# XLV International Symposium on Multiparticle Dynamics

4-9 October 2015
Europe/Berlin timezone
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## Contribution List

Displaying 96 contributions out of 96
Type: Poster Session: Poster session
Track: Multiparticle Correlations and Fluctuations
A new distribution is obtained from a convolution of the Generalized Multiplicity Distribution (GMD) with the Negative Binomial Distribution (NBD). This distribution models the charged particle production from hard and soft processes, with comparisons made with other multiplicity distribution models. A phenomenologically analogous Lee-Yang phase transition is examined using the new model.
Presented by Mr. Qixiang LEONG on 5 Oct 2015 at 19:25
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
I discuss a model based on Coloured-Glass-Condensate/saturation and the BFKL Pomeron. I show that this model successfully describes the elastic, diffractive and inclusive data at LHC energies. The talk is based on material appearing in arXiv:1408.3811, arXiv:a502.05202 and arXiv: 1503.04294
Presented by Prof. Errol (Asher) GOTSMAN on 5 Oct 2015 at 15:15
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
Using a viscosity-based survival scale for geometrical perturbations formed in the early stages of relativistic heavy-ion collisions, we model the radial flow velocity during freeze-out. Subsequently, we employ the Cooper-Frye freeze-out prescription, with first-order viscous corrections to the distribution function, to obtain the transverse momentum distribution of particle yields and flow harmon ... More
Presented by Dr. Amaresh JAISWAL on 7 Oct 2015 at 09:00
Type: Poster Session: Poster session
Track: Status of QCD
We present new measurements of the associated production of quarkonium with a vector boson or an additional quarkonium state using the ATLAS Run-1 dataset. These rare processes provide new insight into QCD models of quarkonium production, but also provide new opportunities to study double parton scattering, including cross-section measurements in single and double parton scattering dominated ... More
Presented by Prof. Dick GREENWOOD on 5 Oct 2015 at 19:05
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
In the context of data modeling and comparisons between different fit models, Bayesian analysis calls that model best which has the largest evidence, the prior-weighted integral of the likelihood function over model parameters. Evidence calculations automatically take into account both the usual chi-squared measure and an Occam factor which quantifies the price for adding extra parameters. Applyin ... More
Presented by Hans EGGERS on 5 Oct 2015 at 11:56
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
Production of heavy photons (Drell-Yan), gauge bosons, Higgs bosons, heavy flavors, which is treated within the QCD parton model as a result of hard parton-parton collision, should be treated as a bremsstrahlung process seeing in the rest frame of the target. The main observation is a dramatic breakdown of diffractive QCD factorization due to the interplay between soft and hard interactions, w ... More
Presented by Prof. Boris KOPELIOVICH on 5 Oct 2015 at 17:30
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
We shall describe the physics program with tagged forward protons, focusing on Central Exclusive Production (CEP) in polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC), with the STAR detector at \sqrt{s} = 200 GeV. Preliminary results in CEP of two oppositely charged pions and kaons produced in the processes $pp\to pp \pi^+\pi^-$ and $pp\to pp \K+\K^-$ shall be presen ... More
Presented by Dr. Wlodek GURYN on 5 Oct 2015 at 16:30
Type: Poster Session: Poster session
Track: Status of QCD
V.I.Kuvshinov It is shown that in the model of stochastic QCD vacuum colour quark confinement can be described as decoherence of pure colour state of the particle into the mixed quantum state with equal probabilities for different colours as a result of density marix evolution. Quantum functions of Purity, Fidelity and Fon Neiman entropy for one- and multi-particles states are calculated.
Presented by Prof. Viacheslav KUVSHINOV on 5 Oct 2015 at 18:30
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
H1 and ZEUS have published single-differential cross sections for inclusive D* meson production in deep-inelastic ep scattering at HERA from their respective final data sets. These cross sections are combined in the common visible phase space region of photon virtuality Q^2 > 5 GeV^2, electron inelasticity 0.02 < y < 0.7 and the D* meson's transverse momentum p_T (D*)> 1.5 GeV and pseudorapidity | ... More
Presented by Achim GEISER on 8 Oct 2015 at 16:45
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
A combination is presented of all inclusive deep inelastic cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current ep scattering for zero beam polarisation. The data correspond to an integrated luminosity of about 1 fb^-1 and span six orders of magnitude in negative four-momentum-transfer squared, Q2, and Bjorken x. The correlations of the syst ... More
Presented by Dr. Iris ABT on 8 Oct 2015 at 14:20
Type: Poster Session: Poster session
Track: Status of QCD
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. Present ... More
Presented by Dr. Andrii VERBYTSKYI on 5 Oct 2015 at 19:00
Type: Oral Presentation Session: Astroparticle Physics
Track: Astroparticle Physics
I shall review the state-of-the-art concerning the treatment of high energy cosmic ray interactions in the atmosphere, discussing in some detail the underlying physical concepts and presenting a comparison of model results with selected accelerator data. Further, the relation of basic characteristics of hadronic interactions with the properties of nuclear-electromagnetic cascades induced by prim ... More
Presented by Dr. Sergey OSTAPCHENKO on 6 Oct 2015 at 11:40
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
It is shown that de-confinement can be achieved in high multiplicity non jet $\bar{p}p$ collisions at $\sqrt{s}$= 1.8 TeV Fermi National Accelerator Laboratory(FNAL- E735) experiment. In this paper we use the same data but analyze the transverse momentum spectrum in the framework of the clustering of color sources. This frame-work naturally predicts the reduction in the charged particle multiplici ... More
Presented by Prof. L GUTAY on 7 Oct 2015 at 11:50
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
I will review the current status of equation of state calculations and deconfinement transition in 2+1 flavor QCD obtained using lattice calculations. I will discuss aspects of deconfinement related to fluctuations of conserved charges and screening of color charges in the deconfined medium using expectation value of Polyakov loop and Polyakov loop correlators.
Presented by Peter PETRECZKY on 8 Oct 2015 at 09:00
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
We present the latest determination of the strong-coupling constant from the quantum chromodynamics static energy. It comes from comparing three-loop perturbative QCD with 2+1 unqueched lattice data and provides up to date one of the most accurate low-energy determinations of alpha_s.
Presented by Antonio VAIRO on 8 Oct 2015 at 11:50
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
It is shown that “soft” proton-proton collisions at the LHC, from 2 TeV and beyond are dominated by Pomeron exchange. This is quantified e.g. by fitting the elastic scattering cross-section to the available (7 and 8 TeV) data, where the contribution from secondary Reggeons is shown to be smaller than the relevant experimental errors. A tiny Odderon contribution is also scrutinized and its par ... More
Presented by Prof. Laszlo JENKOVSZKY on 5 Oct 2015 at 15:30
Type: Oral Presentation Session: First Results from LHC Run II
Track: First Results from LHC Run II
Since a few months the LHC has started to deliver pp collisions at the unprecedented centre-of-mass energy of 13 TeV. The ATLAS collaboration has analysed this very early Run 2 data taken in both special conditions with very low pileup and those dedicated to high pT physics. This talk is an overview of hard QCD Results at 13 TeV. The production of high pT jets, photons and diphotons were studied. ... More
Presented by Mr. Nicola ORLANDO on 9 Oct 2015 at 10:10
Type: Oral Presentation Session: First Results from LHC Run II
Track: First Results from LHC Run II
Since a few months the LHC has started to deliver pp collisions at the unprecedented centre-of-mass energy of 13 TeV. The ATLAS collaboration has analysed this very early Run 2 data taken in both special conditions with very low pileup and those dedicated to high pT physics. This talk is an overview of soft QCD Results at 13 TeV. The properties of minimum bias interactions as well as the "underlyi ... More
Presented by Hideyuki OIDE on 9 Oct 2015 at 09:40
Type: Poster Session: Poster session
Track: Multiparticle Correlations and Fluctuations
Non-statistical event-by-event fluctuations in relativistic heavy ion collisions have been proposed as probe of phase instabilities near the QCD phase transition. The observable νdyn, which is given in terms of the moments of identified-particle multiplicity distributions, is used to quantify the magnitude of the dynamical fluctuations in event-by-event measurements of given particle ratios. The ... More
Presented by Mr. Sumit BASU on 5 Oct 2015 at 18:45
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
Event-by-event fluctuations in relativistic heavy-ion collisions may reveal important information about the QCD phase transition and can be used for characterizing the hot and dense system formed in heavy-ion collisions. Fluctuations of many observables are associated with thermodynamic quantities of the strongly interacting system. The event-by-event fluctuations of the mean transverse momentum, ... More
Presented by Mr. Sumit BASU on 5 Oct 2015 at 09:49
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
The TOTEM experiment has made a precise measurement of the elastic proton-proton differential cross-section at the centre-of-mass energy sqrt(s) = 8 TeV based on a high-statistics data sample obtained with the beta* = 90 optics. Both the statistical and systematic uncertainties remain below 1%, except for the t-independent contribution from the overall normalisation. This unprecedented precision a ... More
Presented by Prof. Tamas CSORGO on 5 Oct 2015 at 14:55
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
Exclusive central hadronic systems from hadron collisions result primarily from double pomeron exchange, and these have very restrictive quantum numbers: $I^{G}J^{PC}$ = $0^+ (\text{even})^{++}$. This "quantum number filter" is a powerful tool for meson spectroscopy in the isoscalar sector, especially for glue-rich states. In addition it provides information on the nature of the pomeron. We have ... More
Presented by Ms. Maria ZUREK on 5 Oct 2015 at 16:50
Type: Oral Presentation Session: Astroparticle Physics
Track: Astroparticle Physics
Cosmic Rays above 10^17 eV allow studying hadronic interactions at energies that can not be attained at accelerators yet. At the same time hadronic interaction models have to be applied to the cosmic-ray induced air-shower cascades in atmosphere to infer the nature of cosmic rays. The reliability of air-shower simulations has become the source of one of the largest systematic uncertainty in the ... More
Presented by Prof. Mario BERTAINA on 6 Oct 2015 at 10:50
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
I shall report the recently published paper [PLB748(2015)9], written together with Wojtek Florkowski and Kacper Zalewski. Starting from the observation that the composite nature of hadrons implies space-time correlations between produced particles, we studied consequences of this effect for the Bose-Einstein correlation function of identical particles. The expected magnitude of these effects is ... More
Presented by andrzej BIALAS on 5 Oct 2015 at 11:24
Type: Oral Presentation Session: First Results from LHC Run II
Track: First Results from LHC Run II
An overview of the first Run II results from CMS, including 13 TeV measurements of dN/deta of charged hadrons, the dijet ridge, inclusive ttbar and single top production among others.
Presented by Dr. Ferenc SIKLÉR on 9 Oct 2015 at 09:00
Type: Oral Presentation Session: First Results from LHC Run II
Track: First Results from LHC Run II
By using the very first Run II LHC data LHCb measured the cross-sections for quarkonia, beauty and charm productions. Results exploits the new "Turbo" stream procedure allowing the analysis of particle candidates selected at trigger level without the need of offline reconstruction. First results are presented.
Presented by Tomasz SZUMLAK on 9 Oct 2015 at 11:50
Type: Oral Presentation Session: First Results from LHC Run II
Track: First Results from LHC Run II
The ALICE Collaboration is collecting data with both Minimum Bias and Muon triggers with pp collisions at sqrt(s) = 13 TeV in the ongoing LHC Run II. An excellent performance of tracking and PID in the central barrel and in the muon spectrometer has been obtained. First results on the charged-particle pseudorapidity density and on identified particle transverse momentum spectra at 13 TeV will be p ... More
Presented by Dr. Alberica TOIA on 9 Oct 2015 at 11:10
Type: Poster Session: Poster session
Track: High Energy and High Pt Interactions
We present a new scheme for tagging b-jets with p_T > 500 GeV called "mu_x tagging." At the LHC, the primary method to tag b-jets relies on tracking their charged constituents. However, when highly boosted, track-based b-tags lose efficiency, and the probability to mistag light jets rises dramatically. Using muons from B hadron decay and defining a particular combination "x" of angular informat ... More
Presented by Prof. Zack SULLIVAN on 5 Oct 2015 at 18:40
Type: Poster Session: Poster session
Track: Collective Phenomena in High Energy Collisions
Temperature fluctuations may have two distinct origins, first, quantum fluctuations that are initial state fluctuations, and second, thermodynamical fluctuations. We discuss a method of extracting the thermodynamic temperature from the mean transverse momentum of pions, by using controllable parameters such as centrality of the system, and range of the transverse momenta. Event-by-event fluctuatio ... More
Presented by Mr. Sumit BASU on 5 Oct 2015 at 19:55
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
The uncertainties of protons parton distribution functions (PDFs) play a dominant role for the precision tests of the Standard Model (SM) and they also impact substantially the theory predictions of Beyond SM high mass production. We present theHERAFitter project which provides a unique open-source software framework for the determination of the proton's PDFs and for the interpretation of the phy ... More
Presented by Hayk PIRUMOV on 8 Oct 2015 at 16:05
Type: Poster Track: Collective Phenomena in High Energy Collisions
Hadronic resonances are used to study the properties of the strongly interacting hot and dense matter produced in ultra-relativistic heavy-ion collisions. The medium produced in such collisions evolves through different stages, including an early partonic phase which is succeeded by a hadronic phase. Since resonance yields may be modified by rescattering and regeneration after hadronization, they ... More
Presented by Mr. Kishora NAYAK
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
We present a new model for hard diffraction in Pythia8. The model uses the Pomeron approach pioneered by Ingelman and Schlein, factorising the diffractive cross section into a Pomeron flux and a Pomeron PDF, with several choices for both implemented in Pythia8. The main feature of the model is that it allows for any Pythia8 hard process to be generated diffractively, and includes an option of re ... More
Presented by Ms. Christine RASMUSSEN on 5 Oct 2015 at 14:20
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
I will review progress in quark mass determinations from lattice QCD simulation, focusing on results for charm and bottom mass. These are of particular interest for precision Higgs studies. Recent determinations have achieved percent-level uncertainties with controlled systematics. Future prospects for these calculations will also be discussed.
Presented by Dr. Andrew LYTLE on 8 Oct 2015 at 09:25
Type: Oral Presentation Session: Astroparticle Physics
Track: Astroparticle Physics
The neutrino observatory IceCube is opening a new observational window to the Universe. IceCube, which has been constructed in the icecap at the South Pole, is taking data since Spring 2011 in full configuration. The first years of data reveled the existence of extremely high neutrinos at the PeV scale. The observed diffuse neutrino flux is with high probability of astrophysical origin. In ... More
Presented by Prof. Elisa RESCONI on 6 Oct 2015 at 13:15
Type: Poster Track: Collective Phenomena in High Energy Collisions
The ALICE Experiment at the Large Hadron Collider (LHC) provides excellent capabilities to study charmonium production at low transverse momentum ($p_\mathrm{T}$). At central ($|y|<0.9$) and forward rapidity ($2.5<y<4$), J$/\psi$ are reconstructed via their leptonic decay channels down to $p_\mathrm{T}$ = 0. We will present ALICE results on the inclusive J$/\psi$ nuclear modification factor $R_\ma ... More Presented by Dr. Julian BOOK Type: Poster Track: High Energy and High Pt Interactions 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 Prof. Dick GREENWOOD Type: Poster Session: Poster session Track: Status of QCD In this talk I present the computer implementation of a general framework for NNLO calculations using the ColorFul NNLO subtraction scheme. This implementation identifies all singular regions automatically, assigns counter terms to them and if equipped with a phase space integrator, provides predictions for any IR-safe differential observable. The numerical framework will be illustrated ... More Presented by Dr. Adam KARDOS on 5 Oct 2015 at 18:35 Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions Track: Collective Phenomena in High Energy Collisions Proton-lead and lead-proton data taking during 2013 has allowed LHCb to expand its physics program to heavy ion physics. Results include the first forward measurement of Z production in proton-lead collisions as well as a measurement of the nuclear modification factor and forward-backward production of prompt and displaced J/psis, Psi(2S) and Upsilons. Angular particle correlations have als ... More Presented by Laure Marie MASSACRIER on 7 Oct 2015 at 11:30 Type: Oral Presentation Session: High Energy and High Pt Interactions Track: High Energy and High Pt Interactions In proton-proton collisions at the LHC, pairs of top and anti-top quarks are expected to be mostly produced through gluon fusion and the large number of ttbar pairs can be used to test the predictions of Quantum Chromodynamics. Measurements of the top quark production cross sections in proton-proton collisions at 7 and 8 TeV with the ATLAS and CMS detectors at the Large Hadron Collider are pr ... More Presented by Prof. Enrico TASSI on 6 Oct 2015 at 14:45 Type: Oral Presentation Session: Diffraction and Pomeron Track: Diffraction and Pomeron The ATLAS collaboration has carried out a study diffractive dijet production at 7 TeV pp collisions at the LHC, i.e. events with a hadronic system containing at least two jets in addition to a large region of pseudorapidity devoid of hadronic activity. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region wi ... More Presented by Grzegorz GACH on 5 Oct 2015 at 14:00 Type: Oral Presentation Session: High Energy and High Pt Interactions Track: High Energy and High Pt Interactions A study of QCD coherence is presented based on a sample of about 397,000 e+e- hadronic annihilation events collected at sqrt{s} = 91 GeV with the OPAL detector at LEP. The study is based on four recently proposed observables that are sensitive to coherence effects in the perturbative regime. The measurement of these observables is presented, along with a comparison with the predictions of differen ... More Presented by Dr. Stefan KLUTH, Stefan GIESEKE on 6 Oct 2015 at 14:00 Type: Oral Presentation Session: Proton Structure from ep and pp Track: Proton Structure from ep and pp Inclusive hadron production cross sections and angular distributions in e+e- collisions shed light on fundamental questions of hadronization and fragmentation processes. We present measurements of the Collins azimuthal asymmetries in inclusive production of hadron pairs, in the e+e- -> h1 h2 X annihilation process, where the hadrons (either kaons or pions) are produced in opposite hemispheres. ... More Presented by Alessandra FILIPPI on 8 Oct 2015 at 17:05 Type: Oral Presentation Session: Astroparticle Physics Track: Astroparticle Physics The muon content of extensive air showers produced by the ultra-high energy cosmic rays is an observable sensitive to the composition of the primary particle and to the properties of hadronic interactions driving the air-shower cascade. We present different methods to estimate the muon number at the ground and the muon production depth using measurements of the longitudinal, lateral, and temporal ... More Presented by Dr. Darko VEBERIC on 6 Oct 2015 at 12:35 Type: Oral Presentation Session: Astroparticle Physics Track: Astroparticle Physics Many LHC measurements have already been used to improve hadronic interaction models and thus lowered the model dependence of cosmic ray data analyses. However, the LHC still has a lot more potential to provide crucial information, which has not been fully exploited so far. Since the start of Run2 the highest accelerator beam energies are reached and no further increase can be expected for a long t ... More Presented by Ralf ULRICH on 6 Oct 2015 at 11:15 Type: Oral Presentation Session: High Energy and High Pt Interactions Track: High Energy and High Pt Interactions The production of vector bosons (V = W, Z or ?) in association with jets is a stringent test of perturbative QCD and is a background process in searches for new physics. The differential cross-section measurements measurements from CMS and ATLAS collaborations would be presented. The multijet topologies and event shape variables represent a particular interest to test multi-leg LO and NL ... More Presented by Mr. Vieri CANDELISE on 6 Oct 2015 at 16:30 Type: Oral Presentation Session: Astroparticle Physics Track: Astroparticle Physics Detecting Ultra High Energies Cosmic Rays (UHECRs) enables us to measure the proton-air inelastic cross section$\sigma^{\rm inel}_{\rm p-air}$at energies that we are unable to access with particle accelerators. The proton-proton cross section$\sigma_{\rm p-p}\$ is subsequently inferred from the proton-air cross section at these energies. UHECRs experiments have been reporting on the proton-air i ... More
Presented by Dr. Rasha ABBASI on 6 Oct 2015 at 12:55
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
The measurement of identified particle production rates as a function of event activity in small colliding systems has recently become of particular interest in understanding how observations performed in these systems relate to the much larger ones created in Pb-Pb collisions. Strangeness production may provide a valuable tool to probe changes in particle production mechanisms. We report on meas ... More
Presented by Dr. Rafael DERRADI DE SOUZA on 7 Oct 2015 at 09:20
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
New results of two- and multi-particle correlations in pp and pPb collisions will be presented. The measurements are performed as a function of multiplicity. In very-high-multiplicity events, a long-range near-side two-particle correlation is observed. Azimuthal anisotropy harmonics (v_n) are extracted as a function of eta, pT and multiplicity, using two- and multi-particle correlations. Identifie ... More
Presented by Zhenyu CHEN on 7 Oct 2015 at 11:10
Type: Poster Session: Poster session
Track: Collective Phenomena in High Energy Collisions
Using the color dipole formalism we study production of direct photons and Drell-Yan pairs in pA interactions. Real photons and lepton pairs produced in a hard scattering are not accompanied with any final state interaction, either energy loss or absorption. Consequently, the associated observables may serve as more efficient and cleaner probes for nuclear modification effects than inclusive hadro ... More
Presented by Dr. Victor GONCALVES on 5 Oct 2015 at 19:40
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
The energy dependence of the strength parameter also called the chaoticity, derived from Bose-Einstein correlations (BEC) of pion-pairs produced in proton-proton collisions is investigated. Considered are the one and three dimensions (1D, 3D) of the BEC analyzed in terms of a Gaussian and / or exponential distributions. A marked difference is observed between the dependence of the chaoticity on en ... More
Presented by Prof. Gideon ALEXANDER, Prof. Vitalii OKOROKOV
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
This talk gives an overview of QCD measurements at high pT at the LHC and other colliders. Recent results on inclusive jet, dijet and multijet production measurements are presented together with results of alpha_S extraction and constraints on the PDFs of the proton. Precision measurements of vector bosons (V = W, Z or γ) in association with jets allow for stringent tests of perturbative QCD. The ... More
Presented by Matthias WEBER on 8 Oct 2015 at 11:25
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
Quarkonium has been regarded as one of the golden probes for the deconfined phase transition to the quark-gluon plasma (QGP) since late 80's when the relativistic heavy-ion experiments started at AGS and SPS. The heavy quarkonia can be generated in gluon-gluon scatterings at early stage of the collision as the large momentum transfer is required. Later the binding potential between a quark and ... More
Presented by Prof. Byungsik HONG on 7 Oct 2015 at 10:00
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
Recent results on PDF constraints and alpha_s from CMS are presented
Presented by Dr. Maxime GOUZEVITCH on 8 Oct 2015 at 14:45
Type: Poster Session: Poster session
Track: Status of QCD
The spectroscopy of exotics states with hidden charm together with the spectroscopy of charmed and stranged baryons is discussed. It is a good testing tool for the theories of strong interactions, including: QCD in both the perturbative and non-perturbative regimes, LQCD, potential models and phenomenological models. An understanding of the baryon spectrum is one of the primary goals of non-pertur ... More
Presented by Dr. Mikhail BARABANOV on 5 Oct 2015 at 19:15
Type: Poster Session: Poster session
Track: Collective Phenomena in High Energy Collisions
The statistical hadronization (or thermal) model yields good results when compared to e.g. hadron production rates in LHC heavy-ion data. However, the distribution functions in p_T, rapidity y and eta clearly show deviations from thermal behaviour. Such non-equilibrium effects can to a certain extent be accounted for in a relativistic diffusion model with three sources - two fragmentation sour ... More
Presented by Prof. Georg WOLSCHIN on 5 Oct 2015 at 19:30
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
An overview on the new parton distribution functions (PDFs) up to next-to-next-to-leading order (NNLO) from the CTEQ-TEA global analysis of quantum chromodynamics will be given. Predictions for important LHC processes, especially Higgs boson and top-quark pair production at 7, 8, 13 TeV, will be presented, and main features and impact of CT14 PDFs on LHC physics will be discussed.
Presented by Dr. Marco GUZZI on 8 Oct 2015 at 10:15
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
Isolated prompt photons provide a direct probe of short- distance physics, complementary to that provided by measurements of jets or vector-bosons and are sensitive to the gluon density of the proton. The inclusive prompt photon cross sections have been measured by the ATLAS collaboration at various centre-of-mass energies of pp collisions over a wide range of transverse momenta. These experi ... More
Presented by Prof. Claudia GLASMAN on 8 Oct 2015 at 14:00
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
A simple quantization concept for a 3-dim QCD string is used to derive properties of QCD flux tube from the mass spectrum of light mesons and to predict observable quantum effects in correlations between adjacent hadrons. The quantized fragmentation model is presented and compared with experimental observations.
Presented by Dr. Sharka TODOROVA-NOVA on 5 Oct 2015 at 11:40
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
Recent CMS results regarding forward physics and diffraction are reviewed. The differential diffractive cross section is measured as a function of xi= M_X^2/s in the region dominated by single dissociation (SD) and double dissociation (DD), where M_X is the mass of one of the two final-state hadronic systems separated by the largest rapidity gap in the event. The cross section is also measured as ... More
Presented by Dr. Gabor VERES on 5 Oct 2015 at 14:35
Type: Oral Presentation Session: High Energy and High Pt Interactions
Track: High Energy and High Pt Interactions
With Run II of the LHC having started, the need for high precision theory predictions whose uncertainty matches that of the data to be taken necessitated a rage of new developments in Monte-Carlo Event Generators. In this talk I will give an overview of the progress in recent years in the field and what can and cannot be expected from these newly written tools.
Presented by Marek SCHOENHERR on 6 Oct 2015 at 14:20
The exclusive dijet production in diffractive deep inelastic e+- p scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 372 pb^{-1}. The measurement was performed for \gamma^*-p centre-of-mass energies in the range 90 < W < 250 GeV and photon virtualities in the range Q^2 > 25 GeV^2. Energy and transverse-energy flows around the jet axis are presented. The ... More
Presented by Dr. Alice VALKAROVA on 5 Oct 2015 at 17:10
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
The current PDF4LHC recommendation to estimate uncertainties due to parton distribution functions (PDFs) in theoretical predictions for LHC processes involves the combination of separate predictions computed using PDF sets from different groups, each of which comprises a relatively large number of either Hessian eigenvectors or Monte Carlo (MC) replicas. We present a strategy for the statisti ... More
Presented by Dr. Andy BUCKLEY on 8 Oct 2015 at 16:25
Type: Oral Presentation Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
I will review recent progress in exclusive production of mesons and dileptons in proton-proton collisions. This includes exclusive production of J/psi, psi' and rho^0 mesons as well as production of two pions, two leptons, two photons or two charged Higgs bosons. In the case of the charmonia a k_t-factorization method with unintegrated gluon distributions is applied. A possible sign of the ... More
Presented by Prof. Antoni SZCZUREK
Session: Diffraction and Pomeron
Track: Diffraction and Pomeron
I will review recent progress in exclusive production of mesons and dileptons in proton-proton collisions. This includes exclusive production of J/psi, psi' and rho^0 mesons as well as production of two pions, two leptons, two photons or two charged Higgs bosons. In the case of the charmonia a k_t-factorization method with unintegrated gluon distributions is applied. A possible sign of the ... More
Presented by Prof. Antoni SZCZUREK on 5 Oct 2015 at 16:15
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
The aim of the NA61/SHINE ion programme is to explore the phase diagram of strongly interacting matter. The main physics goals are the study of the onset of deconfinement and the search for the critical point of strongly interacting matter. These goals are pursued by performing an beam momentum (13A - 158A GeV/c) and system size (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La) scan. This contribution reviews r ... More
Presented by Mr. Emil KAPTUR on 7 Oct 2015 at 09:40
Type: Oral Presentation Track: Collective Phenomena in High Energy Collisions
Measurements of soft particle production have provided valuable insight on properties of the evolution of the quark-gluon plasma in Pb+Pb collisions at the LHC. In particular, measurements of flow harmonics using the azimuthal angle distributions of low-pT particles directly test hydrodynamic model descriptions of its evolution. The large acceptance of the ATLAS detector enables the measurement of ... More
Presented by Prof. Dick GREENWOOD
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
We give an overview of recent results on hadron structure observables using lattice QCD simulations with physical values of the quark masses.
Presented by Alexandrou CONSTANTIA on 8 Oct 2015 at 09:50
Type: Poster Session: Poster session
Track: Status of QCD
The BABAR Collaboration has an extensive program of studying hadronic cross sections in e+e- collisions at low-energies, which are accessible at center-of-mass energy of about 10.6 GeV via initial-state radiation. Our measurements allow significant improvements in the precision of the predicted value of the muon anomalous magnetic moment. We report here the most recent results on several processes ... More
Presented by fabio ANULLI on 5 Oct 2015 at 18:55
Session: Poster session
Track: Collective Phenomena in High Energy Collisions
Starting from the Boltzmann equation in the relaxation time approximation and employing a Chapman-Enskog like expansion for the distribution function close to equilibrium, we derive second-order evolution equations for the shear stress tensor and the dissipative charge current for a system of massless quarks and gluons. The transport coefficients are obtained exactly using quantum statistics for t ... More
Presented by Dr. Amaresh JAISWAL on 5 Oct 2015 at 19:50
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
Measurements of the properties of charged particle production are presented from proton-proton collisions at different centre-of-mass energies in the range of 0.9 to 13 TeV and compared to various Monte Carlo event generator models. Furthermore particle distributions sensitive to the underlying event in proton-proton collisions have been measured and are compared to theoretical models. The p ... More
Presented by Yuri KOULTCHITSKI on 5 Oct 2015 at 09:15
Type: Oral Presentation Session: High Energy and High Pt Interactions
Track: High Energy and High Pt Interactions
This talk will provide a summary of progress in the resummation of observables for hadron colliders, focusing in particular on event shape observables. Event shapes and jet rates are invaluable QCD tools for theoretical calculations and experimental measurements. I will revise the definition of these observables in hadron collisions, and give a review of the state-of-the-art results for their resu ... More
Presented by Ms. Heather MCASLAN on 6 Oct 2015 at 16:55
Type: Oral Presentation Session: High Energy and High Pt Interactions
Track: High Energy and High Pt Interactions
Signals of QCD instanton-induced processes are searched for in deep-inelastic scattering (DIS) at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable x > 10^{-3}, the inelasticity 0.2< y < 0.7 and the photon virtuality 150 < Q^2 < 15000 GeV^2. The search is performed using H1 data corresponding to an integrated luminosity of ~350 pb^{-1}. Several obser ... More
Presented by Dr. Hayk PIRUMOV on 6 Oct 2015 at 17:45
Type: Oral Presentation Session: Astroparticle Physics
Track: Astroparticle Physics
Searches for strongly produced dark matters in events with jets, photons, heavy-flavor quarks or massive gauge bosons recoiling against large missing transverse momentum in ATLAS are presented. These “MET+X” signatures provide powerful probes to dark matter production at the LHC, allowing us to interpret results in terms of effective field theory and/or simplified models with pair product ... More
Presented by Dr. Henso ABREU on 6 Oct 2015 at 10:30
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
Most signatures of new physics beyond the Standard Model have been studied on the transverse plane with respect to the beam direction. In this work we rather consider the effect of a hidden sector (i.e. Hidden Valley model) on rapidity correlations, moments and cumulants of multiplicity distributions in multiparticle production with an special emphasis in the prospects for the forthcoming LHC resu ... More
Presented by Prof. Miguel-Angel SANCHIS-LOZANO on 5 Oct 2015 at 10:22
Type: Poster Track: Collective Phenomena in High Energy Collisions
First results of soft photon study in nuclear interactions at 3.5 GeV per nucleon are presented. These photons have been registered at Nuclotron (LHEP, JINR) by an electromagnetic calorimeter built of SVD Collaboration. The obtained spectra confirm the excess yield in the energy region less than 50 MeV in comparison with theoretical predictions and agree with previous experiments at high-energy i ... More
Presented by Dr. Elena KOKOULINA
Type: Poster Session: Poster session
Track: Astroparticle Physics
The CUORE experiment, expected to start operations in early 2016, will search for neutrinoless double beta decay of 130Te and will be one of the most competitive neutrinoless double beta decay experiments in the near future. Its demonstrator (CUORE-0) has reported in 2015 no evidence for neutrinoless double-beta decay and placed a lower bound on the decay half-life, T(0ν)1/2>2.7×10^24 yr at 90% ... More
Presented by Mr. Niccolo MOGGI on 5 Oct 2015 at 18:50
Type: Poster Track: Collective Phenomena in High Energy Collisions
The study of strange and multi-strange particle production in high-energy collisions of heavy nuclei is considered as as unique tool to investigate the properties of the hot and dense matter created in the course of collision. These processes are sensitive to the reaction dynamics, as there is no net strangeness content in the initial state of colliding nuclei. In particular, an enhanced productio ... More
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
For the first time we investigate non-equilibrium dynamic properties of a plasma consisting of confining gluons resulting from Gribov quantization [1]. For this purpose we employ the infrared-improved Gribov dispersion relation of gluons in the kinetic theory setup in the relaxation time approximation and determine the exact in- and out-of-equilibrium evolution of the system. In the static case t ... More
Presented by Wojciech FLORKOWSKI on 7 Oct 2015 at 10:20
Type: Oral Presentation Session: Proton Structure from ep and pp
Track: Proton Structure from ep and pp
Several measurements performed by the ATLAS collaboration are either useful to constrain the proton structure or are affected by its associated uncertainties. Measurements of the W+c production and the inclusive W and Z differential cross sections are found to constrain the poorly known strange-quark density at low x. Similarly, the ratio of W+/W- production is found to constrain the valence ... More
Presented by Dr. Peter BUSSEY on 8 Oct 2015 at 15:10
Type: Oral Presentation Session: High Energy and High Pt Interactions
Track: High Energy and High Pt Interactions
Several aspects of jet production in pp collisions have been measured by the ATLAS and CMS collaborations. The jet production cross sections probe the dynamics of QCD and can constrain the parton proton structure. Double-differential cross sections for inclusive, di-, three- and four-jet final states are measured at different centre-of-mass energies of pp collisions with the ATLAS detector and ar ... More
Presented by Mr. Nuno ANJOS on 6 Oct 2015 at 17:20
Type: Poster Track: High Energy and High Pt Interactions
We report on recent searches for baryonic B decays using the whole BABAR dataset of 471 million B anti-B pairs. Although about 7% of all B decays have baryons in the final state, known exclusive decay modes account for only about 10% of these decays, and very little is known about the mechanism of baryon production in weak decays or in the hadronization process. By studing such decays we can ... More
Presented by fabio ANULLI
Type: Poster Track: Collective Phenomena in High Energy Collisions
The hydro-dynamics inspired thermal approach - Blast-Wave (BW) model - implemented with non-extensive Tsallis statistics (TBW) has gained increasing interest in heavy-ion physics. With the come out of recent LHC results on particle production of various species, it is a good opportunity to use this approach to interpret the data. The pT spectra, from both p+p and Pb+Pb collisions, are systematical ... More
Presented by Dr. Zebo TANG
Type: Poster Session: Poster session
Track: Status of QCD
We present a new measurement of BBbar hadron production at the LHC using the inclusive decay modes B(Bbar)->Jpsi+X->mumu+X and Bbar(B)- >mu+X. Using this three muon final state differential cross sections are presented, giving new constraints on B hadron production kinematics in particular at small separation angles between the bb~ pair. Further corrections are also determined to allow theory ... More
Presented by Prof. Dick GREENWOOD on 5 Oct 2015 at 19:10
Type: Oral Presentation Session: High Energy and High Pt Interactions
Track: High Energy and High Pt Interactions
Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent ATLAS and CMS results for searches for supersymmetric (SUSY) particles, with an emphasis on strong production in both R-Parity conserving and R-Parity violating SUSY scenarios. The searches involve final states including jets, m ... More
Presented by Sascha CARON on 6 Oct 2015 at 15:10
Type: Poster Session: Poster session
Track: Collective Phenomena in High Energy Collisions
We investigate nuclear effects in production of Drell-Yan pairs and direct photons in proton-nucleus collisions. For the first time, these effects are studied within the color dipole approach using the Green function formalism which naturally incorporates the color transparency and quantum coherence effects. Numerical results for the nuclear modification factor are compared with available data. Be ... More
Presented by Mr. Michal KRELINA on 5 Oct 2015 at 19:35
Type: Oral Presentation Session: Status of QCD
Track: Status of QCD
A preliminary preview will be given on the recent update of alpha_s measurements and the new world average value of alpha_s(M_z), which is currently prepared for the 2015 edition of PDG's Review of Particle Properties.
Presented by Prof. S. BETHKE on 8 Oct 2015 at 12:15
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
The two-particle correlation at small relative momenta is influenced by the nuclear force between two particles, which has been intensively studied for nucleons or nuclei but not much for anti-nucleons or anti-nuclei. In this talk, we present the (anti)proton-(anti)proton correlation function in Au+Au collisions at \sqrt{s_{NN}} = 200 GeV based on data taken by the STAR experiment at RHIC. We show ... More
Presented by Mr. ZHENGQIAO ZHANG on 5 Oct 2015 at 10:06
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
Some new results concerning the tau-model of Bose-Einstein correlations will be presented.
Presented by Dr. Wesley METZGER on 5 Oct 2015 at 11:08
Type: Poster Session: Poster session
Track: Multiparticle Correlations and Fluctuations
A new distribution is obtained from the Generalised Multiplicity Distribution (GMD). This distribution is derived by a weighted sum of the GMD over the initial number of gluons, removing the dependence of the model on a specific initial state for QCD evolution. The distribution is shown to describe multiplicity data at various LHC energies, possibly providing information on gluon production. Compa ... More
Presented by Mr. Wei Yang WANG on 5 Oct 2015 at 19:20
Type: Oral Presentation Session: Astroparticle Physics
Track: Astroparticle Physics
IceCube telescope has detected ~TeV-PeV neutrinos of astrophysical origin. Currently, their origin is still unknown. In this talk, we will review the main recent theoretical explanations for these high-energy neutrinos. Both scenarios of a Galactic origin (such as the Fermi bubbles, cosmic rays in the halo, or other Galactic sources) and of an extragalactic origin (such as active galactic nuclei, ... More
Presented by Dr. Gwenael GIACINTI on 6 Oct 2015 at 13:35
Session: Status of QCD
Presented by Prof. Andre HOANG on 8 Oct 2015 at 11:00
Type: Poster Session: Poster session
Track: Collective Phenomena in High Energy Collisions
The transverse momentum spectra of hadrons produced in high energy collisions can be decomposed into the two components: the exponential ("thermal") and the power ("hard") ones. Thus, charged hadron spectra produced in proton-proton and heavy-ion collisions from ISR to LHC are considered simultaneously within this model. The parameters of the model are found to vary with the type of the collision, ... More
Presented by Dr. Alexander BYLINKIN on 5 Oct 2015 at 19:45
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
The underlying event activity in pp collisions, measured using events with a leading charged particle or a leading charged particle jet, lends credence to multiparton interactions. The activity is measured independently in the two halves of the region transverse to the leading object, containing the maximum and minimum activities. Complementary to the underlying event analysis, the observation of ... More
Presented by Mr. Wei Yang WANG on 5 Oct 2015 at 09:32
Type: Oral Presentation Session: Multiparticle Correlations and Fluctuations
Track: Multiparticle Correlations and Fluctuations
Universality of multihadron production in AA and hadronic interactions is studied using collision energy and centrality dependencies of the measured charged particle mean multiplicity. The study uses the framework of an effective-energy approach combining the constituent quark picture and Landau relativistic hydrodynamics and relating hadronic and nuclear collisions. The energy dependence of the m ... More
Presented by Dr. Raghunath SAHOO, Mr. Aditya Nath MISHRA on 5 Oct 2015 at 12:12
Session: Status of QCD
Presented by Prof. Siggi BETHKE
Type: Oral Presentation Session: Collective Phenomena in High Energy Collisions
Track: Collective Phenomena in High Energy Collisions
Recent observations of ridge-like structure in p-p and p-A angular correlations at the RHIC and LHC are interpreted to imply collective motion in smaller systems. It is argued that if correlations representing flows in A-A collisions appear in smaller systems collectivity must extend to the smaller systems. But the argument could be reversed to conclude that such structures appearing in A-A collis ... More
Presented by Prof. Thomas TRAINOR on 7 Oct 2015 at 12:10