data collected at a center-of-mass energy of 8TeV and in 3.2 /fb of data collected at a center ... More
Presented by Juan TERRON on 12 Apr 2016 at 11:48 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has measured inclusive and differential cross sections of the production of ZZ pairs and Z and photon pairs, using ... More
Presented by Stamatios GKAITATZIS on 12 Apr 2016 at 4:50 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The exclusive deep inelastic electroproduction of psi(2S) and J/\psi(1S) at an ep centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range 2 < Q2 < 80 GeV2, 30 < W < 210 GeV and |t| < 1 GeV2, where Q2 is the photon virtuality, W is the photon--proton centre-of-mass energy and t is the squared four-momentum transfer at the proton vertex. The data ... More
Presented by Ms. Nataliia KOVALCHUK on 12 Apr 2016 at 11:20 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
ATLAS measurement of azimuthal correlations between particle pairs at large pseudorapidity separation in pp and pPb collisions are presented. The data were collected using a combination of the minimum-bias and high track-multiplicity triggers. A detailed study of the dependence of two-particle correlations on the charged particle multiplicity, transverse momentum of the pair constituents and the p ... More
Presented by Klaudia BURKA on 12 Apr 2016 at 9:40 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The measurements of the underlying events (UE) in the event topology of leading jet and leading track are presented. UE activities are quantified in term of particle and energy density. The UE observables are calculated in the transverse region with respect to the direction highest pT jet/track. These UE observables are measured as a as function of the pT of the leading track and jet.
Presented by Prof. Ada SOLANO on 14 Apr 2016 at 9:15 AM
Session: WG2/WG3 joint session (QCD+EW)
Track: Electroweak Physics and Beyond the Standard Model
The production of jets in association with vector bosons is an important process to study QCD in a multi-scale environment. The ATLAS collaboration has performed a first measurement of vector boson+jets cross sections, differential in several kinematic variables, in 3.2 /fb of proton-proton collision data taken in 2015 at center-of-mass energies of 13TeV. In data corresponding to 20.3 /fb at a ... More
Presented by Mrs. Marisa SANDHOFF on 13 Apr 2016 at 9:50 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Most recent results on CP violation searches in the charm sector are presented. These include the world’s most precise measurements of direct and indirect CP asymmetries in the singly-Cabibbo-suppressed modes D0->pipi and D0->KK, based on the 3/fb data sample collected by LHCb during Run I.
Presented by Mr. Pietro MARINO on 12 Apr 2016 at 10:00 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
A measurement of the decorrelation of azimuthal angles between the two jets with the largest transverse momenta is presented for seven regions of leading jet transverse momentum up to 2.2 TeV. The results are compared to fixed-order predictions of perturbative quantum chromodynamics (QCD), and to simulations using Monte Carlo event generators that include parton showers, hadronization, and multipa ... More
Presented by Panos KOKKAS on 13 Apr 2016 at 5:25 PM
Session: WG1/WG3 joint session (EW+PDF)
Track: Structure Functions and Parton Densities
Precision measurements of the Drell-Yan production of W and Z bosons at the LHC provide a benchmark of our understanding of perturbative QCD and electroweak processes and probe the proton structure in a unique way. The ATLAS collaboration has performed these measurements at a center-of-mass energy of 13 TeV. Ratios of W and Z cross sections and of the W boson charges significantly reduce experi ... More
Presented by Dr. Hayk PIRUMOV on 13 Apr 2016 at 2:45 PM
Session: WG1/WG3 joint session (EW+PDF)
Track: Structure Functions and Parton Densities
Precision measurements of the Drell-Yan production of W and Z/gamma* bosons at the LHC provide a benchmark of our understanding of perturbative QCD and probe the proton structure in a unique way. The ATLAS collaboration has performed high precision measurements at center-of-mass energies of 7TeV and 8TeV, integrated and as a function of the rapidity and the Z/gamma* mass. New measurements at 7 Te ... More
Presented by Elena YATSENKO on 13 Apr 2016 at 2:30 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Inclusive charged-particle measurements at hadron colliders probe the low-energy non-perturbative region of QCD. The ATLAS collaboration has measured the charged-particle multiplicity and its dependence on transverse momentum and pseudorapidity in special data sets with low LHC beam currents, recorded at center-of-mass energies of 8TeV and 13TeV. The new precise measurements at 8 TeV cover a wide ... More
Presented by Wolfgang LUKAS on 14 Apr 2016 at 12:00 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
The latest measurements of the top quark mass using the ATLAS experiment are presented. A measurement based on a multi­dimensional template fit that can constrain the uncertainties on the energy measurements of jets is presented and combined with a measurement using dilepton events. A new measurement of the top quark mass using leptonic kinematic variables is presented. The measurement uses ... More
Presented by Michael BENDER on 13 Apr 2016 at 11:20 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Measurements of several top-quark properties are presented, obtained from the CMS data collected at various centre-of-mass energies. The results include measurements of the top pair charge asymmetry, the W helicity in top decays, the top quark charge, the ttbar spin correlation, of the top polarisation and the search for anomalous couplings. The results are compared with predictions from the stand ... More
Presented by Deniz POYRAZ on 13 Apr 2016 at 9:40 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
A correct modelling of the underlying event in proton-proton collisions is important for the proper simulation of kinematic distributions of high-energy collisions. The ATLAS collaboration extended previous studies at 7 TeV with a leading track or jet or Z boson by a new study of Drell-Yan events in 1.1 /fb of data collected at a center-of-mass energy of 7TeV. In this new study the distributions ... More
Presented by David Anthony MILSTEAD on 14 Apr 2016 at 9:40 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The total pp cross section is a fundamental property of the strong interaction which can not be calculated in perturbative QCD but only described based on phenomenological models. The ATLAS collaboration has explored the total proton-proton cross section, using measurements of the total inelastic proton-proton cross sections and of the diffractive part of the inelastic cross section in specia ... More
Presented by Maciej Marek TRZEBINSKI on 14 Apr 2016 at 11:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
The large centre­of­mass energy available at the proton­proton 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 radiation in top anti­top quark final states. Results on the top production in associ ... More
Presented by Alexander KHANOV on 13 Apr 2016 at 3:10 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Search for deviations from the standard model is performed in the systems of the neutral B mesons. The Bs system is studied in the decay into J/psi phi. The mixing phase phi_s and the width difference DeltaGamma_s are determined through the simultaneous study of angular distributions in the final state and of the decay time, performed together with flavor tagging at production. ÊThe measurement ... More
Presented by Guennadi BORISOV on 12 Apr 2016 at 11:20 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Hadronic jet production at LHC is an excellent testing ground for QCD. Essential components of QCD, necessary for the description of hadronic jet data, are hard parton radiation and multiple parton interactions. The importance of these components increases for final states including multiple jets. We will show results of one observables sensitive to the hard parton radiation, which is the azimutha ... More
Presented by Gabor VERES on 13 Apr 2016 at 3:15 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Overview of the latest legacy measurements of multibosons with CMS
Presented by Jing LI on 12 Apr 2016 at 5:30 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Early results from Run II multiboson measurements with CMS
Presented by Xavier COUBEZ on 12 Apr 2016 at 5:50 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
In this talk a short description of the soft gluon resummation for pp->ttbarH process will be given. This is the first application of the Mellin resummation technique in a 2->3 process. The absolute threshold resummation is performed up to NLL accuracy and matched to the known NLO QCD cross-section. Results for the total cross-section at the LHC and their theoretical uncertainties will be presente ... More
Presented by Mr. Tomasz STEBEL on 13 Apr 2016 at 11:55 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We present the computation for the impact factor for the production of dijets in diffractive DIS at Next-to-Leading Order using Balitsky's shockwave formalism.
Presented by Renaud BOUSSARIE on 12 Apr 2016 at 10:00 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
High-energy nuclear collisions are often classified in terms of centrality. Theoretically the centrality binning is obtained using the Woods-Saxon parametrization for nuclear density as an input for Glauber model. Traditionally the parametrization do not differentiate between protons and neutrons. However, according to measurements in nuclear physics, the density of neutrons decrease slower at the ... More
Presented by Dr. Ilkka HELENIUS on 13 Apr 2016 at 12:20 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Coloumb gluons and ordering variable.
Presented by Dr. Rene ANGELES MARTINEZ on 13 Apr 2016 at 5:00 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
In this talk, I will focus on the study of associated-quarkonium production in a number of channels at the LHC. First, I will address the case of quarkonium-pair production [1,2,3] which has recently been studied by LHCb [4], CMS [5] and D0 [6,7]. I will argue that the inclusion of Double-Parton Scattering (DPS) and Next-to-Leading Order (NLO) contributions are necessary to account for the existin ... More
Presented by Jean-Philippe LANSBERG on 14 Apr 2016 at 12:00 PM
Session: WG6 Spin Physics
Track: Spin Physics
In this talk, we discuss the new hard pole contribution to the transverse-momentum-weighted single-transverse spin asymmetry in semi-inclusive deep inelastic scattering. We perform the complete next-to-leading order calculation of the $P_{h\perp}$-weighted cross section and show that the new hard pole contribution is required in order to obtain the complete evolution equation for the Qiu-Sterman f ... More
Presented by Dr. Shinsuke YOSHIDA on 12 Apr 2016 at 9:50 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Searches for lepton number violation and resonances in the K+- -->pi mu mu decays at the NA48/2 experiment The NA48/2 experiment at CERN collected a large sample of charged kaon decays into final states with multiple charged particles in 2003-2004. A new upper limit on the rate of the lepton number violating decay K+- --> pi-+ mu+- mu+- obtained from this sample is reported: 8.6 × 10^−{11} ... More
Presented by Radoslav MARCHEVSKI on 14 Apr 2016 at 9:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Some time ago two of us predicted that at large energies relevant for the LHC the production of double charm should be dominated by the double-parton scattering (DPS) mechanism [1]. Those studies of double $c \bar c$ production was extended next to the $k_t$-factorization approach which includes effectively higher-order QCD effects [2,3]. A relatively good description of the LHCb experimental data ... More
Presented by Prof. Antoni SZCZUREK on 12 Apr 2016 at 9:20 AM
Session: WG7 Future Experiments
Track: Future Experiments
An Electron-Ion Collider (EIC) would enable next-generation measurements of DIS on light nuclei (deuteron, 3He, ...) with detection of nucleons and fragments in the forward region and measurement of their recoil momentum ("spectator tagging"). Such experiments allow one to control the nuclear configuration during the high-energy process and could be used for (a) precision measurements of neutron ... More
Presented by Wim COSYN on 13 Apr 2016 at 12:09 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The Color Glass Condensate framework has been successfully applied to many high-energy scattering processes, and it has also been seen as a powerful tool to describe initial state of heavy ion collisions. An important next step for the CGC phenomenology is to perform these calculations at next-to-leading order accuracy, which would allow a qualitative test of the saturation picture. A necessary in ... More
Presented by Dr. Heikki MÄNTYSAARI on 12 Apr 2016 at 9:40 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present a detailed study of nuclear corrections in the deuteron (D) from an analysis of existing data from Deep Inelastic Scattering (DIS) off proton and D, Drell-Yan production in pp and pD interactions, $W^\pm$ and $Z$ boson production in pp and $p \bar p$ collisions. In particular, we discuss the determination of the off-shell correction describing the modification of parton distributions (P ... More
Presented by Roberto PETTI on 13 Apr 2016 at 9:40 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present the status of our calculation of nuclear parton distribution functions on the basis of our recently developed semi-microscopic model, which takes into account a number of nuclear effects including nuclear shadowing, Fermi motion and nuclear binding, nuclear meson-exchange currents and off-shell corrections to bound nucleon distributions. We discuss in details the dependencies of nuclear ... More
Presented by Roberto PETTI, Sergey KULAGIN on 13 Apr 2016 at 12:00 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present the nCTEQ15 global analysis of nuclear parton distribution functions (nPDFs). The main addition to the previous nCTEQ analysis is the introduction of PDF uncertainties based on a modified Hessian method. Another important improvement is the inclusion of pion production data from RHIC providing additional constraints on gluon PDF. In this presentation we briefly discuss the framework of ... More
Presented by Aleksander KUSINA on 13 Apr 2016 at 11:40 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
The behaviour of parton distribution functions (PDFs) at sufficiently small and large values of momentum fractions is expected to be governed by a power law, as a result of Regge theory and spectator counting rules respectively. I investigate in which regions of momentum fraction and energy such an asymptotic behaviour emerges, based on recent determinations of PDFs from a global analysis of exper ... More
Presented by Dr. Emanuele Roberto NOCERA on 13 Apr 2016 at 6:10 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
High Energy Jets (HEJ) is a novel method for organising the resummation of high energy logs in QCD to Leading Logarithmic accuracy (LL) in multi-jet production at hadronic colliders. In this talk, I will introduce the main concepts behind the approach and show how we build our exclusive predictions. I will show important results from recent LHC jet analyses. I will then discuss how the formalis ... More
Presented by James COCKBURN on 13 Apr 2016 at 2:50 PM
Session: WG1/WG7 joint session (PDF+future exp.)
Track: Future Experiments
An update is presented on the possibilities for precision QCD studies at the LHeC and the FCC-he. Specifically, we will show recent results on the determination of nucleon PDFs with complete flavour decomposition and of the value of the strong coupling constant with per mille accuracy. The implications of such measurements on Higgs physics and on high mass BSM searches at the HL-LHC will be discu ... More
Presented by Prof. Amanda COOPER-SARKAR on 12 Apr 2016 at 2:51 PM
Session: WG1/WG2 joint session (QCD and PDF)
Track: QCD and Hadronic Final States
We present and discuss the impact of the most recent CMS data on the precision measurement of a_s and parton density functions.
Presented by Mr. Engin EREN on 12 Apr 2016 at 5:20 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We review the current status in the determination of parton distribution functions in view of the precision requirements for LHC in the run II.
Presented by Mrs. Ringaile PLACAKYTE, Mrs. Ringaile PLACAKYTE on 12 Apr 2016 at 12:20 PM
Session: Plenary
Presented by Prof. Halina ABRAMOWICZ on 15 Apr 2016 at 3:30 PM
Session: Plenary
Presented by Pavel NADOLSKY on 11 Apr 2016 at 9:10 AM
Session: WG1/WG7 joint session (PDF+future exp.)
Track: Future Experiments
We discuss the role of QCD and precision SM calculations for the physics program of a 100 TeV hadron collider. In particular, we discuss the role of parton distributions, jet and top quark production, electroweak and photon-induced corrections and global event properties at 100 TeV. This talk summarizes the Standard Model chapter of the FCC-hh Conceptual Design Report.
Presented by Juan ROJO on 12 Apr 2016 at 3:14 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Review of recent development in parton showers.
Presented by Dr. Zoltan NAGY on 13 Apr 2016 at 4:30 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Production of electroweak bosons via vector-boson fusion (VBF) is one of the main process classes to study during the run-2 phase of the LHC. Its double-DIS-like structure gives rise to the characteristic signature of two tagging jets in the forward regions of the detectors, and distinguishes it from QCD-induced processes, which exhibit much more central jet activity. VBF processes allow to study ... More
Presented by Michael RAUCH on 13 Apr 2016 at 6:15 PM
Session: WG6 Spin Physics
Track: Spin Physics
I will address the study of semi-inclusive deep inelastic scattering cross sections as functions of the transverse momentum, $q_T$. Soft gluon resummation is performed using the original Collins-Soper-Sterman (CSS) formalism or, equivalently, the improved Transverse Momentum Dependent (TMD) framework. The focus of this talk is the matching between the region where fixed order perturbative Q ... More
Presented by Dr. Mariaelena BOGLIONE on 12 Apr 2016 at 9:30 AM
Session: WG4/WG5 joint session (HF+diffraction)
Track: Small-x, Diffraction and Vector Mesons
The amplitude for $\gamma p \to V p$, where $V$ is a $J/\psi$ or $\Upsilon$ ground state or excited vector meson, is calculated in a pQCD $k_{T}$-factorization approach. We use this amplitude to predict the cross section for exclusive photoproduction of $J/\psi, psi', \Upsilon$ mesons in proton-proton collisions. Calculations are performed for a variety of unintegrated gluon distributions, ... More
Presented by Dr. Wolfgang SCHAFER on 13 Apr 2016 at 5:30 PM
Session: WG7 Future Experiments
Track: Future Experiments
The possibility of using plasma wakefield acceleration to build an electron-proton collider (VHEeP) at a centre-of-mass energy of 9 TeV was presented at the DIS2015 workshop. In this talk, the physics case is further developed, with more detailed studies at low parton momentum fractions, x, down to 10^-8. The VHEeP collider also has sensitivity to the production of leptoquarks approaching t ... More
Presented by Matthew WING on 12 Apr 2016 at 5:44 PM
Session: WG7 Future Experiments
Track: Future Experiments
In this talk several new physics opportunities at an EIC beyond the key measurements discussed in the EIC White paper (arXiv:1212.1701) will be highlighted, this includes measurements with jets, how to get access to intrinsic kT and photon structure. For all measurements first studies will be presented.
Presented by Dr. Elke-Caroline ASCHENAUER on 14 Apr 2016 at 11:00 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We examine the efficacy of pion exchange models to simultaneously describe leading neutron electroproduction at HERA and the d-bar - u-bar flavor asymmetry in the proton. A detailed chi^2 analysis of the ZEUS and H1 cross sections, when combined with constraints on the pion flux from Drell-Yan data, allows regions of applicability of one-pion exchange to be delineated. The analysis disfavors sever ... More
Presented by Dr. Wally MELNITCHOUK on 13 Apr 2016 at 12:40 PM
Session: WG6 Spin Physics
Track: Spin Physics
The COMPASS experiment at CERN has been contributing to the knowledge on the nucleon structure, and its description in terms of the Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs), accessed through the SIDIS process. In 2014/2015 the data taking was dedicated to the polarised Drell-Yan (DY) measurement with a negative pion beam and a transversely polarised proton target, as ... More
Presented by Márcia QUARESMA on 12 Apr 2016 at 3:00 PM
Session: WG2/WG3 joint session (QCD+EW)
Track: Electroweak Physics and Beyond the Standard Model
The ATLAS collaboration has performed precision measurements sensitive to the transverse momentum of the Z/gamma* bosons, both directly through the transverse momentum of the di-lepton pair and through the angular decorrelation as measured in the phi* observable. These measurements are sensitive to soft resummation effects and hard jet emissions for small and large momentum transfers, respectively ... More
Presented by Aleksei EZHILOV on 13 Apr 2016 at 9:00 AM
Session: WG6 Spin Physics
Track: Spin Physics
The production of jets in polarized proton collisions at STAR is dominated by quark-gluon and gluon-gluon scattering processes. The dijet longitudinal double-spin asymmetry (A_LL) is sensitive to the polarized parton distributions and may be used to extract information about the gluon helicity contribution (ΔG) to the spin of the proton. Previous STAR jet measurements at √s = 200 GeV show evide ... More
Presented by Suvarna RAMACHANDRAN on 13 Apr 2016 at 12:00 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We study the prospects for measuring nuclear modifications of the gluon density (gluonic EMC effect, antishadowing, shadowing) using open heavy flavor production (charm, beauty) at a future Electron-Ion Collider (EIC). Such direct measurements complement indirect studies of nuclear gluons through DGLAP evolution and could substantially advance our understanding of QCD in nuclei. Building on th ... More
Presented by Christian WEISS on 12 Apr 2016 at 6:10 PM
Session: WG6 Spin Physics
Track: Spin Physics
Transversity GPDs have yet to be experimentally unraveled. We propose to probe them by studying photoproduction of a rho meson and a photon and we give a feasibility study for this process to be measured at JLAB or by COMPASS.
Presented by Renaud BOUSSARIE on 14 Apr 2016 at 11:50 AM
Session: WG4/WG5 joint session (HF+diffraction)
Track: Heavy Flavours (Charm, Beauty and Top)
J/Psi mesons are copiously produced at the LHC. Inspired by the Mueller Navelet jet studies, we propose to consider the production of a forward J/Psi accompanied by a backward jet. We make a feasibility study for this process and we compute the leading order differential cross section for such events in the BFKL framework.
Presented by Renaud BOUSSARIE on 13 Apr 2016 at 5:10 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
In this talk we present recent progress in the NNPDF global analysis, in particular work towards an updated NNPDF3.1 release. Recent developments include the inclusion of the combined HERA data and of several new LHC and Tevatron experiments, theoretical improvements such as the FONLL GM-VFN scheme with heavy quark masses, fits with heavy quark mass variations and with intrinsic charm, and updates ... More
Presented by Dr. Juan ROJO on 12 Apr 2016 at 9:20 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We report on the current status of the ongoing calculation of 3-loop heavy flavor corrections to deep inelastic structure functions at large virtualities.
Presented by Abilio DE FREITAS on 12 Apr 2016 at 4:50 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
The BESIII experiment at the electron positron collider BEPCII in Beijing is successfully operating since 2008 and has collected large data samples in the tau-mass region, including the world’s largest data samples at the J/ψandψ(2S) resonances. In particular decays of these two resonances provide a rich and clean environment to study hadrons consisting out of light quarks and search for exot ... More
Presented by Dr. Marc PELIZAEUS on 12 Apr 2016 at 2:49 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We provide a detailed study of prompt double J/ψ production within the non-relativistic QCD (NRQCD) framework in proton-proton collisions at the LHC. We confront the recent LHC data with the results obtained at leading-order (LO) in the NRQCD framework within two approaches of the collinear factorization and the kT-factorization. We show that the LHCb data can be fairly described within the kT-fa ... More
Presented by Sergey BARANOV on 14 Apr 2016 at 11:40 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Following earlier measurements of prompt photon production in DIS, the ZEUS collaboration at HERA presents measurements of new kinematic variables. These include the azimuthal separations of the recoil electron, the outgoing photon and an accompanying jet, and the fraction of the incoming virtual photon energy that is taken by the outgoing photon and the jet.
Presented by Ms. Olena HLUSHCHENKO on 12 Apr 2016 at 12:12 PM
Session: Plenary
Track: QCD and Hadronic Final States
Presented by Frank TACKMANN, Dr. Simon PLÄTZER, Dr. Shima SHIMIZU on 15 Apr 2016 at 11:00 AM
Session: Plenary
Presented by Dr. Katharina MUELLER on 11 Apr 2016 at 11:40 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We describe a new approach to solve the coupled quark and gluon evolution DGLAP evolution equations with a Monte Carlo method. We show that this method is equivalent to other methods. We apply this method to extract quark and gluon parton densities collinear and as transverse momentum dependent (TMD) distributions using the precision HERA DIS data. The Monte Carlo method for the solution of the e ... More
Presented by Aleksandra LELEK on 14 Apr 2016 at 9:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Based on the full data set recorded with the BABAR detector at center-of-mass energies at and near the Upsilon(4S) resonance, and corresponding to an integrated luminosity of approximately 468 fb-1, we measure the D0-D0bar mixing parameters using a time-dependent amplitude analysis of the decay D0 -> pi+pi-pi0. With the same BABAR data set, we also measure the mass difference, Delta m, between th ... More
Presented by Adrian John BEVAN on 12 Apr 2016 at 11:00 AM
Session: WG6 Spin Physics
Track: Spin Physics
COMPASS is a fixed target experiment in operation at CERN since 2002 with a wide physics programme. By using either muon or hadron beams, both the study of the spin structure of the nucleon and the search of exotic states in hadron spectroscopy are performed. An important part of this programme is the study of transverse spin and momentum dependent parton distribution and fragmentation function ... More
Presented by Dr. Andrea BRESSAN on 12 Apr 2016 at 2:30 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Review of multijet merging.
Presented by Dr. Johannes BELLM on 13 Apr 2016 at 2:20 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
APFEL is a numerical code specialized for PDF fits that provides a fast and accurate solution of the DGLAP equations up to NNLO in QCD and LO in QED. In addition to PDF evolution, APFEL also provides a module that computes deep-inelastic scattering cross sections in several mass schemes up to NNLO in QCD. In this contribution I will present the most recent developments carried out in the APFE ... More
Presented by Dr. Valerio BERTONE on 13 Apr 2016 at 4:50 PM
Session: WG6 Spin Physics
Track: Spin Physics
The exact decomposition of the proton spin has been a much debated topic, on the experimental as well as the theoretical side. In this talk we would like to report on recent non-perturbative results and ongoing efforts to explore the proton spin from lattice QCD. We present results for several form factors from gauge field ensembles that feature a physical value of the pion mass. These form factor ... More
Presented by Mr. Christian WIESE on 14 Apr 2016 at 12:10 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Neutral pion form factor measurement by the NA62 experiment The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from ~1 m ... More
Presented by Riccardo ALIBERTI on 14 Apr 2016 at 9:20 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
This talk will report on four measurement recently completed by ATLAS: (a) the decay of Lambda_b into Lambda and psi(2S), observed for the first time and compared to the decay into Lambda and J/psi; (b) the decay of Bc into J/psi Ds and J/psi Ds*, including the first polarisation measurement for the latter channel; (c) the measurement of the ratio of the fragmentation fraction f_s/f_d, which co ... More
Presented by Artem MAEVSKIY on 12 Apr 2016 at 3:10 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Precision measurements of the Bc mass, lifetime and relative production cross-section, and the observation of several new decay modes were achieved using the 3 fb-1 of data collected by the LHCb experiment during the first run of the LHC. These results provide useful input for QCD effective models.
Presented by Dr. Hang YIN on 12 Apr 2016 at 12:40 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
In this talk the relation between heavy quark masses defined in the on-shell and $\overline{\rm MS}$ scheme is discussed at four-loop order in QCD. Special emphasis is put on the top quark mass where the four-loop result is used to estimate the remaining renormalon uncertainty. The relation between the $\overline{\rm MS}$ and on-shell mass can also be used to establish precise relations betwe ... More
Presented by Prof. Matthias STEINHAUSER on 13 Apr 2016 at 11:00 AM
Session: Plenary
Presented by Prof. Aharon LEVY on 15 Apr 2016 at 4:10 PM
Session: Plenary
Presented by Dr. Olaf BEHNKE on 15 Apr 2016 at 4:25 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
A Regge pole model for Pomeron-Pomeron total cross section in the resonance region $\sqrt{M^2}\le$ 5 GeV is presented. The cross section is saturated by direct-channel contributions from the Pomeron as well as from two different $f$ trajectories, accompanied by the isolated f$_0(500)$ resonance dominating the $\sqrt{M^{2}}\leq 1$ GeV region. A slowly varying background is taken into account. The c ... More
Presented by Dr. Rainer SCHICKER on 12 Apr 2016 at 5:50 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The successful combined data taking of the CMS and TOTEM experiments allows to characterize hadronic final states of an extremely wide pseudo-rapidity range. The measurement of the charged particles distributions over |eta<6.6| is a very important example that puts strong constraints on interaction models.
Presented by Sercan SEN on 14 Apr 2016 at 12:40 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We present the results of radiative and annihilation penguin $B(B_{s})$ decays at Belle. The $b\rightarrow s (d)\gamma$ processes are sensitive to physics beyond the Standard Model as new heavy particles can enter the loop and change the branching fractions and/or the kinematic variables. We report the results of fully inclusive $B\rightarrow X_{s,d}\gamma$ decay with both leptonic tagging and had ... More
Presented by Dr. Deepanwita DUTTA on 12 Apr 2016 at 11:40 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
I will discuss the inclusion in PDF fits of two resummations in QCD: threshold (large x) and high-energy (small x). I will present published results for threshold resummation on a global NNPDF, and implication for phenomenology (as well as future plans). I will then show preliminary results on the effect of resumming small-x logarithms in PDF fits, again in the context of the NNPDF methodology.
Presented by Dr. Marco BONVINI on 13 Apr 2016 at 4:30 PM
Session: WG7 Future Experiments
Track: Future Experiments
SHIP is a new general purpose fixed target facility, whose Technical Proposal has been recently reviewed by the CERN SPS Committee, who recommended that the experiment proceeds further to a Comprehensive Design phase. In its initial phase, the 400GeV proton beam extracted from the SPS will be dumped on a heavy target with the aim of integrating $2\times 10^{20}$ pot in 5 years. A dedicated detec ... More
Presented by Ahnnarita BUONAURA on 13 Apr 2016 at 4:53 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We apply a MC method to solve the evolution equations but use a gluon density from saturation models as input. The sea and valence quark disributions are obtained from fits to HERA precision data. We obtain TMD parton distributions (gluon and quarks) satisfying saturation conditions.
Presented by Sara TAHERI MONFARED on 14 Apr 2016 at 9:25 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
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 > 0.001, the inelasticity 0.2< y < 0.7 and the photon virtuality 150 < Q2 < 15000 GeV^2. The search is performed using H1 data corresponding to an integrated luminosity of 350 pb^-1. Several observable ... More
Presented by Stanislav MIKOCKI on 12 Apr 2016 at 2:25 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The proton-proton collisions at sqrt{s} = 13 TeV at the LHC have increased the ATLAS sensitivity to production of strongly produced supersymmetric particles. If R-parity is not conserved, these particles may decay to jets and leptons, and lightest supersymmetric particles may decay into many leptons with or without missing transverse momentum. Several supersymmetric models also predict massive lo ... More
Presented by Bradley Dean AXEN on 12 Apr 2016 at 12:40 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The search for the Higgs boson dimuon decay in standard model (SM) and its minimal supersymmetric extension (MSSM) based on the proton-proton collision data collected with the CMS detector at LHC is presented. To enhance the sensitivity of the search, events are categorised according to different production mechanisms and the dimuon invariant mass. Upper limits on the production cross section at 9 ... More
Presented by Dr. Adrian PERIEANU on 12 Apr 2016 at 9:20 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The results of inclusive searches for supersymmetry with all-hadronic events produced in proton-proton collision at 13 TeV are summarized. The data sample corresponds to an integrated luminosity of 2.3 fb-1 collected in 2015. The searches are based on jet multiplicity, bottom-quark jet multiplicity, and variables characterizing total event energy and missing transverse momentum. The results are in ... More
Presented by Bibhuprasad MAHAKUD on 12 Apr 2016 at 11:40 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
A search for a narrow baryonic state in the pKS0 and \bar{p}KS0 system has been performed in ep collisions at HERA with the ZEUS detector using an integrated luminosity of 358 pb−1 taken in 2003-2007. The search was performed with deep inelastic scattering (DIS) events at an ep centre-of-mass energy of 318 GeV for exchanged photon virtuality, Q2, between 20 and 100 GeV2. Contrary to evidenc ... More
Presented by Mr. Ryuma HORI on 12 Apr 2016 at 3:13 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Recent results on searches for additional scalar and pseudo-scalar neutral Higgs bosons are presented. These searches are well motivated within a variety of BSM models, from the MSSM or NMSSM to more general two Higgs doublet models. Heavy neutral scalar higgs (H) or pseudo-scalar (A) are searched in different final states. These studies are based on pp collision data collected at centre-­of-­ma ... More
Presented by Ram Krishna DEWANJEE on 12 Apr 2016 at 3:10 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Recent results on searches for exotic production and rare decays of the Higgs boson H(125) are presented. The current status of the searches for invisible and quasi invisible decays, decays to J/Psi+Gamma, and lepton flavour violation (emu, etau, mutau) decays of the boson will be reviewed, based on pp collision data collected at centre-­of-­mass energies of 7 and 8 TeV by the CMS collaboration ... More
Presented by Mr. Daniel TROENDLE on 12 Apr 2016 at 10:00 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Several "Beyond Standard Model" theories predict the existence of additional heavy Higgs particles or di-Higgs resonances, with sizeable contributions of fermionic decay channels. Searches are presented using the first run-2 data of 3.2 fb^(-1) at 13 TeV.
Presented by Dirk DUSCHINGER on 12 Apr 2016 at 2:50 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
A search is performed on the 8 TeV LHC data for additional scalars and pseudoscalar with masses below the newly discovered higgs boson h(125). These searches are motivated within several BSM theories, most significantly extensions of the non mininal extensions of the MSSM like the NMSSM, where additional scalar and pseudoscalar states are expected. The mass range from 350 MeV to 110 GeV is explore ... More
Presented by Benoit COURBON on 12 Apr 2016 at 2:30 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We have used the full D0 dataset consisting of 10.4 fb-1 of proton-antiproton collision data to search for new exotic QCD states. We report on the results in specific channels.
Presented by Mr. Iain BERTRAM on 14 Apr 2016 at 9:20 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Processes involving the FCNC transitions in b-hadron decays are suppressed in the SM and are sensitive to new physics. New results in the search for the rare decays of Bs and Bd into mu+mu- are presented. They are based on the full sample of data collected by ATLAS at 7 and 8 TeV of collision energy. The consistency with the SM and with other available measurements is discussed. The properties o ... More
Presented by Adrian John BEVAN on 12 Apr 2016 at 12:00 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
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 summarises the status of searches for gaugino and slepton pair production in final states with leptons.
Presented by Ciwake SHEHU on 12 Apr 2016 at 12:00 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Weak scale supersymmetry is one of the best motivated and studied extensions of the Standard Model. The recent increase in the center of mass energy of the proton-proton collisions gives a unique opportunity to extend the sensitivity to production of supersymmetric particles at the Large Hadron Collider. This talk summarises recent ATLAS results on searches for supersymmetric squarks and gluino ... More
Presented by Geert Jan BESJES on 12 Apr 2016 at 11:00 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Weak scale supersymmetry is one of the best motivated and studied extensions of the Standard Model. The recent increase in the center of mass energy of the proton-proton collisions gives a unique opportunity to extend the sensitivity to production of supersymmetric particles at the Large Hadron Collider. This talk summarises recent ATLAS results on searches for supersymmetric squarks and gluino ... More
Presented by Sebastien Jonathan KAHN on 12 Apr 2016 at 11:20 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The ATLAS collaboration has searched for the Standard Model Higgs Boson in the first run-2 data using 3.2 fb^(-1) at 13 TeV. Results are presented in terms of central value and limits on the fiducial and total cross-sections.
Presented by Maria Josefina ALCONADA VERZINI on 12 Apr 2016 at 9:00 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The search for the production of the Higgs Boson with a pair of top-anti-top quarks is both very important and very challenging. The final results from run-1 are presented, with about 20 fb^(-1) of data at 8 TeV, as well as first run-2 results with 3.2 fb^(-1) of data at 13 TeV.
Presented by Djamel Eddine BOUMEDIENE on 12 Apr 2016 at 9:40 AM
Session: Plenary
Presented by Michael KRÄMER on 11 Apr 2016 at 4:20 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Many physics scenarios beyond the standard model predict the existence of new particles decaying to dilepton, multilepton, and lepton+MET final states. This talk presents searches for BSM physics in these three final states at CMS, focusing on the recent results obtained using data collected at the LHC in 2015.
Presented by Laurent THOMAS on 13 Apr 2016 at 12:00 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Many physics scenarios beyond the standard model predict the existence of heavy resonances decaying to diphotons. This talk presents searches for BSM physics in the diphoton final state at CMS, focusing on the recent results obtained using data collected at the LHC in 2015.
Presented by Milena Eleonore QUITTNAT on 13 Apr 2016 at 11:15 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Many theories predict candidates to the dark matter particles that are light enough to be produced at the LHC. This talk presents the searches for dark matter at CMS, focusing on the recent results obtained using data collected in 2015.
Presented by Phat SRIMANOBHAS on 13 Apr 2016 at 11:45 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Resonant production of two bosons (gammagamma, VV, VH and HH) is a clear hint for physics beyond the Standard Model, potentially related to the nature of electroweak symmetry breaking mechanism in the SM. Searches for diboson resonances have been performed in gammagamma and in final states with different numbers of leptons and jets including cases where the two jets are merged into one beca ... More
Presented by Daniel BUESCHER on 12 Apr 2016 at 3:30 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Many new physics scenarios beyond the Standard Model predict resonant or non-resonant production of high-transverse momentum fermions or gluons. The high-mass resonant production of bottom-quark pairs is also a good benchmark process for high-pT b-quark tagging. This talk summarizes Run 2 searches for new physics in fermionic final states and jets at the ATLAS experiment in LHC.
Presented by Mr. Oleksandr VIAZLO on 13 Apr 2016 at 11:30 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
The presence of fermionic top/bottom quark partners, referred to as vector-like quarks (VLQs), may be an important ingredient for mechanism to cancel mass divergence for the Higgs boson required for “natural” theories beyond the Standard Model (SM). The VLQs typically couple preferentially to the third generation SM quarks. In addition, there are many extensions of the SM that predict new par ... More
Presented by Dr. James FERRANDO
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Double-parton scattering (DPS) effects were discussed recently for different reactions. So far no clear and spectacular effect was observed for jet production where single-parton scattering (SPS) contributions dominate. We discuss four-jet production at the LHC. We calculate cross section for both single-parton scattering (SPS) using the ALPGEN code and for double-parton scattering (DPS) in collin ... More
Presented by Dr. Rafal MACIULA on 14 Apr 2016 at 11:48 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We study the role of the non-perturbative input to the transverse momentum dependent (TMD) gluon density in hard processes at the LHC. We derive the input TMD gluon distribution at a low scale $\mu_0^2 \sim 1$~GeV$^2$ from a fit of inclusive hadron spectra measured at low transverse momenta in $pp$ collisions at the LHC and demonstrate that the best description of these spectra for larger ... More
Presented by Prof. Gennady LYKASOV on 14 Apr 2016 at 9:45 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Measurements of single top­quark production in proton proton collisions are presented. The measurements include the first such measurements from the 13 TeV ATLAS dataset. In the leading order process, a W boson is exchanged in the t­channel. The single top­quark and anti­top total production cross sections, their ratio, as well as a measurement of the inclusive production cross section i ... More
Presented by Mr. Patrick RIECK on 13 Apr 2016 at 2:30 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We discuss single inclusive hadron production from a high energy quark scattering off a strong target color field in the Color Glass Condensate formalism. Recent calculations of this process at the next-to-leading order accuracy have led to negative cross sections at large transverse momenta. We identify the origin of this problem in an oversubtraction of the rapidity divergence into the Balitsky- ... More
Presented by Dr. Bertrand DUCLOUE on 14 Apr 2016 at 10:00 AM
Session: WG6 Spin Physics
Track: Spin Physics
In high-energy hadron collisions, most energy goes into the forward region. However, particle production mechanisms in the forward region are not well understood as perturbative QCD is not applicable at small momentum transfers. We study single spin asymmetries (A_N) of forward neutron production in the PHENIX experiment using a transversely polarized proton beam. In 2015, we took data for p ... More
Presented by Dr. Kiyoshi TANIDA on 12 Apr 2016 at 11:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Measurements of single top quark production are presented, performed using CMS data collected in 2011, 2012 and 2015 at centre-of-mass energies of 7, 8 and 13 TeV respectively. 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-chan ... More
Presented by Soureek MITRA on 13 Apr 2016 at 2:50 PM
Session: WG7 Future Experiments
Track: Small-x, Diffraction and Vector Mesons
In this talk we will present a review on the possibilities for small-x studies at the LHeC and the FCC-he. We focus on the possibilities of discriminating standard DGLAP approaches from resummation and saturation scenarios in inclusive, semi-inclusive and exclusive observables. We also discuss the opportunities for studying a totally new kinematic regime in diffractive production, and for analysin ... More
Presented by Claire GWENLAN on 12 Apr 2016 at 6:08 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The measurement of the soft diffractive cross sections in single- and double-diffractive final states is presented at 7TeV. Furthermore, also the jet-gap-get production is discussed.
Presented by Dr. Marta RUSPA on 14 Apr 2016 at 11:20 AM
Session: WG6 Spin Physics
Track: Spin Physics
A mini review on the phenomenology of exclusive measurements in the deeply virtual region is presented, where some emphasis is given to deeply virtual Compton scattering measurements from JLAB and the first access of the 2$\pi$ generalized distribution amplitude from Belle measurements. Furthermore, new perturbative next-to-leading order results are reported.
Presented by Dieter MUELLER on 14 Apr 2016 at 11:00 AM
Session: Plenary
Track: Spin Physics
Presented by Dr. Emanuele Roberto NOCERA, Dr. Erin SEDER, Dr. Silvia PISANO, Dr. Salvatore FAZIO on 15 Apr 2016 at 2:20 PM
Session: Plenary
Presented by Ralf SEIDL on 11 Apr 2016 at 3:10 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We investigate the stability of the saturation regime of the Gribov-Levin-Ryskin equation against azimuthal perturbations, and argue that the appearance of unstable modes could lead to the "spontaneus symmetry breaking" of azimuthal symmetry in high energy pp and AA collisions. We discuss the phenomenology of this hypothesis in light of the "harmonic flow" observable seen in heavy ion collis ... More
Presented by Mr. Guillermo GAMBINI on 14 Apr 2016 at 12:40 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
It has been shown that power-law hadron spectra observed in jets stemming from high-energy ee and pp collisions can be described by a statistical hadronisation model based on microcanonical statistics and superimposed Negative-Binomial (NBD) multiplicity fluctuations [1,2,3]. In this talk, applications of this model to ep DIS are discussed: fits to fragmentation functions and multiplicity distribu ... More
Presented by Karoly URMOSSY on 12 Apr 2016 at 10:05 AM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Review of NNLO+PS
Presented by Dr. Simone ALIOLI on 13 Apr 2016 at 11:00 AM
Session: Plenary
Track: Structure Functions and Parton Densities
Presented by Dr. Katarzyna WICHMANN, Prof. Ronan MCNULTY, Prof. Robert THORNE on 15 Apr 2016 at 11:30 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We study the reaction e+ e− -> gamma_ISR J/psi, where J/psi -> pi+ pi- pi0, and J/psi -> K+ K- pi0, using events obtained from the Initial State Radiation process. We measure the relative J/psi branching fraction and perform a Dalitz plot analysis of both J/psi decay modes using an isobar and a Veneziano model. We present also an analysis of the process gamma gamma -> K anti-K pi. We observe ... More
Presented by Elisa FIORAVANTI on 14 Apr 2016 at 12:20 PM
Session: WG7 Future Experiments
Track: Future Experiments
A future Electron-Ion Collider (EIC) facility will deliver electron-nucleon luminosity of 10^33􀀀-10^34cm􀀀^-2sec􀀀^-1 for collisions of polarized electron and protons and heavy ions over a wide range in center-of-mass energies (40 GeV to 145 GeV). One of its promising physics programs is to study the partonic structure of quasi-real photons. By utilizing di-jet measurement in photoproductio ... More
Presented by Ms. Xiaoxuan CHU on 14 Apr 2016 at 11:23 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Measurements of the lepto-production of vector mesons have always been pivotal in the development of a theory of hadron dynamics, challenging and elucidating the paradigm of the moment and thereby guiding our understanding of it to its present status in terms of QCD. Always with an experimentalist's appreciation of the momentous theoretical achievements of more recent years with QCD in mind, first ... More
Presented by Prof. John DAINTON on 12 Apr 2016 at 9:20 AM
Session: WG6/WG7 joint session (spin+future exp.)
Track: Spin Physics
(for the SoLID Collaboration) The Solenoidal Large Intensity Device (SoLID) has been proposed in Hall A at Jefferson Lab, which will fully utilize the great physics potential of the 12-GeV energy upgrade by combining high luminosities and large acceptance. Three of five highly-rated approved experiments are the semi-inclusive deep inelastic scatterings (SIDIS) of 11 GeV and 8.8 GeV electron beams ... More
Presented by Dr. Tianbo LIU on 13 Apr 2016 at 3:39 PM
Session: WG6/WG7 joint session (spin+future exp.)
Track: Future Experiments
We report on the opportunities for spin physics and Transverse-Momentum Dependent distribution (TMD) studies at a future multi-purpose fixed-target experiment using the proton LHC beams extracted by a bent crystal or using an internal gas target. The LHC multi-TeV beams allow for the most energetic fixed-target experiments ever performed, opening new domains of particle and nuclear physics and com ... More
Presented by Jean-Philippe LANSBERG on 13 Apr 2016 at 2:30 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present the TMDlib project which contains a collection on transverse momentum dependent (TMD) parton distributions obtained in different frameworks. The TMDplotter is a a web based plotting tool for TMD parton distributions as well as for collinear parton distributions included in LHAPDF. TMDplotter has additional plotting features, such as parton luminosities for collinear and TMD parton dis ... More
Presented by Patrick CONNOR on 14 Apr 2016 at 10:05 AM
Session: WG6 Spin Physics
Track: Spin Physics
We cover the general structure of the SIDIS cross section with a polarized beam and spin-1 target. The cross section is characterized by 41 structure functions of which 23 are unique to the spin-1 target case. Next, we study a specific example, namely DIS off a polarized deuteron with a slow detected nucleon in the final state ("tagged spectator DIS"). The reaction is studied in the impulse app ... More
Presented by Prof. Wim COSYN on 12 Apr 2016 at 10:10 AM
Session: WG7 Future Experiments
Track: Future Experiments
The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the LHC. Jointly with the other calorimeters it is designed for reconstruction of hadrons, jets, tau-particles and missing transverse energy. It also assists in the muon identification. A summary of the upgrades and performance results for TileCal using pp collisions from the initial LHC Run II at 13 TeV ... More
Presented by Tomas DAVIDEK on 14 Apr 2016 at 9:23 AM
Session: WG7 Future Experiments
Track: Future Experiments
The Belle II experiment at the asymmetric $e^+e^-$ SuperKEKB collider is a major upgrade of the Belle experiment, which ran at the KEKB collider at the KEK laboratory in Japan. The design luminosity of SuperKEKB is $8\times 10^{35}$~cm$^{-2}$\,s$^{-1}$, which is about 40 times higher than that of KEKB. Commissioning of the main ring of SuperKEKB has started in February of this year and Belle~II is ... More
Presented by Dr. Carlos MARINAS on 13 Apr 2016 at 5:16 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present a new set of leading twist parton distribution functions, referred to as “CJ15”, which take advantage of developments in the theoretical treatment of nuclear corrections as well as new data. The analysis includes for the first time data on the free neutron structure function from Jefferson Lab and new high-precision charged lepton and W -boson asymmetry data from Fermilab. These sig ... More
Presented by Alberto ACCARDI, Alberto ACCARDI on 12 Apr 2016 at 11:40 AM
Session: WG7 Future Experiments
Track: Future Experiments
The Compact Linear Collider (CLIC) is a multi-TeV electron-positron collider under development. It offers the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. To optimise its physics output CLIC is foreseen to be built and operated in several energy stages, ranging from ~350 GeV to 3 TeV centre-of mass energy. The CLIC physics potentia ... More
Presented by Aidan ROBSON on 13 Apr 2016 at 10:09 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
The Parton Distribution Functions(PDFs) are the non-perturbative input of the theoretical calculation of physical observable in a hadron collider. In the era of precision measurement, the uncertainty estimation of the PDFs is sensitive to the searching of new physics. In this talk, the CT14 Monte Carlo replica and its comparison with the CT14 Hessian sets would be presented.
Presented by Dr. Tie-Jiun HOU on 13 Apr 2016 at 5:50 PM
The CBM experiment will investigate highly compressed baryonic matter created in A+A collisions at the new FAIR accelerator. With a beam energy range up to 11 AGeV for the heaviest nuclei at the SIS 100 accelerator, CBM will investigate the QCD phase diagram in the intermediate range, i.e. at moderate temperatures but high net-baryon densities. This research program is thus complementary to t ... More
Presented by Dr. Claudia HOEHNE on 14 Apr 2016 at 12:31 PM
Session: WG7 Future Experiments
Track: Future Experiments
The Electron-Ion Collider (EIC) is envisioned as the next-generation U.S. facility to study quarks and gluons in strongly interacting matter. The broad physics program of the EIC aims to precisely image gluons in nucleons and nuclei and to reveal the origin of the nucleon spin by colliding polarized electrons with polarized protons, polarized light ions, and heavy nuclei at high luminosity. Th ... More
Presented by Dr. Markus DIEFENTHALER on 13 Apr 2016 at 12:32 PM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
Monte Carlo event generators are currently very important tools for the comparison between theory and experiment at particle colliders. Today, these tools typically reach NLO precision in QCD for the fixed-order matrix element. In order to improve this precision, Monte Carlo event generators must compute to NLO in EW as well as to NNLO in QCD. The inclusion of a full NLO EW calculation is computat ... More
Presented by Dr. Jennifer THOMPSON on 13 Apr 2016 at 5:50 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
Significant progress has recently been made, both experimentally and theoretically, in extracting the neutron structure function from deuterium data. Of particular note are the new CTEQ-JLab (CJ) nuclear corrections for large x PDF extraction, and the Jefferson Lab "BONUS" experiment, where a novel tagged proton spectator approach was employed to isolate the neutron target in electron-deuteron sca ... More
Presented by Dr. Cynthia KEPPEL on 13 Apr 2016 at 9:00 AM
Session: Plenary
Presented by Paul NEWMAN on 11 Apr 2016 at 9:50 AM
Session: WG3 Electroweak Physics and Beyond the Standard Model
Track: Electroweak Physics and Beyond the Standard Model
I discuss the current status of theoretical and experimental constraints on the real Higgs singlet extension of the Standard Model. For the second neutral (non-standard) Higgs boson the full mass range from 1 GeV to 1 TeV accessible at past and current collider experiments is considered. I present benchmark scenarios for searches for an additional Higgs state in the real Higgs singlet extension of ... More
Presented by Dr. Tania ROBENS on 13 Apr 2016 at 4:50 PM
Session: WG7 Future Experiments
Track: Future Experiments
With the discovery of the Higgs boson at LHC, all particles of the Standard Model have been observed experimentally, yet many questions are left unanswered. The discovery has intensified the planning for future high-energy colliders, which aim to probe the Standard Model and the mechanism of electroweak symmetry breaking with higher precision and to extend and complement the search for new particl ... More
Presented by Naomi VAN DER KOLK on 12 Apr 2016 at 4:30 PM
Session: WG7 Future Experiments
Track: Future Experiments
The Large Hadron Electron Collider is the proposal of an upgrade of the LHC to study ep/eA collisions with a centre-of-mass energy in the TeV regime using an about 60 GeV electron beam. In the future, the lepton beams could be combined with the HE-LHC or FCC hadron beams, to study DIS at even higher energies. In this talk we will present an update of the status of the project, with emphasis on the ... More
Presented by Paul NEWMAN on 12 Apr 2016 at 4:53 PM
Session: WG7 Future Experiments
Track: Future Experiments
The Mu2e Experiment at Fermilab will search for coherent, neutrinoless conversion of muons into electrons in the field of a nucleus with a sensitivity improvement of a factor of 10,000 over previous experiments. Such a charged lepton flavor-violating reaction probes new physics at a scale inaccessible with direct searches at either present or planned high energy colliders. The experiment both comp ... More
Presented by Luca MORESCALCHI on 13 Apr 2016 at 4:30 PM
Session: WG7 Future Experiments
Track: Future Experiments
The PANDA experiment in preparation to be setup at FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany will cover many important aspects of hadron physics with cooled anti-proton beams of unprecedented intensity and precision in the momentum range between 1.5 and 15 GeV/c. The versatile detector is designed to address a rich physics program. This includes spectroscopy of ... More
Presented by Marc PELIZAEUS on 14 Apr 2016 at 10:09 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present an updated recommendation for the usage of sets of parton distribution functions at the LHC Run II. We propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. We discuss tools which allow for the delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Car ... More
Presented by Dr. Juan ROJO, Dr. Juan ROJO on 12 Apr 2016 at 12:00 PM
Session: WG6/WG7 joint session (spin+future exp.)
Track: Future Experiments
The exploration of the fundamental structure of strongly interacting matter has always thrived on the complementarity of lepton scattering and purely hadronic probes. As the community eagerly anticipates a future electron ion collider (EIC) in the U.S., an outstanding scientific opportunity remains to complete "must-do" measurements in p+p and p+A physics at RHIC in the years preceding the EIC. It ... More
Presented by Dr. Elke-Caroline ASCHENAUER on 13 Apr 2016 at 2:53 PM
Session: WG7 Future Experiments
Track: Future Experiments
The ZEUS data preservation (ZEUS DP) project assures continued access to the data and documentation related to the experiment. It aims to provide the ability to continue the generation of valuable scientific results from these data in the future. This talk presents analysis opportunities within the ZEUS DP project and its benefits for the physics community. The implications of the preserved d ... More
Presented by Dr. Andrii VERBYTSKYI on 14 Apr 2016 at 9:00 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
I will present a state-of-the-art prediction for the prompt atmospheric neutrino flux in the framework of perturbative QCD. The calculation was performed using a gluon PDF constrained at small-x by the inclusion of charm production measurements from the LHCb experiment at 7 TeV, and recently validated with the corresponding 13 TeV data [arXiv:1511.06346, arXiv:1506.08025]
Presented by Mr. Luca ROTTOLI on 14 Apr 2016 at 11:00 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Assuming the form $\sigma^{\gamma P} \propto l^{\lambda_{\rm eff}}$ at fixed $Q^2$ for the behavior of the virtual-photon proton scattering cross section, where $l$ is the coherence length of the photon fluctuations, it is seen that the extrapolated values of $\sigma^{\gamma P}$ for different $Q^2$ cross for $l\approx 10^8$~fm. It is argued that this behavior is not physical, and that the behavior ... More
Presented by Allen CALDWELL on 12 Apr 2016 at 9:00 AM
Session: WG6 Spin Physics
Track: Spin Physics
The Sivers effect describes the correlation between the spin of the nucleon and the orbital motion of partons. For gluons it has been measured at COMPASS via $J/\Psi$ production and via high-$p_T$ hadron pair production in Semi-Inclusive Deep Inelastic Scattering of a 160 GeV/$c$ muon beam off transversely polarised proton and deuteron targets by determining the amplitude of the modulation of th ... More
Presented by Mr. Adam SZABELSKI on 12 Apr 2016 at 3:20 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
We will present a study of high-energy jet production in the multi-Regge limit making use of the Monte Carlo code BFKLex which includes collinear improvements in the form of double-log contributions. Making use of the anti-kt jet algorithm in the FastJet implementation, we will present results for the average transverse momentum and azimuthal angle of the produced jets when two tagged forward/back ... More
Presented by Dr. Grigorios CHACHAMIS on 12 Apr 2016 at 3:30 PM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
A new update of the ABM PDFs is presented, which, among other data, includes the new combined HERA DIS data from run II.
Presented by Sergey ALEKHIN, Dr. Sergey ALEKHIN, Sergey ALEKHIN, Dr. Sergey ALEKHIN, Sergey ALEKHIN on 12 Apr 2016 at 11:20 AM
Session: WG7 Future Experiments
Track: Future Experiments
eRHIC is one of the options proposed as a high luminosity, polarized Electron-Ion Collider (EIC) that is based on using one of the RHIC hadron rings and a multipass Energy Recovery Linac. A beam of polarized electrons with an energy up to 21 GeV would collide with a variety of ion species, from polarized protons with a top energy of 250 GeV to fully-stripped uranium ions with energies up to 100 Ge ... More
Presented by Dr. Klaus DEHMELT on 13 Apr 2016 at 11:23 AM
Session: WG6 Spin Physics
Track: Spin Physics
The longitudinal double spin asymmetries <i>A</i><sub>1</sub><sup><i>p</i></sup> and the spin dependent structure function of the proton <i>g</i><sub>1</sub><sup><i>p</i></sup> were extracted from COMPASS data in the region of low <i>x</i> and low <i>Q</i><sup>2</sup>. The data were taken on 2007 and 2011 from scattering of polarised muons off polarised protons, resulting in a sample that is 150 t ... More
Presented by Ana Sofia NUNES on 13 Apr 2016 at 11:20 AM
Session: WG6 Spin Physics
Track: Spin Physics
A major part of the COMPASS-II program will be dedicated to the investigation of generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs), which aim for the most complete description of the partonic structure of the nucleon. GPDs are experimentally accessible via lepton-induced exclusive reactions, in particular the Deeply Virtual Compton Scatt ... More
Presented by Mr. Philipp JÖRG on 13 Apr 2016 at 5:20 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Over 30 years of the J/psi discovery the mechanisms behind quarkonium production are still not fully understood. The effective field theory framework of Nonrelativistic QCD (NRQCD) provides a rigorous factorization theorem for quarkonium production, which has become a standard description, also due to its phenomenological successes. In this talk we will review the state of the art in the field of ... More
Presented by Dr. Mathias BUTENSCHÖN on 14 Apr 2016 at 11:20 AM
Session: WG6 Spin Physics
Track: Spin Physics
We study the cross section for the photoproduction process gamma N -> h X where the incident photon and nucleon are longitudinally polarized and a hadron h is observed at high transverse momentum. Specifically, we address the "direct" part of the cross section, for which the photon interacts in a pointlike way. For this contribution we perform an all-order resummation of logarithmic threshold corr ... More
Presented by Ms. Claudia UEBLER on 13 Apr 2016 at 10:10 AM
Session: Plenary
Presented by Orso IORIO on 11 Apr 2016 at 5:40 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Measurements of the inclusive and differential top quark pair production cross section at 7 TeV, 8 TeV and 13 TeV are presented, performed using CMS data collected in 2011, 2012 and 2015. 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 obtaine ... More
Presented by Mr. Nazar BARTOSIK on 13 Apr 2016 at 9:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
State-of-the-art theoretical predictions accurate to next-to-leading order QCD interfaced with Pythia8 and Herwig++ event generators are tested by comparing the unfolded ttbar differential data collected with the CMS detector at 8 TeV. These predictions are also compared with the underlying event activity distributions in ttbar events using CMS proton-proton data collected in 2015 at a center of m ... More
Presented by Bugra BILIN on 13 Apr 2016 at 3:30 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
The lack of knowledge how the top quark mass parameter in Monte-Carlo event generators (MCs) is related to field theoretically defined mass schemes limits the theoretical interpretation of the top quark mass measurements based on templates obtained from direct reconstruction analyses at hadron colliders. In the first part of the talk I review the conceptual aspects of the problem and argue ... More
Presented by Prof. Andre HOANG on 13 Apr 2016 at 12:40 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
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 de ... More
Presented by Mr. Simon SPANNAGEL on 13 Apr 2016 at 11:40 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Precise measurements of the properties of the top quark test the Standard Model (SM) and can be used to constrain new physics models. The top quark pair charge asymmetry is an asymmetry predicted to occur beyond leading­order QCD in the SM, and may be significantly enhanced by the presence of new physics. The ttbar production charge asymmetry is measured inclusively and differentially using t ... More
Presented by Mohammad KAREEM on 13 Apr 2016 at 10:00 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
Measurements of the inclusive and differential top­quark pair cross sections in proton­proton collisions at both 8 and 13 TeV with the ATLAS detector at the Large Hadron Collider are presented. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. Differential measurements of the kinematic properties of the top quark production are ... More
Presented by Mr. Hasib AHMED on 13 Apr 2016 at 9:20 AM
Session: WG6 Spin Physics
Track: Spin Physics
Accessing the Sivers TMD function in proton+proton collisions through the measurement of transverse single spin asymmetries (TSSAs) in Drell-Yan and weak boson production is an effective path to test the fundamental QCD prediction of the non-universality of the Sivers function. Furthermore, it provides data to study the spin-flavor structure of valence and sea quarks inside the proton and to t ... More
Presented by Dr. Salvatore FAZIO on 12 Apr 2016 at 11:40 AM
Session: WG6 Spin Physics
Track: Spin Physics
Semi-inclusive deep-inelastic lepton-nucleon scattering provides a powerful tool for unraveling the multi-dimensional internal spin-momentum structure of the nucleon. In particular, the dependence on transverse momentum of the produced hadron allows the study of numerous novel effects like the Sivers and Collins mechanism. The HERMES experiment, with its versatile gas target internal to the HERA l ... More
Presented by Ms. Charlotte VAN HULSE on 12 Apr 2016 at 12:40 PM
Session: WG6 Spin Physics
Track: Spin Physics
We study the transverse porlarization of hyperons produced in the high-energy unporlarized proton-proton collision in the framework of the collinear factorization. This phenomenon is one of the twist-3 observables and twist-3 distribution and fragmentation functions contribute. In this work, we focus on the former contribution and derive the LO complete cross-section. For the soft-gluon-pole term, ... More
Presented by Mr. Kenta YABE on 12 Apr 2016 at 5:10 PM
Session: WG6 Spin Physics
Track: Spin Physics
We discuss the twist-3 contributions to the double-spin asymmetry A_{LT} for light hadron production in collisions between transversely and longitudinally polarized protons. So far only twist-3 effect in the transversely polarized proton have been studied for A_{LT}. In this talk, we discuss other possible twist-3 contributions in order to derive the complete leading-order cross section formula fo ... More
Presented by Dr. Shinsuke YOSHIDA on 12 Apr 2016 at 4:50 PM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
In 2010 and 2011, the STAR Collaboration collected a large sample of triggers for ultra-peripheral collisions.In this talk, I will present several new results involving photonuclear interactions in ultra-peripheral relativistic heavy ion collisions (UPCs). I will present an analysis of 384,000 photoproduced pion pairs, coming from rho, omega and direct pion pair production.The omega component is c ... More
Presented by Dr. Spencer KLEIN on 13 Apr 2016 at 10:00 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
Ultra-Peripheral Pb-Pb collisions, in which the two nuclei pass close to each other but at an impact parameter greater than the sum of their radii, provide information about the initial state of nuclei. In particular, J/psi production in such collisions proceeds by photon-gluon interactions, and gives access to nuclear PDFs. The ALICE collaboration has published measurements of UPC J/Psi productio ... More
Presented by Ms. Katie GRAHAM on 13 Apr 2016 at 3:10 PM
Session: WG2 QCD and Hadronic Final States
Track: QCD and Hadronic Final States
Review of MC for heavy ions.
Presented by Dr. Korinna ZAPP on 12 Apr 2016 at 11:24 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
We present continuing work on the the MMHT PDFs. We discuss the changes in the PDFs and predictions due to variation in heavy quark masses. We present in detail the impact of the final combined HERA cross section data, and examine the fit quality. We also highlight plans for the future, in particular the potential impact of data sets not included in the current fit, and of new theoretical calculat ... More
Presented by Prof. Robert THORNE, Prof. Robert THORNE on 12 Apr 2016 at 9:00 AM
Session: WG2/WG3 joint session (QCD+EW)
Track: Electroweak Physics and Beyond the Standard Model
Run I & II measurements of a vector boson (V=W, Z and photon) produced in association with jets from CMS
Presented by Mr. Fengwangdong ZHANG on 13 Apr 2016 at 10:10 AM
Session: WG2/WG3 joint session (QCD+EW)
Track: Electroweak Physics and Beyond the Standard Model
Run I & II electroweak studies of vector boson production
Presented by Dr. Ji Yeon HAN on 13 Apr 2016 at 9:25 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
Photons and weak bosons do not interact strongly with the dense and hot medium formed in the nuclei collisions, thus should be sensitive to the nuclear modification of parton distribution functions (nPDFs). The in-medium modification of heavy Charmonium states plays an important role in studying the hot and dense medium formed in the larger collision systems. The ATLAS detector, optimized for sear ... More
Presented by Markus Konrad KOHLER on 13 Apr 2016 at 11:00 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The strong electromagnetic fields generated by ultra-relativistic heavy ions offer the possibility to study gamma-gamma, gamma-nucleus and gamma-proton processes at the LHC in ultra-peripheral Pb-Pb and p-Pb collisions (UPC). As exclusive photoproduction of vector mesons is sensitive to the gluon distribution of the interacting target it allows one to study saturation and shadowing phenomena. ... More
Presented by Jaroslav ADAM on 13 Apr 2016 at 9:40 AM
Session: WG5 Small-x and Diffraction
Track: Small-x, Diffraction and Vector Mesons
The distribution of electromagnetic and hadronic energy in the very forward phase-space is measured with the CASTOR calorimeters located at a pseudorapidity of -5.2 to -6.6 in the very forward region of CMS. The energy distributions are very powerful benchmarks to study the performance of MPI in hadronic interactions models at 13TeV collision energy. Furthermore, also the jet-spectra for very low- ... More
Presented by Alex Beaudoin E VAN SPILBEECK on 14 Apr 2016 at 9:00 AM
Session: WG1/WG3 joint session (EW+PDF)
Track: Structure Functions and Parton Densities
LHCb's unique forward acceptance allow for measurements of EW and hard QCD processes at large rapidity. In this talk the latest LHCb results on W, Z and top production are presented.
Presented by Lorenzo SESTINI on 13 Apr 2016 at 3:40 PM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
We present the measurement of the differential cross-section of the X(3872) state through its decays to J/psi pi pi final state . The cross-section was extracted for both prompt and non-prompt production. The existence of the X(3872) suggests the presence of its bottomonium counterpart X_b. Search for X_b with the ATLAS experiment in several final states, including Upsilon pi pi, is presented.
Presented by Konstantinos KORDAS on 14 Apr 2016 at 9:40 AM
Session: WG4 Heavy Flavours
Track: Heavy Flavours (Charm, Beauty and Top)
The BESIII Experiment collected large data samples for electron-positron collisions with center-of-mass above 4 GeV during 2013 and 2014. The analysis of these samples has resulted in a number of surprising discoveries, such as the discoveries of the electrically charged "Zc" structures, which, if resonant, cannot be accomodated in the traditional charm quark and anti-charm quark picture of charmo ... More
Presented by Dr. Aiqiang GUO on 14 Apr 2016 at 9:00 AM
Session: WG6 Spin Physics
Track: Spin Physics
The STAR experiment at RHIC has provided significant contributions to our understanding of the structure of the proton. The STAR experiment is well equipped to measure $W^\pm \rightarrow e^\pm + \nu$ in $\sqrt{s}=510$ GeV longitudinally polarized $p+p$ collisions at mid-rapidity ($|\eta|<1$). W single-spin asymmetries, $A_L$, measured as a function of decay positron (electron) pseudo-rapidity $\et ... More
Presented by Prof. Bernd SURROW on 13 Apr 2016 at 12:20 PM
Session: WG1/WG7 joint session (PDF+future exp.)
Track: Future Experiments
In this talk we will present a review on the possibilities for nuclear studies at the LHeC and the FCC-he. We will show an update on the possibilities for a precise determination of nuclear PDFs, and their complete unfolding, in a kinematic region never explored before in DIS. We will also discuss diffractive and exclusive observables and the possibilities which these offer for constraining nucle ... More
Presented by Dr. Ilkka HELENIUS on 12 Apr 2016 at 3:37 PM
Session: WG7 Future Experiments
Track: Future Experiments
In this talk I present current design of our future electron-ion collider (EIC) at BNL, eRHIC. It is based on the existing Relativistic Heavy Ion Collider (RHIC) hadron facility, with two intersecting superconducting rings, each 3.8 km in circumference. We plan adding a polarized electron-beam with energy tunable within the 5-20 GeV range to collide with variety of species in the existing RHIC-acc ... More
Presented by Prof. Vladimir LITVINENKO on 13 Apr 2016 at 9:00 AM
Session: WG1 Structure Functions and Parton Densities
Track: Structure Functions and Parton Densities
An accurate knowledge of the Parton Distribution Functions (PDF) plays a critical role for the precision tests of the Standard Model (SM) and impact substantially the theory predictions of Beyond SM high mass production. We present the xFitter project (former HERAFitter) which provides a unique open-source software framework for the determination of the proton's PDFs and for the interpreta ... More
Presented by Mr. Oleksandr ZENAIEV on 13 Apr 2016 at 5:30 PM