Francois Gelis
(IPhT Saclay)
5/22/11, 9:00 AM
Paul Romatschke
(Frankfurt Institute for Advanced Studies)
5/22/11, 9:50 AM
Marco van Leeuwen
(Utrecht University)
5/22/11, 11:00 AM
Roberta Arnaldi
(Universita degli Studi di Torino)
5/22/11, 11:40 AM
David d'Enterria
(CERN)
5/22/11, 2:00 PM
Dr
Panos Christakoglou
(NIKHEF - Utrecht University)
5/22/11, 2:15 PM
Konrad TYWONIUK
(University of Lund)
5/22/11, 2:30 PM
Agnes Mocsy
(Pratt Institute, NY, USA)
5/22/11, 2:45 PM
Dr
Stefan Bathe
(RIKEN-BNL Research Center)
5/23/11, 10:40 AM
Plenary
After establishing the creation of dense partonic matter in the early
years of RHIC, the focus of recent experimental and theoretical effort
has been to determine the properties of this partonic medium. With
the advent of the LHC, there is now a new aspect to this quest:
are the properties of the medium created at the LHC different from that
created at RHIC? In this light, we...
Juergen Schukraft
(CERN)
5/23/11, 11:30 AM
Plenary
In this talk we summarize the results obtained by ALICE Collaboration in the first Pb-Pb run at LHC.
Peter Steinberg
(Brookhaven National Laboratory)
5/23/11, 11:55 AM
Plenary
Bolek Wyslouch
(MIT)
5/23/11, 12:20 PM
Plenary
We will present early results of the CMS experiment from PbPb collisions at
√sNN = 2.76 TeV, probing quark and gluon matter at unprecedented
values of energy density. The capabilities of the CMS apparatus allows us to
investigate various hard probes, as well as bulk particle production and
collective phenomena, using the calorimetry, muon and tracking systems covering
a large range in...
Prof.
Dmitri Kharzeev
(Stony Brook and BNL)
5/23/11, 3:00 PM
An overview of the recent progress in understanding the interplay of
quantum anomalies, chirality, and magnetic field in the dynamics
of QCD fluid will be presented. The current theoretical description
of the chiral magnetic and chiral vortical effects within anomalous
magnetohydrodynamics will be described. It allows a quantitative
approach to these phenomena in heavy ion...
Edward Shuryak
(Stony Brook University)
5/23/11, 3:00 PM
Recently there was significant progress in account for several lower
harmonics of the ``Little Bang", especially the so called triangular flow,
ascribed to fluctuations of the initial conditions. We discuss this
problem more generally, combining many harmonics coherently into
certain patterns of sound propagation. Analytic solution for all harmonics
is found for the so called ``Gubser...
Constantinos Loizides
(Lawrence Berkeley National Lab. (LBNL))
5/23/11, 3:20 PM
The measurements of charged-particle multiplicity and transverse energy
in Pb-Pb collisions at 2.76 ATeV are reported as a function of centrality. The fraction of inelastic cross section seen by the ALICE detector is estimated using a Glauber model or correcting the data by simulations. The results scaled by the number of participating nucleons are compared with pp collisions at the same...
Berndt Mueller
(Duke University)
5/23/11, 3:20 PM
Using the AdS/CFT correspondence, we probe the scale-dependence of thermalization in strongly coupled field theories following a quench, via calculations of 2-point functions, Wilson loops and entanglement entropy in 2, 3, and 4 dimensions. In the saddlepoint approximation these probes are computed in AdS space in terms of invariant geometric objects -- geodesics, minimal surfaces and...
Alexander Philipp Kalweit
(Technische Universität Darmstadt)
5/23/11, 3:20 PM
The particle identification capabilities of the ALICE experiment are unique among the four major LHC experiments. The working principles, the strategies for signal extraction, and excellent performance of the central barrel detectors in a high-multiplicity environment will be presented. The particle identification of the Inner Tracking System (ITS) and the Time Projection Chamber (TPC) are...
Dr
Yoshitaka Hatta
(University of Tsukuba)
5/23/11, 3:40 PM
It has been argued that high-multiplicity proton-proton collisions at the LHC may exhibit collective phenomena usually studied in the context of heavy-ion collisions, such as elliptic flow. We study this issue using DIPSY, a brand-new Monte Carlo event generator which features almost-NLL BFKL dynamics and describes the transverse shape of the proton including all fluctuations. We predict the...
Dr
Jorge Casalderrey Solana
(CERN)
5/23/11, 3:40 PM
The recent results at the LHC on jet quenching in heavy ion
collisions call for a
fundamental understanding of the evolution of a relatively hard jet
propagating through a QCD medium like the quark--gluon plasma. As a first
step in that sense, we consider the interference pattern for the
medium--induced gluon radiation produced by a color singlet
quark--antiquark antenna embedded in a...
Marek Chojnacki
(UU/NIKHEF)
5/23/11, 3:40 PM
The ALICE experiment features several particle
identification systems, which allow us to measure spectra in a broad range of transverse momentum $p_{\mathrm{t}}$ from 100 MeV/c up to a few GeV/c.
New results on identified charged particle $p_{\mathrm{t}}$ spectra measured in proton-proton collisions at $\sqrt{s}=7$ TeV will be presented.
They will be compared to results obtained at 900...
Krisztian Krajczar
(KFKI Research Institute for Particle and Nuclear Physics of the Hungarian Academy of Sciences)
5/23/11, 3:40 PM
The pseudorapidity and centrality dependence of transverse energy and charged particle multiplicities offers insight into the properties of the matter produced in the collisions of ultra-relativistic heavy nuclei. Multiplicities as a function of center-of-mass energy and collision centrality are important for exploring the role of hard and soft scattering in particle production and for looking...
Terence Tarnowsky
(Michigan State University)
5/23/11, 4:00 PM
Terence J Tarnowsky (for the STAR Collaboration)
Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. Results from new measurements of dynamical $K/\pi$, $p/\pi$, and $K/p$ ratio fluctuations are presented. The commencing of a QCD critical point search at RHIC has extended the reach of possible...
Dr
Yacine Mehtar-Tani
(University of Santiago de Compostela)
5/23/11, 4:00 PM
Jet physics in hadronic collisions is one of the major achievements of perturbative QCD. However, a complete theory of jets in a hot and dense partonic environment remains to be developed. Such a theory is needed in Heavy-Ion Collisions (HIC), at RHIC and now at the LHC, in order to have a clean access to the properties of the Quark-Gluon Plasma (QGP).
To this end, we have investigated...
Yujiao Chen
(Columbia University)
5/23/11, 4:00 PM
Charged particle multiplicity is an important bulk observable for heavy ion collisions. It measures the global features of the medium produced and constrains the initial conditions of the system. It also provides an important test for dynamical model calculations which predict the dependence of multiplicity on centrality at RHIC and the LHC. We present the study of charged particle...
Reinhard Stock
(Institut fuer Kernphysik - Johann-Wolfgang-Goethe Univ.)
5/23/11, 4:00 PM
In nucleus-nucleus collisions we distinguish early hadro-chemical freeze-out, fixing hadronic concentrations, and final kinetic freeze-out to spectral and flow features, occuring at the end of the hadronic "cascade" phase. This view has been adopted in all recent analysis of hadron production rates, which are well described in the grand canonical statistical equilibrium model. The derived...
Dr
Jean-Yves Ollitrault
(SPhT, Saclay)
5/23/11, 4:20 PM
Long-range azimuthal correlations are generated by fluctuations of the
initial energy distribution, followed by collective flow.
We list eight independent observables which can be measured using
multiparticle azimuthal correlations in the first three Fourier
harmonics. Some of these observables are already well known, such as
$v_2\{2\}$ and $v_2\{4\}$, but most of them are new, in...
Dr
Klaus Reygers
(University of Heidelberg)
5/23/11, 4:20 PM
The inclusive production of $\pi^0$ and $\eta$ mesons is measured at mid-rapidity in pp collisions over a wide transverse momentum ($p_T$) range with the ALICE experiment at $\sqrt{s}$=900GeV, 2.76~TeV and 7~TeV. The mesons are measured via two different techniques: with the calorimeters (PHOS and EMCAL) and via photon conversions reconstructed in the Central Tracking System.
A systematic...
Prof.
Yuri Kovchegov
(The Ohio State University)
5/23/11, 4:20 PM
We calculate running coupling corrections for the lowest-order gluon production cross section in high energy hadronic and nuclear scattering using the BLM scale-setting prescription. In the final answer for the cross section the three powers of fixed coupling are replaced by seven factors of running coupling, five in the numerator and two in the denominator, forming a 'septumvirate' of running...
Piotr Bozek
(IFJ PAN Krakow/ Rzeszow University)
5/23/11, 4:20 PM
The expansion of the fireball created in Pb-Pb collisions at $\sqrt{s}=2.76$TeV is modelled using the relativistic viscous hydrodynamics. The experimentally observed interferometry radii are well reproduced. The recent data of the ALICE Collaboration on the elliptic flow as function of the centrality can be very well described using the hydrodynamic expansion of a fluid with a small shear...
Dr
Martin Poghosyan
(Universita & INFN, Torino)
5/23/11, 4:40 PM
(for the ALICE Collaboration)
The relative rates of single‐ and double‐ diffractive processes were measured with the ALICE detector by studying properties of gaps in the pseudorapidity distribution of particles produced in proton‐proton collisions at \sqrt{s} = 0.9 TeV, 2.76 TeV and 7 TeV. ALICE triggering efficiencies were determined for various classes of events, using a detector...
Philippe Mota
(Institut für Theoretische Physik, Goethe-Universität)
5/23/11, 4:40 PM
We investigate the effect of event-by-event fluctuations and the degree of granularity in the initial conditions on the collective evolution of matter created in heavy-ion collisions using fluid dynamics. Motivated by the glasma-flux-tube scenario, we model the initial condition by a set of randomly distributed longitudinal tubes in a boost-invariant 2D geometry. The model introduces two...
Giovanni Antonio Chirilli
(Lawrence Berkeley National Laboratory (LBNL))
5/23/11, 4:40 PM
The high-energy behavior of amplitudes in gauge theories can be reformulated in terms
of the evolution of Wilson-line operators. In the leading order this evolution is governed by the non-linear Balitsky-Kovchegov (BK) equation.
In order to see if this equation is relevant for existing or future DIS accelerators
(like EIC or LeHC) one needs to know how large are the next-to-leading order...
Dr
Alberto Pulvirenti
(University / INFN Catania)
5/23/11, 4:40 PM
The study of resonances production in pp collisions contributes to the proper tuning of the QCD-inspired particle production models and to the better understanding of the underlying event, while in PbPb collisions resonances are good probes to estimate the collective properties of the fireball, and in particular its lifetime.
Strange resonances can also contribute to the historical topic of...
Iouri BELIKOV
(IPHC, CNRS-IN2P3)
5/23/11, 5:30 PM
We present the study of K0s and Lambda production performed with
the ALICE experiment at the LHC in Pb-Pb collisions at sqrt(sNN)=2.76 TeV and pp collisions at sqrt(s)=0.9 and 7 TeV.
The K0s and Lambda particles are reconstructed via their V0 decay
topology allowing their identification up to high transverse momenta.
The corresponding baryon/meson ratios as a function of transverse...
wenqin xu
(University of California Los Angeles)
5/23/11, 5:30 PM
FOR THE STAR COLLABORATION
Heavy Quarks are mostly produced through gluon fusions during the initial stage of the heavy ion collisions. Experimentally heavy quarks are found to suffer a considerable energy loss in the QCD medium with the nuclear modification factor for non-photonic electrons (NPE) from heavy quark decays much smaller than unity in central Au+Au collisions at RHIC. To better...
Chun Shen
(Ohio State University),
Ulrich Heinz
(The Ohio State University)
5/23/11, 5:30 PM
The last two years have seen tremendous progress in the theoretical tools for extracting the specific shear viscosity of the quark-gluon plasma in the temperature range explored by heavy-ion collisions at RHIC and LHC. The effects of viscosity on the transverse momentum spectra and differential elliptic flow and their interplay with other hydrodynamic parameters have been studied...
Jorge Mercado
(Heidelberg University)
5/23/11, 5:30 PM
We present the first measurement of pion source radii in Pb-Pb
collisions at the LHC. The radii were obtained by analyzing the
Bose-Einstein enhancement in two-pion correlation functions. Like at lower energies, the radii drop with increasing transverse momentum, indicating the presence of collective expansion. In absolute terms, all three radii (R_out, R_side, R_long) are larger than at...
439.
Charged hadron azimuthal anisotropy (v_2) in $sqrt s_{NN} = 2.76 $ TeV PbPb collisions from CMS
Victoria Zhukova
(University of Kansas)
5/23/11, 5:50 PM
During the past decade, azimuthal correlation measurements have played a pivotal role in our understanding of the properties of high density QCD matter through their sensitivity to the early stage evolution of relativistic heavy-ion collisions. Despite our increased understanding of the transport coefficients of the plasma produced in these collisions, there remain many questions concerning...
Sandra Padula
(Instituto de Fisica Teorica (IFT)-Universidade Estadual Paulista)
5/23/11, 5:50 PM
Bose--Einstein correlations between identical particles are measured in samples of proton-proton collisions at 0.9 and 7 TeV centre-of-mass energies, recorded by the CMS experiment at the LHC. The signal is observed in the form of an enhancement of number of pairs of same-sign charged particles with small relative momentum. The dependence of this enhancement on kinematic and topological...
D.D. Chinellato
(Instituto de Fisica Gleb Wataghin (IFGW) - Universidade Estadual de Campinas)
5/23/11, 5:50 PM
The production of charged multi-strange particles is studied with the ALICE experiment at the CERN LHC. Measurements of the central rapidity yields of $\Xi^{-}$ and $\Omega^{-}$ baryons, as well as their antiparticles, are presented as a function of transverse momentum ($p_{T}$) for inelastic pp collisions at $\sqrt{s}=7\:TeV$ and compared to existing measurements performed at the same and/or...
Xiaoming Zhang
(Laboratoire de Physique Corpusculaire, Clermont-Ferrand)
5/23/11, 5:50 PM
Heavy-quark production is one of the probes for the investigation of the properties
of the high-density medium formed in heavy-ion collisions. This investigation requires also the study of proton-proton collisions. Besides providing the necessary baseline for nucleus-nucleus collisions, proton-proton collisions are of great interest, also in their own right, since they allow to test...
Mikolaj Krzewicki
(NIKHEF)
5/23/11, 6:10 PM
The anisotropic flow of identified particles is an important observable to test the collective behavior of the matter created in heavy-ion collisions. We report on the first measurements of elliptic and triangular flow for charged pions, kaons and protons in lead-lead collisions at 2.76 TeV per nucleon pair center of mass energy, measured with the ALICE detector at the LHC.
We will make a...
Simone Schuchmann
(Institut fuer Kernphysik-Johann-Wolfgang-Goethe Univ.)
5/23/11, 6:10 PM
Significant suppression of unidentified charged particles at large transverse momentum has been observed in central Pb-Pb collisions at the LHC.
Measurements of identified particles will provide more detailed information on the suppression mechanism. The production of Lambda and K0s at mid-rapidity in pp and Pb-Pb at sqrt(sNN) = 2.76 TeV is studied with the ALICE detector at the LHC. Lambda...
Prof.
Thomas Humanic
(Relativistic Heavy Ion Group, Department of Physics - Ohio State U.)
5/23/11, 6:10 PM
Identical neutral kaon pair correlations are measured in 7 TeV proton+proton collisions in the ALICE experiment. Neutral kaons are identified from their decay into π+π- pairs. K0sK0s correlation functions are formed in 4 multiplicity x 4 kT bins. The kaon source parameters Rinv and λ are extracted from these correlation functions by fitting a Gaussian*PYTHIA model to them, the Gaussian...
Prof.
Rainer Fries
(Texas A&M University + RBRC)
5/23/11, 6:10 PM
We review resonance recombination for quarks and show that it is compatible with quark and hadron distributions in local thermal equilbrium. We then calculate realistic heavy quark phase space distributions in heavy ion collisions using Langevin simulations with non-perturbative interactions in hydrodynamic backgrounds. We hadronize the heavy quarks on the critical hypersurface given by...
Dr
Silvia Masciocchi
(GSI Darmstadt)
5/23/11, 6:30 PM
Heavy quarks (charm and beauty) are among the most important probes that allow to test perturbative QCD descriptions of hard processes in hadronic interactions, as well as to study the hot matter produced in high energy nucleus-nucleus collisions. Precision measurements of heavy flavour production in proton-proton collisions provide the necessary reference for the interpretation of their...
Prof.
Yuriy Sinyukov
(Bogolyubov Institute for Theoretical Physics)
5/23/11, 6:30 PM
A study of energy behavior of the pion spectra and interferometry radii is carried out for the SPS, RHIC and LHC energies within the hydrokinetic approach. The main mechanisms that lead to the paradoxical, at first sight, dependence of the femtoscopy scales on a collision energy, in particular, a decrease of Rout/Rside ratio with the energy growth, are exposed. The hydrokinetic predictions for...
Prof.
Roy Lacey
(Stony Brook University)
5/23/11, 6:30 PM
The higher-order flow harmonics $v_n$ can provide constraints crucial for precision extraction of the specific shear viscosity eta/s, of the plasma (QGP) produced in full energy ($\sqrt{s_{NN}}=200$ GeV) Au+Au collisions at RHIC. It can also provide reliable estimates of the flow correlations which contribute to the underlying event for jet-driven two-particle azimuthal angle correlation...
Dr
Anton Andronic
(Gesellschaft fuer Schwerionenforschung mbH (GSI))
5/23/11, 6:30 PM
In our model, both the light (u,d,s) quark sector and charm(onium)
have found a unified description, thus providing very different
probes for a possible delineation of the phase boundary between
deconfined and hadronic matter produced in nucleus-nucleus collisions
from low (AGS) energies up to RHIC energy.
A purely thermal production (at chemical freeze-out) appears natural
for...
Dr
Claudia Ratti
(Torino University)
5/23/11, 6:50 PM
We present the new results of the Wuppertal-Budapest lattice QCD collaboration on flavor diagonal and non-diagonal quark number susceptibilities with 2+1 staggered quark flavors, in a temperature regime between 120 and 500 MeV. A Symanzik improved gauge and a stout-link improved staggered fermion action is utilized; the light and strange quark masses are set to their physical values. Lattices...
Dr
Alexander Schmah
(Lawrence Berkeley National Lab)
5/23/11, 6:50 PM
The main goal of the RHIC Beam Energy Scan (BES) is the exploration
of the QCD phase diagram in the region of a possible phase
transition between the Quark Gluon Plasma (QGP) and the hadron gas
phase. In the year 2010 the first part of the BES program was
successfully accomplished by recording data from Au+Au collisions
at $\sqrt{s_{NN}}=$ 7.7, 11.5 and 39 GeV. The second harmonic...
Dr
Heng-Tong Ding
(Brookhaven National Lab)
5/23/11, 6:50 PM
We analyze the low energy part of charmonium spectral functions on large lattices close to the continuum limit in the temperature region $1.5<T/T_c<3$ as well as for $T \simeq 0.75T_c$. We present evidence for the existence of a transport peak above $T_c$ and its absence below $T_c$. The heavy quark diffusion constant is then estimated using the Kubo formula. As part of the calculation we also...
Dr
Deepali Sharma
(Weizmann Institute of Science)
5/23/11, 6:50 PM
The PHENIX experiment at RHIC has carried out systematic measurements of $\phi$ and $\omega$ mesons in $p+p$, $d+Au$, $Cu+Cu$ and $Au+Au$ collisions at $\sqrt{s_{NN}}$ = 200 GeV. Consistent results have been obtained using leptonic and hadronic decay modes as well as different analysis techniques.
In $p+p$ collisions, the transverse momentum distributions of $\omega$ and $\phi$, as well...
Zhen Hu
(Purdue University)
5/23/11, 7:10 PM
The LHC centre-of-mass energy allows copious $\Upsilon$ production in PbPb collisions. Detailed measurements of bottomonium will help characterize the dense matter produced in heavy-ion collisions beyond what was accessible at RHIC (mostly) with charmonia. The full spectroscopy of quarkonium states has been suggested as a possible thermometer for the QGP. With its excellent dimuon mass...
Prof.
Joseph Kapusta
(University of Minnesota)
5/23/11, 7:10 PM
Hydrodynamic fluctuations have been applied to a wide variety of physical, chemical, and biological phenomena in the past decade. In the context of high energy heavy ion collisions, there will be intrinsic fluctuations due to the finite size and finite particle content even if the initial conditions are fixed. We develop the theory of relativistic fluctuations, and apply it to a 1+1...
Dr
Harri Niemi
(Frankfurt Institute for Advanced Studies)
5/23/11, 7:10 PM
We investigate the effects of a temperature-dependent shear
viscosity-to-entropy density ratio $\eta/s$ on the elliptic
flow of hadrons in ultrarelativistic heavy-ion collisions [1].
We use relativistic dissipative fluid dynamics to model the
space-time evolution of the hot and dense system formed in
such collisions. The final hadron spectra are calculated using
the Cooper-Frye...
Alessandro De Falco
(Univ. + INFN Cagliari)
5/23/11, 7:10 PM
Low mass meson ($\rho^0, \omega, \phi$) production provides key information on the hot and dense state of strongly interacting matter produced in high-energy heavy ion collisions. Among them, strangeness enhancement can be accessed through the measurement of $\phi$ meson production, while the measurement of the $\rho$ spectral function can be used to reveal in-medium modifications of hadron...
Javier Lopez Albacete
(IPhT CEA/Saclay)
5/24/11, 8:30 AM
Pre-equilibrium and initial state physics
Plenary
Dr
Alberica Toia
(Organisation européenne pour la recherche nucléaire (CERN))
5/24/11, 8:55 AM
Pre-equilibrium and initial state physics
Plenary
Global variables, such as the charged particle multiplicity and the transverse energy are important observables to characterize Relativistic Heavy Ion collisions and to constrain model calculations. The charged-particle multiplicity dNch/deta(eta=0) and transverse energy dEt/deta(eta=0) are measured at sqrt(s_NN)=2.76TeV in Pb-Pb collisions as a function of centrality and in p-p collisions....
Bernd Mueller
(Duke University)
5/24/11, 9:35 AM
Global and collective dynamics
Plenary
Björn Schenke
(Brookhaven National Laboratory)
5/24/11, 10:20 AM
Plenary
Shinichi Esumi
(Institute of Physics - University of Tsukuba)
5/24/11, 10:45 AM
Recent collective flow measurements including higher moment
event anisotropy from the PHENIX experiment will be presented,
the particle type, beam energy dependence and the relation with
jet modification will be discussed.
Julia Velkovska
(Vanderbilt University)
5/24/11, 11:05 AM
We report on the CMS measurements of charged hadron anisotropic azimuthal
distributions from PbPb collisions at √sNN= 2.76 TeV and their
decomposition into a Fourier series up to the 6th coefficient. The results are
presented as a function of transverse momentum, centrality and pseudorapidity
and cover a broad kinematic range. The relation between the different harmonic
coefficients and...
Jiangyong Jia
(Brookhaven National Laboratory (BNL)- Stony Brook University)
5/24/11, 11:25 AM
Raimond Snellings
(Nikhef, Amsterdam,The Netherlands)
5/24/11, 11:45 AM
We report on the measurements of anisotropic flow with the ALICE detector at the LHC. For charged particles we present the first triangular, quadrangular and pentagonal flow measurements. The flow of charged and identified particles is compared to hydrodynamic model predictions at low-p_t and for identified particles at intermediate-p_t the so-called number of constituent quark scaling is...
Ulrich Heinz
(Ohio State University)
5/24/11, 12:10 PM
Torsten Dahms
(LLR - Ecole Polytechnique, IN2P3-CNRS)
5/24/11, 3:00 PM
CMS is fully equipped to measure hard probes in the di-muon decay channel in the high multiplicity environment of nucleus-nucleus collisions. Such probes are especially relevant for studying the quark gluon plasma since they are produced at early times and propagate through the medium, mapping its evolution. In particular, the $J\psi$ production in heavy ion collisions has been studied at...
Frithjof Karsch
(Brookhaven National Laboratory)
5/24/11, 3:00 PM
In the chiral limit and at temperatures close to the QCD phase transition temperature physical observables are expected to show universal properties that are controlled by the symmetry class of a 3-dimensional O(4) spin model [1]. Higher moments of net baryon number as well as electric charge fluctuations are sensitive to these universal features of the chiral phase transition [2].
The...
Marguerite Belt Tonjes
(University of Maryland)
5/24/11, 3:00 PM
Jets are an important tool to probe the hot, dense medium that is produced in ultra-relativistic heavy ion collisions. The large collision energy at the LHC provides copious production of dijets with energies that can be cleanly identified above the heavy ion background. The multipurpose Compact Muon Solenoid (CMS) detector is well designed to measure these hard scattering processes with its...
Dr
Andrew Adare
(Yale University)
5/24/11, 3:00 PM
Angular correlations between unidentified hadron trigger and
associated particles are measured by the ALICE experiment for $0.5 <
p_{t}^{(t),(a)} < 15$ GeV/c, where $p_t^{(t)} > p_t^{(a)}$. The
modification of conditional yields in central Pb--Pb collisions is
measured with respect to p--p ($I_{AA}$) and with respect to peripheral
events ($I_{CP}$). Significant suppression is observed on...
Jeremy Louis Callner
(Physics Department-University of Illinois at Chicago)
5/24/11, 3:20 PM
Measurements of charged dihadron correlations from the CMS collaboration are presented for PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair over a broad range of pseudorapidity and the full range of azimuthal angle. With its large pseudorapidity coverage (|$\eta$|<2.4), the CMS tracker is ideally suited for detailed analyses of both short and long-range charged hadron...
Dr
Roberta Arnaldi
(INFN Torino)
5/24/11, 3:20 PM
The ALICE experiment has studied J/psi production at forward rapidity from pT=0, through its dimuon decay channel, in proton-proton and Pb-Pb collisions at the LHC.
Results obtained in proton-proton collisions at sqrt(s)=7 TeV will be discussed. The integrated and differential (in pT and rapidity) inclusive production cross sections will be presented and compared to results from other LHC...
Aaron Richard Angerami
(Columbia University)
5/24/11, 3:20 PM
Jet quenching, the parton energy loss in the hot and dense medium created in ultra-relativistic heavy ion collisions, is a well-established experimental phenomenon at RHIC. However, existing single hadron, di-hadron and multi-hadron measurements from RHIC do not provide a complete understanding of the experimental results and do not sufficiently constrain theoretical models. Reconstructed jet...
Zebo Tang
(University of Science and Technology of China)
5/24/11, 3:40 PM
The $c\bar{c}$ bound state $J/\psi$ provides a unique tool to probe the properties of the hot dense medium produced in heavy-ion collisions, but to date its production mechanism is not understood clearly either in heavy-ion collisions or in hadron hadron collisions. Measurement of $J/\psi$ production at high $p_T$ is particularly interesting since at high $p_T$ the various models give...
Dr
José Guilherme Milhano
(Instituto Superior Tecnico (IST) and CERN PH-TH)
5/24/11, 3:40 PM
The ATLAS and CMS Collaborations recently reported strong modifications of dijet properties in heavy ion collisions. In this work, we discuss the extent to which these first data constrain the microscopic mechanism underlying jet quenching. Simple kinematic arguments lead us to identify a frequency collimation mechanism via which the medium efficiently trims away the soft components of the jet...
Dr
Anthony Timmins
(University of Houston)
5/24/11, 3:40 PM
We present measurements of untriggered di-hadron correlations as a function of centrality in Pb-Pb \sqrt{s_{NN}} =2.76 TeV collisions, for charged hadrons with p_{T} > 0.15 GeV/c. These measurements provide a map of the bulk correlation structures in heavy-ion collisions. Contributions to these structures may come from jets, initial density fluctuations, elliptic flow, and/or momentum...
Yaxian Mao
(CCNU, Wuhan & LPSC, Grenoble)
5/24/11, 4:00 PM
Two-particle correlation with the high-pT triggers allows the study of the hard scattering phenomena like soft QCD radiation [1, 2], angular ordering [3] or jet frag- mentation in the low and intermediate pT region [4, 5] where full jet reconstruction is challenging. An analysis of the first ALICE pp data where charged particle, π0 and isolated photon are used as trigger particles will be...
Dr
Vladimir Skokov
(GSI, Darmstadt, Germany)
5/24/11, 4:00 PM
Fluctuations of conserved charges are key probes of the chiral
phase transition in a QCD medium. Of particular phenomenological importance are studies of such fluctuations at finite baryon density. A valuable tool for assessing critical fluctuations and the thermodynamics at non-vanishing baryon density is provided by effective chiral models.
We consider the Polyakov loop-extended two...
Abhisek Sen
(Georgia State University)
5/24/11, 4:00 PM
Quarkonia suppression is one of the highly cited
signature of quark gluon plasma (QGP) formed in relativistic heavy
ion collisions. PHENIX observed a high suppression of $J/\Psi$
production in Au+Au collisions at $\sqrt{s}=200$ GeV. However,
theoretical predictions remain diverse due to lack of precise
knowledge of heavy flavor meson production, suppression,
regeneration in hot and dense...
Dr
Ivan Vitev
(Los Alamos National Laboratory)
5/24/11, 4:00 PM
Jets physics is an important new area of active research at RHIC and at the LHC that paves the way for novel tests of QCD multi-parton dynamics in heavy-ion reactions. At present, perturbative QCD calculations of hard probes in “elementary” nucleon-nucleon reactions can be consistently combined with the effects of the nuclear medium up to next-to-leading order. While such accuracy is desirable...
Prof.
Chiho Nonaka
(Nagoya University)
5/24/11, 4:20 PM
From phenomenological considerations, J/psi suppression was proposed
as a signature of QGP production in relativistic heavy ion collisions,
and has been considered as one of the most promising ones [1].
However recent lattice QCD calculations show that charmonia survive even above the
critical temperature [2], which presents the possibility that the scenario of J/psi
suppression in...
Stefan Heckel
(Johann-Wolfgang-Goethe Univ.)
5/24/11, 4:20 PM
Non-statistical event-by-event fluctuations of the mean transverse momentum of charged particles in pp and Pb--Pb collisions are studied using the ALICE experiment at the LHC. The analysis is performed at $|\eta| < 0.8$ and $0.15 < p_{T} < 2 $~GeV/c. Multiplicity dependent results are obtained for pp collisions at $\sqrt{s}$~=~0.9, 2.76 and 7~TeV. Pb--Pb collisions at...
Dr
Christian Klein-Boesing
(IKP Muenster)
5/24/11, 4:20 PM
The quantification of the effect of parton energy loss, known as jet
quenching, is one of the major goals of jet and high $p_T$
measurements in heavy-ion collisions. Here, the aim of the reconstruction of
jets, as compared to single particle measurements, is to provide a more direct
access to the original parton properties and the modification of the
fragmentation process in heavy-ion...
Dr
Pasi Huovinen
(Johann Wolfgang Goethe-Universität)
5/24/11, 4:20 PM
The effects of non-zero baryon density are expected to become important
in hydrodynamic modeling of heavy collisions below the highest energy at RHIC. Recent calculations in effective models and in QCD using Dyson Schwinger equation suggest that the transition in QCD remains a crossover up to baryon chemical potentials of about 800MeV [1]. If so, the equation of state relevant for...
Thorsten Renk
(University of Jyväskylä)
5/24/11, 4:40 PM
Despite a wealth of experimental data for high p_T processes in heavy-ion collisions, discriminating between different models of hard parton-medium interactions has been difficult. A large reason is that the pQCD parton spectrum at RHIC is so steeply falling that distinguishing even a moderate shift in parton energy from complete parton absorption is essentially impossible. In essence, energy...
Tim Schuster
(Frankfurt Institute for Advanced Studies, Goethe-University Frankfurt)
5/24/11, 4:40 PM
Event-by-event fluctuations of hadron ratios characterize the hadro-chemical composition of the hot and dense medium created in heavy-ion collisions. This makes the fluctuation signal sensitive to changes in the underlying structure of matter, and phase transition effects in particular. In the SPS energy range, inclusive hadronic observables indicate the onset of the deconfinement phase...
Dr
Jean-Philippe Lansberg
(IPNO, Université Paris-Sud 11)
5/24/11, 4:40 PM
I will discuss the impact of QCD corrections on the P_T differential cross section for quarkonium production in pp collisions at RHIC, Tevatron and LHC energies, as well as the contributions from charm-gluon fusion. I will present comparisons between the predictions of the Color Singlet Model up to alpha_s^5 with the first LHC data both for J/psi and Upsilon. I will also show predictions for...
Prof.
Sourendu Gupta
(TIFR, Mumbai)
5/24/11, 4:40 PM
We present a test of QCD in the non-perturbative domain through a comparison of thermodynamic fluctuations predicted in lattice computations with the experimental data of baryon distributions in high-energy heavy-ion collisions. This study provides evidence for thermalization in these collisions, and allow us to set a scale for the QCD phase diagram. The scale is the temperature for the cross...
Prof.
Sergei Voloshin
(Department of Physics and Astronomy-College of Science-Wayne Sta)
5/24/11, 5:00 PM
The system created in a heavy ion collision in general is not azimuthally symmetri; moreover, the initial spatial distribution, e.g. that of the energy density, fluctuates event-by-event even at fixed impact parameter. Because of particle interactions, this initial spatial asymmetry leads to anisotropies in particle emission -- the phenomenon called anisotropic flow. The best known anisotropy...
Dr
Philippe Pillot
(SUBATECH, Nantes)
5/24/11, 5:00 PM
Heavy quarkonium states are expected to provide essential information on the properties of the high-density strongly-interacting system formed in the early stages of high-energy heavy-ion collisions. Such probes are especially promising at LHC energies, where heavy quarks are copiously produced.
ALICE is the experiment at the LHC mainly dedicated to the study of nucleus-nucleus collisions....
Dr
Nathan Grau
(Augustana College)
5/24/11, 5:00 PM
Fully reconstructed jets and hadrons correlated with a direct photon significantly reduce energy-loss bias, the bias toward measuring particles from partons which suffer little energy loss. In d+Au collisions, one accesses the physics at large $x$, which yields important constraints for nuclear parton distribution functions. In both d+Au and A+A collisions, coherent multiple-scattering models...
Dr
Nan Su
(Bielefeld University)
5/24/11, 5:00 PM
The weak-coupling expansion of the QCD free energy is known to order g^6*log[g], however, the resulting series is poorly convergent at phenomenologically relevant temperatures. I will discuss how the gauge invariant hard-thermal-loop perturbation theory (HTLpt) reorganization of the calculation improves the convergence of the successive approximations to the QCD free energy. I will present new...
Harald Appelshaeuser
(Johann-Wolfgang-Goethe Univ.)
5/25/11, 8:30 AM
We present transverse momentum distributions of charged particles and identified hadrons in pp and Pb-Pb collisions, measured by ALICE at the LHC. The Pb-Pb data are presented in intervals of the collision centrality and cover transverse momenta up to 50 GeV/c. Nuclear medium effects are studied in terms of the nuclear modification factor R_AA. The results indicate strong suppression of...
Yen-Jie Lee
(Massachusetts Inst. of Technology (MIT))
5/25/11, 8:55 AM
We report the measurement of transverse momentum spectra of the charged hadrons and photons in √sNN = 2.76 TeV PbPb collisions with the CMS detector. The nuclear modification factors are constructed by dividing the PbPb pT spectra,
normalized to the number of binary collisions, by the pp references.
Dr
Martin Purschke
(BROOKHAVEN NATIONAL LABORATORY)
5/25/11, 9:20 AM
Francois Arleo
(lapp-Laboratoire d'Annecy-le-Vieux de Physique des Particules-In)
5/25/11, 9:35 AM
I will discuss the generic features of parton energy loss effects on the quenching of large-pT hadrons, as well as more quantitative studies. The differences expected from RHIC to LHC will be highlighted. The quenching of prompt photons will also be discussed in detail. Finally, I will stress the need for precise baseline measurements of hadrons and photons in pp and pPb collisions.
Miklos Gyulassy
(Columbia University)
5/25/11, 10:00 AM
Korinna Zapp
(University of Heidelberg)
5/25/11, 10:50 AM
Helen Louise Caines
(Yale University-Unknown-Unknown)
5/25/11, 11:15 AM
Dr
Christof Roland
(Massachusetts Institute of Technology)
5/25/11, 11:35 AM
The energy loss of fast partons traversing the strongly interacting matter
produced in high-energy nuclear collisions is one of the most interesting
observables to probe the nature of the produced medium. The multipurpose
Compact Muon Solenoid (CMS) detector is well designed to measure these hard
scattering processes with its high resolution calorimeters and high precision
silicon...
Brian Cole
(Physics Dept., Pupin Physics Lab.-Columbia University-Unknown)
5/25/11, 12:00 PM
Peter Jacobs
(Lawrence Berkeley National Laboratory)
5/25/11, 12:25 PM
Dima Kharzeev
(Unknown),
John Harris
(Yale),
Thomas Ullrich
(Brookhaven National Laboratory)
5/25/11, 3:20 PM
Prof.
Hideki Hamagaki
(Graduate School of Science-University of Tokyo),
Kenta Shigaki
(Hiroshima University)
5/25/11, 3:40 PM
Peter Braun-Munzinger
(Gesellschaft fuer Schwerionenforschung mbH (GSI))
5/25/11, 4:00 PM
Luisa Cifarelli-Strolin
(Dipartimento di Fisica)
5/25/11, 4:20 PM
Swagato Mukherjee
(Brookhaven National Laboratory)
5/26/11, 8:30 AM
Bedangadas Mohanty
(Variable Energy Cyclotron Centre, Kolkata)
5/26/11, 8:55 AM
Plenary
Marek Gazdzicki
(Frankfurt University)
5/26/11, 9:20 AM
Plenary
Prof.
Krzysztof Redlich
(University of Wroclaw, Institute of Theoretical Physics)
5/26/11, 10:00 AM
Plenary
Matthew Luzum
(IPhT CEA/Saclay)
5/26/11, 10:50 AM
Plenary
Jan Fiete Grosse-Oetringhaus
(CERN)
5/26/11, 11:40 AM
The talk presents results from hadron correlations in PbPb collisions at 2.76 TeV with ALICE. Untriggered di-hadron correlations studies are shown which provide a map of the bulk correlation structures in heavy-ion collisions. The long-range correlation region is further studied by triggered correlations which addresses the dependence on trigger and associated pT. The measured correlation...
Paul Sorensen
(BNL)
5/26/11, 12:00 PM
Plenary
Volker Koch
(Lawrence Berkeley National Laboratory)
5/26/11, 12:15 PM
Plenary
Jacek Otwinowski
(Research Division and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany)
5/26/11, 3:00 PM
The observed suppression of high-pT particle production in heavy-ion collisions is generally attributed to energy loss of partons as they propagate through the hot and dense QCD medium. Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at sqrt(s)=2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented in intervals of...
Thomas Ullrich
(Brookhaven National Laboratory)
5/26/11, 3:00 PM
Experiments upgrade, future facilities and instrumentations
Parallel
The probing of nuclei and nucleons via deep-inelastic and diffractive processes in the high-energy (low-x) regime will open a new precision window for the investigation of the gluonic structure of matter.
Studies of e+p collisions at HERA and especially d+Au collisions at RHIC have found tantalizing hints of saturated gluon densities, a phenomenon with substantial impact on the physics of...
Dr
Marcus Bluhm
(Laboratoire SUBATECH)
5/26/11, 3:00 PM
The strong quenching of jets and the suppression of hadron spectra
at high transverse momenta are striking experimental observations
made in high energy nuclear collisions. Both have been interpreted
as signature for the formation of a deconfined plasma of QCD
matter, in which partons suffer a medium-induced energy loss. In
theoretical studies devoted to a parton's radiative energy...
Jorge A Robles
(University of California (UCD))
5/26/11, 3:00 PM
The unprecedented centre-of-mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions at extreme temperatures and very low parton momentum fractions. With its high precision, large acceptance for tracking and calorimetry, and a trigger scheme that allows the analysis of almost each minimum bias...
Nestor Armesto Perez
(Universidade de Santiago de Compostela)
5/26/11, 3:20 PM
Experiments upgrade, future facilities and instrumentations
Parallel
I will show the possibilities for electron-ion studies offered by the proposed electron-hadron collider at CERN, the Large Hadron-electron Collider [1]. After a short introduction on open problems at small x, I will briefly present the machine and detector. Then I will focus on small-x aspects in electron-nucleus collisions, first on inclusive measurements and the determination of nuclear...
Dr
Rikard Sandström
(Max Planck Institut)
5/26/11, 3:20 PM
A broad program of measurements using heavy ion collisions is underway in ATLAS, with the aim of studying the properties of QCD matter at high temperatures and densities. Leptonic observables are essential tools for the study of heavy ion collisions since leptons do not interact strongly and thus pass through the strongly-coupled medium unaffected. The centrality dependence of J/psi and Z...
Alexander Milov
(Weizmann Institute of Science)
5/26/11, 3:20 PM
The measurement of charged particle spectra in heavy ion collisions is a direct way to study properties of hot and dense matter created in these interactions. The centrality dependence of the spectral shape is an important tool to understand the interplay between collective flow and energy loss mechanisms. The ATLAS detector at the LHC took lead-lead data at 2.76 TeV per nucleon-nucleon pair...
Dr
Raju Venugopalan
(Brookhaven National Laboratory)
5/26/11, 3:20 PM
We discuss an ab initio computation of the initial spectrum of fluctuations in the pre-equilibrium Glasma formed in heavy ion collisions [1]. Our result resums to all loop orders the leading unstable quantum fluctuations at early times. We showed explicitly previously for a scalar field theory [2] that averaging over the analogous spectrum of initial fluctuations leads to hydrodynamic...
Dr
Mickey Chiu
(Brookhaven National Lab)
5/26/11, 3:40 PM
RHIC experiments have observed that inclusive hadron yields in
the forward rapidity (deuteron) direction for $\sqrt{s_{NN}} = 200$
GeV d+Au collisions are suppressed relative to p+p collisions.
The mechanism for the suppression has not been firmly established;
theoretical descriptions include nuclear shadowing, initial-state parton energy loss, and gluon saturation. We present...
Prof.
Alexander Sorin
(Joint Institute for Nuclear Research)
5/26/11, 3:40 PM
Experiments upgrade, future facilities and instrumentations
Parallel
New project NICA/MPD (Nuclotron-based Ion Collider fAcility/MultiPurpose Detector) is now under realization phase at JINR (Dubna). The main goal of the project is to start in the coming years an experimental study of hot and dense strongly interacting matter and search for possible signs of the mixed phase and critical endpoint in heavy ion collisions. This study should be carried out at...
William Horowitz
(University of Cape Town)
5/26/11, 3:40 PM
We present parameter-free predictions from the WHDG (radiative+elastic+geometric fluctuation) energy loss model for high pT pion suppression in A+A at 2.76 and 5.5 ATeV. The input density is constrained from a rigorous statistical analysis of RHIC pi0 quenching data. The predictions are consistent with the recent _charged_ hadron RAA data from ALICE only within the current very large...
Prof.
Thomas Peitzmann
(Universiteit Utrecht)
5/26/11, 4:00 PM
Experiments upgrade, future facilities and instrumentations
Parallel
The ALICE experiment is specifically designed for the study of strongly interacting matter as created in heavy ion collisions at LHC. With some of its particular features, like the very good measurement of low momentum particles and the particle identification capabilities it also provides unique measurements in p+p collisions. However, very recent developments in heavy ion physics suggest...
Hannah Petersen
(Duke University)
5/26/11, 4:00 PM
This talk will discuss how triangular flow measurements in Pb+Pb collisions at
the LHC can be used to constrain the origin of initial state fluctuations. We
explore the energy dependence of elliptic and triangular flow within a
(3+1)-dimensional hybrid framework starting from a non-equilibrium initial state
with event-by-event fluctuations and including an ideal hydrodynamical...
Mihael Makek
(Weizmann Institute of Science)
5/26/11, 4:00 PM
Dileptons are valuable probes in the investigation of the hot and
dense matter formed in heavy ion collisions, since they interact only electromagnetically and thus their path from the interaction region to the detectors is almost undisturbed. They can provide information about the matter properties in the early stages of the collisions where deconfinement and chiral symmetry restoration are...
Prof.
Hanzhong Zhang
(IOPP)
5/26/11, 4:00 PM
Nuclear modification factor $R_{AA}(p_{T})$ for large transverse momentum pion spectra in $Pb+Pb$ collisions at $\sqrt{s}=2.76$ TeV is predicted within the NLO perturbative QCD parton model. Effect of jet quenching is incorporated through medium modified fragmentation functions within the higher-twist approach. The jet transport parameter that controls medium modification is proportional to...
Andre Yoon
(Massachusetts Inst. of Technology (MIT))
5/26/11, 4:20 PM
The nuclear modification factor R_AA is one of the key signatures for the energy loss of fast partons traversing a QCD medium. Charged particle transverse momentum (pT) spectra have been measured by CMS for pp collisions at sqrt(s)=0.9 and 7 TeV, corresponding to integrated luminosities of 231 ub-1 and 2.96 pb-1, respectively. Calorimeter-based high-transverse-energy jet triggers are employed...
Rupa Chatterjee
(University of Jyvaskyla)
5/26/11, 4:20 PM
Thermal photon emission is widely believed to reflect properties of the earliest, hottest evolution stage of the medium created in ultra-relativistic heavy-ion collisions. Previous computations of photon emission have been carried out using a hydrodynamical medium description with smooth, averaged initial conditions. Recently, more sophisticated hydrodynamical models which calculate...
Frederique Grassi
(Instituto de Fisica-Universidade de Sao Paulo)
5/26/11, 4:20 PM
Relativistic nuclear collisions data on two-particle correlations exhibit structures as function of relative azimuthal angle and rapidity. A unified description of these near-side and awayside structures is proposed for low to moderate transverse momentum. It is based on the combined effect of tubular initial conditions and hydrodynamical expansion.
A 3+1 hydrodynamic approach with...
Anne Sickles
(Brookhaven)
5/26/11, 4:20 PM
Experiments upgrade, future facilities and instrumentations
Parallel
The first decade of RHIC physics and the first heavy ion running at the LHC have produced a wealth of data and discoveries. It is timely to now evaluate what has been learned and ask what compelling new questions have been raised. In this talk, several key unanswered questions about the properties of the strongly coupled quark gluon plasma and the distribution of partons inside nucleons and...
Dr
Paloma Quiroga Arias
(LPTHE , UPMC Univ. Paris 6)
5/26/11, 4:40 PM
Recent developments in the computation of the NLO improvement for non-linear QCD evolution equations has allowed, for the first time, for the consistent description of experimental data using a first principle approach. In particular, the Balitsky-Kovchegov equation including running coupling effects (rcBK) has been shown to provide an excellent global description of inclusive DIS data.
I...
Dr
Edouard Kistenev
(Brookhaven National Laboratory)
5/26/11, 4:40 PM
E.Kistenev for the PHENIX Collaboration
Direct photon production in heavy ion collisions in PHENIX experiment at RHIC
Among the observables used to probe the high temperature and high density phase of heavy nucleus collisions direct photons are considered of particular interest. At LO direct photons are produced in quark-gluon Compton scattering and quark-antiquark annihilation, the...
Prof.
Carl Gagliardi
(STAR Collaboration)
5/26/11, 4:40 PM
Experiments upgrade, future facilities and instrumentations
Parallel
The STAR Collaboration has identified eight key questions that will drive RHIC science during the coming decade, six of which involve ultrarelativistic heavy-ion collisions. What is the nature of the initial state in nuclear collisions? What are the properties of the strongly-coupled system produced at RHIC, and how does it thermalize? Are the interactions of energetic partons with QCD...
Dr
Gustavo Conesa Balbastre
(LPSC - Grenoble)
5/26/11, 4:40 PM
The ALICE experiment at the LHC has measured the transverse momentum spectra of neutral mesons via the two photon decay in pp and Pb-Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV over a wide transverse momentum range with different subsystems: with the electromagnetic calorimeters PHOS and EMCAL and via conversions of the photons in the inner material of the experiment to e+e--pairs reconstructed...
Dr
Ken Oyama
(University of Heidelberg)
5/26/11, 5:00 PM
Experiments upgrade, future facilities and instrumentations
Parallel
Measurements of reference trigger cross sections were obtained with the ALICE detector, based on beam properties measured from van der Meer scans where convolution of the beam profiles were evaluated. The measurement is essential for absolute cross section determination of the physics processes.
Based on this measurement, inelastic cross sections characterizing proton-proton collisions at...
Dr
Andrea Beraudo
(Centro Studi e ricerche "Enrico Fermi" - Rome (Italy))
5/26/11, 5:00 PM
Heavy ion collisions at both RHIC and the LHC show strong medium-induced modifications of high-pT single inclusive hadron spectra, jet-like particle correlations and reconstructed jets.
A dynamical understanding of these jet quenching phenomena is typically sought within a partonic picture in which the energy of highly energetic parent partons is degraded due to
multiple inelastic and/or...
Prof.
Hirotsugu Fujii
(University of Tokyo)
5/26/11, 5:00 PM
A color glass condensate (CGC) model for particle productions at collider energies is confronted with the data at RHIC and LHC. When applying the CGC picture to high-energy scatterings at LHC (or higher) energies, we need to include the effects of the running coupling and the transverse expansion of the colliding hadrons. These two are appropriately incorporated here. Main features of our...
Prof.
Charles Gale
(McGill University)
5/26/11, 5:00 PM
We investigate the yield and the azimuthal anisotropy of produced photons in heavy-ion collisions at RHIC and at LHC energies. We study the photons produced from a variety of sources, including those from primordial nucleon-nucleon collisions, from thermal partons, from fragmenting QCD jets, from jets interacting with thermal partons, and from thermal hadrons. We study the interplay of those...
David Mateos
(ICREA & U. Barcelona)
5/27/11, 8:30 AM
Cesar luiz daSilva
(Los Alamos National Lab)
5/27/11, 9:00 AM
Andrea Dainese
(INFN Padova)
5/27/11, 9:25 AM
The ALICE experiment studies nucleus–nucleus collisions at the LHC in order to investigate the properties of QCD matter at extreme energy densities. The measurement of open charm and open beauty production allows to investigate the mechanisms of heavy-quark propagation, energy loss and hadronization in the hot and dense medium formed in high-energy nucleus-nucleus collisions. In particular,...
Dima Kharzeev
(Brookhaven National Laboratory)
5/27/11, 9:50 AM
Catherine Silvestre
(Los Alamos National Laboratory (LANL)-Laboratoire de Physique Subatomique et Cosmologie (LPSC, Grenoble))
5/27/11, 10:30 AM
CMS is fully equipped to measure hard probes in the di-muon decay channel in the high multiplicity environment of nucleus-nucleus collisions. Such probes are
especially relevant for studying the quark gluon plasma since they are produced
at early times and propagate through the medium, mapping its evolution.
Quarkonia and bottomonia are sensitive to the evolution of the medium....
Gines Martinez-Garcia
(Laboratoire de Physique Subatomique et des Technologies Associees)
5/27/11, 10:55 AM
ALICE detector has excellent performances to study quarkonium production in
heavy-ion collisions at the LHC collider [1]. In this new energy regime, charmonium could reveal a privileged probe to study the properties of the high-density strongly interacting system formed in the early stages of high-energy heavy-ion collisions [2].
Bottomonium resonances will be abundantly produced, providing...
Dmitri Kharzeev
(Stony Brook U./BNL)
5/27/11, 11:10 AM
Yvonne Chiara Pachmayer
(Ruprecht-Karls-Universitaet Heidelberg)
5/27/11, 11:30 AM
Tzvetalina Stavreva
(LPSC)
5/27/11, 11:40 AM
Elvira Santini
(Frankfurt University)
5/27/11, 11:50 AM
Hui Wang
(Michigan state university)
5/27/11, 12:00 PM
Natasha Sharma
(Department of Physics-Panjab University)
5/27/11, 12:10 PM
Wolfgang Unger
(ETH Zuerich)
5/27/11, 12:20 PM
Mihee Jo
(Korea University (KR))
5/27/11, 12:30 PM
Dr
Andrea Rossi
(Sezione di Padova (INFN)-Universita e INFN)
5/27/11, 3:00 PM
The comparison of heavy flavour production in proton-proton and heavy-ion collisions allows to probe the properties of the high-density QCD medium formed in the latter and to study the mechanism of in-medium partonic energy loss. The ALICE experiment has measured the D meson production in pp and Pb--Pb collisions at the LHC at $\sqrt{s}=7$ and $2.76~{\rm TeV}$ and $\sqrt{s_{NN}} = 2.76~{\rm...
Adam Trzupek
(Henryk Niewodniczanski Inst. Nucl. Physics, PAN)
5/27/11, 3:00 PM
The measurement of the elliptic flow for charged particles in Pb+Pb collisions at sqrt(s_NN)=2.76 TeV with the ATLAS detector will be presented in a wide range of pseudorapidity, transverse momentum and collision centrality. The elliptic flow is measured by correlating azimuthal angles of reconstructed particle tracks with the event plane angle obtained from forward calorimeters. A large...
Peter Arnold
(University of Virginia)
5/27/11, 3:00 PM
A very basic theoretical question is: How far does a high-energy excitation travel in a quark-gluon plasma, and how does that distance scale with energy? In weak coupling, the stopping distance scales with energy as E^(1/2), up to logarithms. In strongly-coupled plasmas with gravity duals, theorists have found that the maximum stopping distance scales instead like E^(1/3). In the latter...
Hannu Holopainen
(University of Jyväskylä)
5/27/11, 3:20 PM
We develop a framework for event-by-event ideal hydrodynamics to study the differential elliptic flow which is measured at different centralities in Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). Fluctuating initial energy density profiles, which here are the event-by-event analogues of the eWN profiles, are created using a Monte Carlo Glauber model. Using the same event plane...
Oliver Fochler
(Institut für Theoretische Physik, Goethe-Universität Frankfurt)
5/27/11, 3:20 PM
We present fully dynamic simulations of heavy ion collisions at RHIC and at LHC energies within the perturbative QCD-based partonic transport model BAMPS (Boltzmann Approach to Multi-Parton Scatterings). We focus on the simultaneous investigation of high-pT observables, such as jet quenching, and bulk observables, such as the elliptic flow. The model features inelastic 2 <-> 3 processes based...
Mr
Hao Ma
(Universidad de Santiago de Compostela)
5/27/11, 3:20 PM
Medium modifications of jets have previously been thoroughly studied by calculating the gluon radiation spectrum off a highly energetic quark traversing a hot and dense QCD medium. But the study of the interference effects, the building block of the QCD jet calculation in vacuum, between different radiators has been missing for quite a long time. In this work we calculate, in the eikonal...
Andrej Ficnar
(Columbia University, New York, USA)
5/27/11, 3:20 PM
We investigate the connection between the conformal anomaly in the confinement transition region and quenching of heavy and light quarks in heavy ion collisions at RHIC and LHC by using a new non-conformal holographic model with a dilaton field. Holographic thermodynamic properties of the sQGP are constrained by lattice QCD calculations. The string drag force model of jets is generalized to...
Dr
Panos Christakoglou
(NIKHEF - Utrecht University)
5/27/11, 3:40 PM
Separation of charges along the extreme magnetic field created in non-central relativistic heavy-ion collisions is predicted to be a signature of local parity violation in strong interactions. We report on results for charge dependent two particle azimuthal correlations with respect to the reaction plane for Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$~TeV recorded in 2010 with ALICE at the LHC....
Prof.
Dirk Rischke
(Institut fur Theoretische Physik, Goethe University, and Frankfurt Institute for Advanced Studies (FIAS), 60438 Frankfurt am Main, Germany)
5/27/11, 3:40 PM
Using linear response theory, we derive [1] conditions for the retarded Green's function so that the linearized equation of motion of a dissipative current is reduced to a relaxation-type equation of the Israel-Stewart type [2]. We prove that this reduction can be done, if the singularity of the retarded Green's function closest to the origin is a simple pole on the imaginary axis. The...
Barbara Betz
(Columbia University)
5/27/11, 3:40 PM
While 2nd Fourier harmonics of jet quenching have been thoroughly explored in the literature and shown to be sensitive to (1) the underlying jet path length dependence of energy loss and (2) the differences between the mean eccentricity predicted by Glauber and CGC/KLN models of initial conditions, the sensitivity of higher harmonics, v_n(p_T, b), to differences between the fluctuation...
J. Matthew Durham
(Stony Brook University)
5/27/11, 3:40 PM
Throughout the history of the RHIC physics program, questions concerning the dynamics of heavy quarks have generated much experimental and theoretical investigation. A major focus of the PHENIX experiment is the measurement of these quarks through their semi-leptonic decay channels at mid and forward rapidity.
Heavy quark measurements in p+p collisions give information on the...
Derek Teaney
(Stony Brook University)
5/27/11, 4:00 PM
We give a simple recipe for computing dissipation
and fluctuations (commutator and anti-commutator correlation functions) for non-equilibrium black hole geometries. The recipe
formulates Hawking radiation as an initial value problem,
and is suitable for numerical work. We show how to package the fluctuation and
dissipation near the event horizon into correlators on the stretched...
Kolja Kauder
(University of Illinois at Chicago)
5/27/11, 4:00 PM
Hard scatterings of partons provide a valuable colored probe of the
strongly-coupled medium created in ultra-relativistic heavy ion
collisions. These hard scatterings can be studied by means of angular
correlations of charged hadrons with respect to a high transverse
momentum trigger particle. Several recent two-particle correlation
studies indicate that A+A collision dynamics evolve...
Dr
Yifei Zhang
(Lawrence Berkeley National Lab)
5/27/11, 4:00 PM
Heavy quark production in elementary particle collisions are expected to
be calculable in pQCD. In relativistic heavy ion collisions, heavy
quarks are believed to be an ideal probe to study the properties of the
created QCD medium. Early RHIC measurements were carried out mostly via
semi-leptonic decay electrons. There are limitations in the electron
approach: the charm hadron and...
Dhevan Gangadharan
(Department of Physics-Ohio State University)
5/27/11, 4:00 PM
Parity-odd domains from QCD are predicted to cause charge separation of quarks across the reaction-plane created in non-central relativistic heavy ion collisions--The Chiral Magnetic Effect [1]. Here we present several measurements to search for charge separation across the reaction-plane at STAR. We use three different observables: a three point correlator, a multiplicity asymmetry...
Peter Levai
(KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary)
5/27/11, 4:20 PM
The study of the nuclear suppression factor of charged hadrons and neutral pions in AuAu collisions at RHIC energies indicated the possible appearance of an anomaly at higher pT-s: although protons are expected to be produced from gluons, but jet energy loss is less effective for them comparing to pion suppression. Fragmentation function and jet energy loss based explanation can not reproduce...
Dr
Pietro Cortese
(Univ. del Piemonte Orientale, Dip.Scienze eTecnologie)
5/27/11, 4:20 PM
p-A collisions provide an essential reference for the study of J/psi suppression in heavy-ion data since they allow to evaluate cold nuclear matter effects. These include initial state effects like shadowing and parton energy loss and final state effects like J/psi breakup in the collisions with cold nuclear matter.
To evaluate these, NA60 has measured J/psi production in p-A collisions at...
Dr
Olaf Kaczmarek
(University of Bielefeld)
5/27/11, 4:20 PM
We report on a continuum extrapolation of the vector current correlation function for light valence quarks in the deconfined phase of quenched QCD. This is achieved by performing a systematic analysis of the influence of cut-off effects on light quark meson correlators at T=1.5 Tc using clover improved Wilson fermions [1]. In addition new results at 1.2 and 3.0 Tc will be presented.
The first...
Dr
Ilya Selyuzhenkov
(EMMI/GSI)
5/27/11, 4:20 PM
Azimuthal anisotropic flow is a key observable indicating collectivity among particles produced in non-central heavy ion collisions. Directed flow is characterized by the first harmonic coefficient in the Fourier decomposition of the particle azimuthal distribution with respect to the collision reaction plane. It develops at a very early stage of the collision and thus is sensitive to the...
Dr
Marco Monteno
(INFN Torino)
5/27/11, 4:40 PM
The understanding of the heavy-quark dynamics in nucleus-nucleus collisions, so far possible at RHIC only through the inclusive measurement of electron spectra from c and b decays, is becoming now accessible at LHC also through the exclusive reconstruction of open-charm hadrons, thus providing a richer physical information useful to discriminate among different theoretical models.
A complete...
Dr
Abhijit Majumder
(The Ohio State University)
5/27/11, 4:40 PM
We calculate the modification of hard jets in dense extended matter in the
higher-twist formalism. The single gluon emission spectrum from a hard quark due to multiple scattering in a medium is evaluated as a power series in inverse powers of the virtuality of the hard jet. Retaining corrections up to next to leading power, we calculate the medium modified fragmentation function by resumming...
Dr
Guo-Liang Ma
(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P.O. Box 800-204, Shanghai 201800, China)
5/27/11, 4:40 PM
Within the AMPT Monte Carlo model, fluctuations in the initial transverse parton density are shown to lead to harmonic flows. The net back-to-back dihadron azimuthal correlation after subtraction of contributions from harmonic flows still has a double peak that is independent of the initial geometric triangularity and unique to the jet-induced Mach cone and expanding hot spots distorted by...
Akihiko Monnai
(The University of Tokyo)
5/27/11, 4:40 PM
The heavy ion program at LHC opened up a new era in the physics of the quark-gluon plasma (QGP) at higher energies. One of the most unique properties of the hot matter is the near-perfect fluidity, which was first discovered in Au-Au collisions at RHIC [1]. Relativistic hydrodynamic analyses on the momentum anisotropy of transverse collective flow revealed that small viscosity in the QGP is...
Yetkin Yilmaz
(Massachusetts Inst. of Technology (MIT))
5/27/11, 5:30 PM
The energy loss of fast partons traversing the strongly interacting matter produced in high-energy nuclear collisions is one of the most interesting observables to probe the nature of the produced medium. Analyzing data from PbPb collisions at a center-of-mass energy of 2.76 TeV, recorded with the Compact Muon Solenoid (CMS) detector, parton energy loss is observed as a significant imbalance...
Sangyong Jeon
(McGill University)
5/27/11, 5:30 PM
I will present results for elliptic and triangular flow coefficients
v2 and v3 in Au+Au collisions at
sqrt(s) = 200A GeV using event-by-event 3+1D viscous hydrodynamic simulations. I will report on the effect of initial state fluctuations and finite viscosities on the flow coefficients v2 and v3 as functions of transverse momentum and pseudo-rapidity.
I will argue that simultaneous...
Dr
lokesh kumar
(Kent State University)
5/27/11, 5:30 PM
A current focus at RHIC is the Beam Energy Scan (BES) program to study the QCD phase diagram --- temperature ($T$) vs. baryon chemical potential ($\mu_B$). The BES program aims to verify some predictions from QCD: that a cross-over occurs at $\mu_B$ = 0, and that there exists a first-order phase transition at large $\mu_B$ and a critical point at an intermediate $\mu_B$. The spectra and ratios...
Yong Kim
(Massachusetts Inst. of Technology (MIT) Heacy Ion group (CMS))
5/27/11, 5:30 PM
In studies of the dense medium produced in ultra-relativistic heavy ion collisions, photons are important hard probes, since they are not expected to be modified by the medium. The measurement of isolated prompt photon production in PbPb collisions provides a test of perturbative quantum chromodynamics (pQCD) and the information to constrain the nuclear parton distribution functions. CMS has...
Xiaoyang Gong
(Stony Brook University)
5/27/11, 5:50 PM
A central goal in experimental nuclear physics is to map out the QCD phase diagram, and to measure precisely the properties of the different phases. In order to achieve this goal, RHIC has embarked on an energy scan program involving gold nuclei at various energies. The data collected by the PHENIX experiment for this program consists of data sets obtained at $\sqrt{s_{NN}}$ = 200, 62, 39 and...
Alexandru Florin Dobrin
(Wayne State University)
5/27/11, 5:50 PM
As a consequence of the energy loss of highly energetic parton propagating through a dense medium, jet quenching is an important probe of QGP created in high energy heavy-ion collisions. Jet quenching leads to the suppression of particle production at high transverse momenta. An observable that can be used to better constrain the mechanism responsible for the parton energy loss is the elliptic...
Guang-You Qin
(Duke University)
5/27/11, 5:50 PM
We study the evolution of a partonic jet shower propagating through a hot quark-gluon plasma. A differential equation is derived the evolution of the radiated gluon distribution as the jet propagates through the medium. Combined with the in-medium evolution of the leading parton, we compute the depletion of the energy from the jet cone by dissipation through elastic collisions with medium...
Dr
Antonio Uras
(INFN Cagliari, IPNL Lyon)
5/27/11, 5:50 PM
The study of the production of low mass vector and pseudoscalar mesons in proton-nucleus collisions represents a natural baseline for the heavy-ion observations, allowing to provide a reference in an environment of cold nuclear matter. In-medium modifications of the vector meson spectral functions were actually predicted to occur also in cold nuclear matter, though the experimental evidence at...
Jason Kamin
(State University of New York at Stony Brook)
5/27/11, 6:10 PM
Electron-positron pairs are effective probes for investigating the
hot, dense matter created in RHIC collisions because they are carry no
color charge and therefore, once created, do not interact strongly
with the medium. As a result, they retain characteristics of the full
time evolution and dynamics of the system. Among the many features,
the low mass region (m<1 GeV/c2) consists...
Alice Ohlson
(Yale University)
5/27/11, 6:10 PM
In recent years, the study of dihadron correlations has been one of the primary methods used to investigate the propagation and modification of hard-scattered partons in the QGP. Due to recent advancements in jet-finding algorithms it is now possible to use reconstructed jets in these correlation studies. This increases the kinematic reach of such analyses and improves the...
Prof.
Misha Stephanov
(UIC)
5/27/11, 6:10 PM
Observables measuring the magnitude and non-Gaussianity of event-by-event fluctuations can be used to discover the QCD critical point in heavy-ion collisions. I shall describe theoretical predictions for the non-Gaussian measures such as skewness, kurtosis and corresponding mixed moments as a function of the beam energy in the presence of the QCD critical point. I shall discuss implications...
Dr
Stefan Floerchinger
(CERN)
5/27/11, 6:10 PM
For large Reynolds number (which is inverse to viscosity), fluids are known to develop turbulence. Therefore, the phenomenological evidence for a small viscosity suggests that the hydrodynamical description of heavy ion collisions may have a turbulent regime. Assuming that averaged velocities are described by Bjorkens model, we investigate local fluctuations around it. These perturbations are...
Christopher Anson
(The Ohio State University)
5/27/11, 6:30 PM
Non-central heavy ion collisions at RHIC create an anisotropic participant zone of QCD matter under extreme conditions of energy and matter density. While this zone is initially out-of-plane-extended, pressure gradients cause the hot, dense medium to expand preferentially in plane. Over time, this expansion makes the shape more spherical, perhaps even becoming extended in the in-plane...
Andrej Kugler
(Nuclear Physics Institute)
5/27/11, 6:30 PM
In the energy domain of 1-2 GeV kinetic energy per nucleon, HADES has been performed systematic studies of electron-positron production in C+C, Ar+KCl, p+p, d+p and p+Nb collisions. Our results demonstrate that electron pair emission in small collision systems, such as C+C, can essentially be explained as a superposition of independent N+N collisions with a dominant contribution from the p-n...
Dr
Clément Gombeaud
(University of Bielefeld), Prof.
Nicolas Borghini
(University of Bielefeld)
5/27/11, 6:30 PM
Novel analytical results for the anisotropic collective flow of massive particles with a small interaction cross-section are presented. In particular, we show that, even when particles rescatter at most once, a sizable elliptic flow $v_2$ is generated, with mass ordering of the various particle species.
Mr
Jussi Auvinen
(University of Jyväskylä)
5/27/11, 6:30 PM
We examine the significance of elastic collisions as the suppression mechanism of high-energy partons in the strongly interacting medium formed in ultrarelativistic heavy ion collisions. For this purpose, we have developed a Monte Carlo simulation describing the interactions of perturbatively produced, non-eikonally propagating high-energy partons with the quarks and gluons from the expanding...
Bronislav Zakharov
(Landau Institute)
5/27/11, 6:50 PM
We study the nuclear modification factor R_AA at RHIC and LHC energies. We account for the radiative and collisional energy losses. Both the contributions are calculated with running \alpha_s accounting for fluctuations of the jet path lengths. The effect of the thermal suppression of \alpha_s is investigated. Comparison of the theoretical results with the experimental data obtained at RHIC...
Prof.
Fuming Liu
(Huazhong Normal University)
5/27/11, 6:50 PM
We predict that direct photon production in pp collisions at 7~TeV
will get at least 10 times enhanced compared to the next to leading
order pQCD predictions, at low transverse momentum ($\pt$ $\lesssim$
10~GeV/c), due to the thermal photon emissions from a quark gluon plasma
(QGP) formed in high multiplicity events. Thus the enhancement of
direct photon production at low $\pt$ can be a...
Norbert Novitzky
(Department of Physics-University of Jyvaskyla)
5/27/11, 6:50 PM
The suppression of inclusive pion production by up to a factor of 5, which was first observed in Au + Au at √sNN= 130 GeV/c (e.g. [1]) and later in Au + Au at √sNN= 200 GeV/c [2, 3], is one of the most significant manifestations of the opaque QGP produced in heavy ion collisions. The absence of this suppression in d + Au collisions at the same energy indicates the final state nature of the...
Denes Molnar
(Purdue University)
5/27/11, 6:50 PM
Much of our understanding of the collision dynamics at RHIC and LHC relies
on contrasting hydrodynamic or hydro+transport calculations with
experimental data. For example, early evidence for rapid thermalization
and quark-gluon plasma phase transition at RHIC came from particle spectra
and the pion-proton splitting of differential elliptic flow. An inevitable
component in these...
Dr
Yukinao Akamatsu
(Nagoya University)
5/27/11, 7:10 PM
We propose a novel relation between the low-mass enhancement of dielectrons observed at PHENIX and transport coefficients of QGP such as the charge diffusion constant D and the relaxation time \tau. The observed low-mass enhancement sets a lower-bound on the diffusion constant, D > 2/T, with T being temperature.
To reach this lower bound, we start with the second-order...
Dr
Chiara Oppedisano
(INFN, Sezione di Torino)
5/27/11, 7:10 PM
Electromagnetic dissociation of heavy nuclei in ultra-peripheral interactions at high energies can be used to monitor the beam luminosity at colliders.
Neutrons emitted by the excited nuclei close to beam rapidity are detected by the ALICE Zero Degree Calorimeters (ZDC) with full acceptance, providing a precise measurement of the event rate.
During the 2010 Pb-Pb run, a dedicated data...
Marlene Nahrgang
(Goethe University Frankfurt and Frankfurt Institute for Advanced Studies (FIAS))
5/27/11, 7:10 PM
We explore the potential of net-baryon, net-proton and net-charge
kurtosis measurements to investigate the properties of hot and dense
matter created in relativistic heavy-ion collisions. Contrary to
calculations in a grand canonical ensemble we explicitly take into
account exact electric and baryon charge conservation on an
event-by-event basis. This drastically limits the width of...
Marcus Bleicher
(Uni Frankfurt)
5/28/11, 9:30 AM
Carlos Albert Salgado Lopez
(Universidade de Santiago de Compostela)
5/28/11, 10:00 AM
Anna Stasto
(Penn State University)
5/28/11, 10:30 AM
Federico Antinori
(INFN Padova, Italy)
5/28/11, 11:00 AM
David Tlusty
(NPI ASCR)
Heavy flavor and quarkonia production
Poster
The charm production is sensitive to early dynamics of the created system
in RHIC heavy ion collisions. Dominant process of charm quark production
at RHIC is believed to be initial gluon fusion which can be calculated in the
perturbative QCD. Understanding both the charm production total cross
section and the fragmentation in p+p collisions is a baseline to
further explore the QCD medium...
Hermes Leon Vargas
(IKF Goethe-Universität Frankfurt am Main)
Jets
Poster
Studies of the inclusive jet production in Pb-Pb collisions at $\sqrt{s}$ = $2.76$ TeV and its possible modification by the hot and dense medium, require a comparison of the measured jet spectrum to that from pp collisions at the same center of mass energy. The goal of our study is to validate a reference spectrum obtained via Pythia simulations, using jet cross section measurements at the...
Mickey Chiu
(Brookhaven National Lab)
Experiments upgrade, future facilities and instrumentations
Poster
Recent developments in Time of Flight Detector (TOF) technology have made it possible to achieve timing resolutions of close to 10 ps. Much more development needs to be done, particularly in producing electronics with picosecond resolutions at reasonable cost. We present recent R&D studies at Brookhaven National Lab which study the feasibility of building a detector using micro-channel plate...
Stefania Velica
(Faculty of Physics, University of Bucharest)
Correlations and fluctuations
Poster
The study of the correlations among the particles emitted from the overlapping region of the colliding nuclei gives the information about the conditions in the early stage of the collision and the system evolution. The analysis of correlations and fluctuations in the relativistic nuclear collisions addresses fundamental aspects of the quantum chromodynamics (QCD) and, therefore, to the...
Mr
Martijn Reicher
(Universiteit Utrecht), Mr
Sanjib Muhuri
(Variable Energy Cyclotron Centre; Department of Atomic Energy; Government of India; 1/AF, Salt-Lake, Bidhan-nagar; Kolkata--64.), Mr
Tomoya Tsuji
(Center for Nuclear Study University of Tokyo)
Experiments upgrade, future facilities and instrumentations
Poster
As an upgrade of the ALICE experiment at the CERN-LHC, we would like to build and install a Forward Electromagnetic Calorimeter (FoCal) to be placed in the pseudorapidity region of 2.5 < η < 4.5, at the position of the existing Photon Multiplicity Detector (PMD). The basic motivation of including the calorimeter in the forward direction is to study outstanding fundamental QCD problems at low...
Dr
Aihong Tang
(Brookhaven National Laboratory)
Experiments upgrade, future facilities and instrumentations
Poster
In order to utilize the high luminosity provided by RHIC and the
enhanced data acquisition capability of STAR, a High Level online
tracking Trigger (HLT) is being developed to effectively study the
properties of the QGP created at RHIC. Based on the fast tracking and
event assembling, the STAR HLT can select events of great physics
interest online, which will reduce the rate to tape as...
Xianbao Yuan
(University and INFN, Padova, Italy - Institute of Particle Physics, Central China Normal University)
Heavy flavor and quarkonia production
Poster
ALICE is a general-purpose heavy-ion experiment designed to study
the physics of strongly interacting matter and the quark gluon-plasma in nucleus-nucleus collisions at the LHC.
The measurement of open charm and open beauty production allows
one to investigate the mechanisms of heavy-quark production,
propagation and, at low momenta, hadronisation in the hot and dense
medium formed in...
Dmitry Blau
(RRC Kurchatov Institute)
Global and collective dynamics
Poster
The measurement of the azimuthal anisotropy of neutral pions at high
transverse momentum helps unveil the path-length dependence of
jet-quenching. A further motivation to study this anisotropy at LHC
energies is given by the fact that the azimuthal anisotropy of neutral pions at RHIC is under-predicted by current QCD energy-loss
calculations. The neutral pion yield as a function of the...
Nicolas Arbor
(LPSC, UJF Grenoble 1, CNRS/IN2P3, INPG)
Jets
Poster
Measurements of the azimuthal correlation between high momentum photons or π0 and charged hadrons allow to investigate parton fragmentation following hard collisions, which will provide new
insights on medium effects. We present the experimental analysis which has been applied to the 2010 proton-proton collisions at √s = 7 TeV by the ALICE collaboration. The technique is based on...
Collaboration CMS
(UCLouvain)
Heavy flavor and quarkonia production
Poster
Measuring open heavy flavor at $\sqrt(s_{NN})=2.76$~TeV will test the theoretical calculations on the $J/\psi$ suppression at RHIC compared to LHC. With the CMS high resolution tracking, we are able to separate prompt $J/\psi$ from non-prompt $J/\psi$ in heavy ion collisions, thus disentangling yield modifications on primary J\$\psi$ from those coming from Bs that decay outside the medium. The...
Jon-Ivar Skullerud
(National University of Ireland Maynooth)
Heavy flavor and quarkonia production
Poster
We study the temperature dependence of bottomonium for temperatures in the range $0.4 T_c < T < 2.1 T_c$, using nonrelativistic dynamics for the bottom quark and full relativistic lattice QCD simulations for $N_f=2$ light flavors on a highly anisotropic lattice. We find that the $\Upsilon$ is insensitive to the temperature in this range, while the $\chi_b$ propagators show a crossover from the...
Kevin Dusling
(North Carolina State University)
Global and collective dynamics
Poster
In this work we examine the bulk viscous correction to the distribution function ($\delta f$) in both the relaxation time approximation and from weakly coupled QCD. We then incorporate this bulk viscous correction in 2+1 Dimensional viscous relativistic hydrodynamics and compute particle spectra and elliptic flow. Since the thermal mass for quark and gluons are different the departures from...
Juan Torres-Rincon
(Universidad Complutense de Madrid)
Global and collective dynamics
Poster
We address the bulk viscosity of a pion gas in kinetic theory.
Using Unitarized Chiral Perturbation Theory for the pion interaction we show how elastic collisions control the bulk viscosity at low
temperature and physical pion masses. The bulk viscosity vanishes in the limit of zero temperature, in agreement with non-relativistic arguments. The collision integral zero modes (corresponding to...
Sreekanth V.
(Physical Research Laboratory, Ahmedabad, India)
Electromagnetic probes
Poster
We investigate the thermal dilepton production-rates using one dimensional boost-invariant second order relativistic hydrodynamics to find proper time evolution of the energy density and the temperature. We study the \textit{non-ideal} effects arising due to viscosity (both bulk and shear), equation of state ($\epsilon\neq 3P$) and cavitation on thermal dilepton production from QGP at RHIC...
Antoine Lardeux
(SUBATECH, on behalf of the ALICE collaboration)
Heavy flavor and quarkonia production
Poster
The study of the J/ψ production and open heavy flavors in central Pb-Pb collisions is a promising tool to probe the properties of QGP in ALICE experiment at LHC.
To conduct this experimental study, it is necessary to know well the response fonction of the detectors used, in particular, the forward muon spectrometer to detect quarkonium and heavy flavour in their muonic channel. In this sense,...
Prof.
Joerg Aichelin
(subatech)
Global and collective dynamics
Poster
To understand the centrality dependence of the measured observables, like the multiplicity $<p_t>^$ and the elliptic flow of identified particles at midrapidity as well as the elliptic flow of charges hadrons, has been a challenge for theory since many years. Although the multiplicity of different particles in central collisions corresponds exactly to the expectation for a completely...
Rosi Reed
(STAR)
Heavy flavor and quarkonia production
Poster
Suppression of quarkonia in heavy ion collisions with respect to proton-proton collisions was hypothesized to be a signature of the Quark Gluon Plasma (QGP). However, effects such as the statistical recombination of heavy flavor quark-antiquark pairs or co-mover absorption can also affect quarkonia production. For the bottomonium states these competing effects are expected to be smaller than...
Dr
Asis Chaudhuri
(Variable Energy Cyclotron Centre), Dr
Bikash Sinha
(Variable Energy Cyclotron Centre)
Global and collective dynamics
Poster
Extensive analysis of RHIC data at $\sqrt{s}_{NN}$=200 GeV Au+Au collisions has provided convincing evidence that Quark Gluon Plasma (QGP) produced in such a collision behaves almost like a perfect fluid with viscosity per specific enropy $\eta/s$ is around the lower bound as per AdS/CFT $\eta/s=1/4\pi$. Recently, ALICE collaboration has come out with the data for elliptic flow as a function...
santosh K das
(Variable Energy Cyclotron Centre)
Heavy flavor and quarkonia production
Poster
The drag and diffusion coefficients of charm and bottom quarks propagating
through quark gluon plasma (QGP) have been evaluated for conditions
relevant to nuclear collisions at Large Hadron Collider (LHC)
and at Relativistic Heavy Ion Collision (RHIC).
The dead cone and Landau-Pomeronchuk-Migdal (LPM) effects on
radiative energy loss of heavy quarks have been considered.
Both...
Sören Schlichting
(Technische Universität Darmstadt)
Correlations and fluctuations
Poster
We study charged particle correlations in a thermal freeze-out model with local charge conservation. By comparison to STAR data we find that balancing charges are emitted from significantly smaller rapidity regions in central collisions compared to peripheral collisions. The results indicate that charge diffusion is small and the centrality dependence points to a change of the charge...
Satyajit Jena
(IIT Bombay)
Correlations and fluctuations
Poster
Charge fluctuations are considered to provide a possible signature for the existence of the de-confined Quark Gluon Plasma phase (QGP). Charge fluctuations are sensitive to the number of charges in the system, thus the fluctuations in the QGP, with fractionally charged partons, are significantly different from those of hadron gas with unit charged particles [1,2]. The study of charge...
Prithwish (for the STAR collaboration) Tribedy
(Variable Energy Cyclotron Centre)
Correlations and fluctuations
Poster
Event-by-event fluctuation of the ratio of multiplicities of
charged and neutral particles at forward rapidity in AuAu collisions at \sqrt{s_NN}=200 GeV has been studied. As the detected charged and
neutral particles are mostly from the charged pions and the decay of
neutral pions respectively, this analysis addresses isospin fluctuation of pions predicted to occur for a system going...
Dr
Ludmila Malinina
(Joint Inst. for Nuclear Research (JINR)-Unknown-Unknown)
Correlations and fluctuations
Poster
Charged KK femtoscopy correlations from 7 TeV pp collisions
measured by ALICE collaboration.
L. Malinina (SINP MSU-JINR) for the ALICE collaboration
We report on the results of charged kaon femtoscopy analysis of the 7 TeV pp collisions at the LHC in the ALICE experiment. KK correlation functions are constructed in 3 multiplicity and 4 kt bins. The KK source parameters are extracted by...
Dr
Dong Jo Kim
(University of Jyväskylä)
Global and collective dynamics
Poster
The centrality dependence of nuclear modification factor($R_{AA}$) carries information about the path-length variation of partonic energy loss. However, the inclusive $R_{AA}$ for a given centrality emerges by averaging over different path lengths as the overlap zone of two colliding nuclei has typically a nearly elliptical shape in the transverse plane. The partons traversing the medium in...
Shikshit Gupta
(Department of Physics)
Hadron thermodynamics and chemistry
Poster
The ratios of particle production in hadronic interactions are important indicators of the collision dynamics [1]. These can be used to probe the process of hadronization in high energy collisions. We present measurements of mid-rapidity anti-particle to particle ratios in p + p collisions at √s = 62.4 GeV from the STAR experiment. The measurements of the anti-particle to particle ratios are...
Dr
Asis Chaudhuri
(Variable Energy Cyclotron Centre)
Global and collective dynamics
Poster
The azimuthal correlation of produced particles in the reaction plane or elliptic flow in heavy ion collision is a sensitive probe to (i) degree of thermalization (ii) transport coefficient and (iii) the equation of state (EoS) of the medium. Recently, ALICE collaboration measured (differential) elliptic flow in √s=2.76 TeV Pb-Pb collision [1]. We have analyzed the elliptic flow data to...
Dr
Peter Christiansen
(Lund University)
Jets
Poster
The TPC is the main tracking detector in the central barrel ($|\eta|\leq 1$) of the ALICE experiment. In addition to tracking it provides particle identification through the measurement of the specific energy loss, dE/dx, which depends only on $\beta\gamma = p/m$. At low momentum, $p$<1GeV/c, pions, kaons, and protons, can be cleanly separated in different momentum intervals. At high momentum,...
Georg Wolschin
(Heidelberg University)
Hadron thermodynamics and chemistry
Poster
The energy dependence of charged-hadron production in relativistic heavy-ion collisions is investigated in a nonequilibrium-statistical relativistic diffusion model (RDM) with three sources [1]. Theoretical pseudorapidity distributions are compared with PHOBOS AuAu data [2] at RHIC energies of sqrt(s_NN) = 0.13 and 0.2 TeV including the centrality dependence, and computed for PbPb central...
Christian Holm Christensen
(Niels Bohr Institute)
Global and collective dynamics
Poster
Anton Alkin
(Bogolyubov Inst. for Theor. Phys. (ITP)-Ukrainian Academy of Sci)
Global and collective dynamics
Poster
High-statistics measurements were performed at LHC, with the ALICE central barrel detectors, in the central pseudorapidity region (–1 ≤ η < 1) of multiplicity distributions, and pseudorapidity densities of primary charged particles produced in proton–proton collisions, at √s = 0.9 TeV, 2.76 TeV and 7 TeV.
Measurements were obtained for two event classes: inelastic events (INEL) and...
Michael Linus Knichel
(Research Division and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany)
Global and collective dynamics
Poster
Inclusive charged-particle transverse momentum distributions have been measured in proton-proton collisions at √s = 0.9, 2.76 and 7 TeV with the ALICE detector at the LHC. The measurements in the central pseudorapidity region |η| < 0.8 cover a transverse momentum range of 0.15 < p_T < 50 GeV/c. The evolution of the transverse momentum spectra as a function of the collision energy and the...
Thomas Lang
(Frankfurt Institute for Advanced Studies)
Heavy flavor and quarkonia production
Poster
We study charmonium physics in heavy-ion collisions within the framework
of the non-equilibrium transport model UrQMD.
Using this model we compute different heavy quark observables like the
nuclear modification factor $R_{AA}$, high $p_T$ suppression and the
elliptic flow $v_2$.
The UrQMD approach includes explicit interactions of the charmed particles
with the surrounding...
Dr
Kenji Morita
(Kyot University)
Heavy flavor and quarkonia production
Poster
Charmonia in medium provide us information on the change of the confinement
property induced by the medium. We have developed an approach based on
QCD sum rule which connects temperature dependent QCD condensates to
the spectral function through the operator product expansion of the
current correlation function.
The leading contribution to the OPE is the dimension four gluon...
Prof.
Alexeii Kurepin
(Institute for Nuclear Research (INR))
Experiments upgrade, future facilities and instrumentations
Poster
Charmonium production on fixed target with proton and lead beams of LHC.
A.B.Kurepin, N.S.Topilskaya, M.B.Golubeva
Institute for Nuclear Research of the Russian Academy of Sciences,
117312 Moscow, Russia
Fixed target operation with proton and lead beams of LHC provides new possibilities for investigation of a mechanism of quarkonium production and suppression...
Rashid Khan
(Norwegian University of Science and Technology)
QCD phase diagram
Poster
We study the quark-meson model with two quark flavors in a strong external magnetic field at finite temperature and finite baryon chemical potential.We calculate the full renormalized effective potential to one loop order in perturbation theory.While the critical temperature in the chiral limit is almost unchanged and compared to the case with zero external magnetic field, the transition is...
Matthew Wysocki
(University of Colorado Boulder)
Heavy flavor and quarkonia production
Poster
The production of heavy quarkonia in high-energy nuclear collisions is a problem that is still poorly understood, even without the presence of the quark-gluon plasma. The most common method of calculation is with nuclear-modified parton distribution functions and a break-up cross section for the (pre-J/psi) c-cbar pair passing through the nucleus. Calculations of this nature will be...
Ryohji Akimoto
(University of Tokyo)
Experiments upgrade, future facilities and instrumentations
Poster
Heavy quarks (charm and bottom) is one of the key probes to study properties of Quark Gluon Plasma (QGP). A silicon vertex tracker (VTX) has been developed for RHIC-PHENIX experiment mainly for the measurement of the heavy quarks. It enables to measure tracks of charged particles precisely enough to evaluate yields of charm and bottom individually and therefore is an essential tool to study...
Dr
MAKI KUROSAWA
(RIKEN)
Experiments upgrade, future facilities and instrumentations
Poster
The PHENIX detector had been upgraded with the silicon vertex tracker (VTX) to extend its physics capability in both the heavy ion and spin programs at Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The main role of VTX is precision measurement of heavy flavor.
The VTX comprises a four-layer barrel detector built from two inner silicon pixel detector and two outer...
Darren McGlinchey
(Florida State University)
Heavy flavor and quarkonia production
Poster
Recent results from PHENIX on $J/\psi$ production in d+Au collisions
have shown that $J/\psi$'s are significantly suppressed at forward
rapidity. This has interesting implications for $J/\psi$ suppression in Au+Au collisions, and may provide an answer to the $J/\psi$ puzzle. We try to constrain these cold nuclear matter (CNM) effects by fitting the EPS09 parametrization plus a break-up cross...
Dr
Takashi Hachiya
(RIKEN)
Experiments upgrade, future facilities and instrumentations
Poster
A silicon vertex tracker (VTX) is one of the upgrade programs
in the PHENIX experiment to measure the production of
heavy (charm and bottom) quarks in Au+Au and polarized p+p collisions.
The production of heavy quarks is a powerful tool
to study both the properties of a dense partonic matter created in
high energy heavy ion collisions and the gluon contribution to
the spin structure of...
Dr
Wolfgang Unger
(ETH Zürich)
QCD phase diagram
Poster
We present results for QCD in the strong coupling limit, obtained from a worm-type algorithm on a discrete spatial lattice but with continuous Euclidean time. This is obtained by sending both the anisotropy parameter $\gamma^2=a/a_t$ and $N_\tau$ to infinity at fixed temperature $T=\gamma^2/N_\tau$. The gain is that no continuum extrapolation for $N_\tau \rightarrow \infty$ has to be carried...
Dr
Boris Tomasik
(Czech Technical University in Prague - Prague - Czech Republic)
Global and collective dynamics
Poster
Large number of semi-hard partons deposit their energy and momentum in nuclear collisions at the LHC. Hereby they can induce collectively moving streams within the hydrodynamically behaving bulk matter. Although the production of hard partons is isotropic, in non-central collisions we have an anisotropy of their spatial distribution. We argue that via the interaction of the produced streams...
Dr
Oana Ristea
(University of Bucharest, Faculty of Physics)
Experiments upgrade, future facilities and instrumentations
Poster
At AGS and SPS energies, the ratio of negative to positive pions at low pion transverse momenta reflects the effect of Coulomb repulsion, because the charged particles, especially pions, are highly influenced by the Coulomb field produced by the net charge of the reaction protons. The interaction between charged pions and net charged of protons changes the transverse momentum of pions with a...
Prof.
Yuanfang Wu
(Institute of Particle Physics, Huazhong Normal University)
QCD phase diagram
Poster
Binder-like ratios of baryon number are firstly suggested in relativistic heavy ion collisions. Using 3D-Ising(O(1)), O(2), and O(4) models, the critical behavior of Binder-like ratios and ratios of higher cumulants of order parameter are fully presented. Binder-like ratio is shown to be a step function of temperature. The critical point is the intersection of the ratios of different system...
Dr
Grelli Alessandro
(Utrecht University)
Heavy flavor and quarkonia production
Poster
Heavy quark production provides a powerful tool to test pQCD calculations in hadron collisions in the new energy regime of the LHC. Moreover the D meson pt-differential cross section in pp collisions provides the reference for the study of nuclear matter effects on charm quarks in PbPb collisions, via the nuclear modification factor.
The ALICE experiment collected data in pp collisions at...
Zaida Conesa Del Valle
(CERN)
Heavy flavor and quarkonia production
Poster
The ALICE experiment has the ability to measure D meson production in different colliding systems. Charm production in proton proton collisions is an important tool to test pQCD calculations in a new energy domain. Its spectrum in heavy ion interactions is influenced by the formation of hot and dense QCD matter.
A common procedure to study the characteristics and effects of this matter is to...
Giacomo Ortona
(Universita & INFN, Torino)
Heavy flavor and quarkonia production
Poster
A Large Ion Collider Experiment (ALICE) is one of the four experiments at the Large Hadron Collider (LHC), and the only one mainly dedicated to ultra relativistic heavy ion collisions, in order to investigate the properties of the high-density state of QCD matter produced in such events. The first Pb-Pb collisions at a centre of mass energy of √s = 2.76 TeV for nucleon pair were delivered by...
Dr
Bala Renu
(INFN,Turin)
Heavy flavor and quarkonia production
Poster
ALICE is the dedicated heavy-ion experiment at the LHC. Its main physics goal is to study the properties of the strongly-interacting matter in the conditions of high energy density (>10 GeV/fm3 ) and high temperature (> 0.3 GeV) expected to be reached in central Pb-Pb collisions. Charm and beauty quarks are a powerful tool to investigate this high density and strongly interacting state of...
Chiara Bianchin
(Universita degli Studi di Padova-Universita & INFN, Padova-Unkn)
Heavy flavor and quarkonia production
Poster
The ALICE experiment at LHC studies p-p and Pb-Pb collisions with the aim of investigating the properties of the high-density state of strongly-interacting matter, expected to be produced in Pb-Pb collisions.
D mesons are powerful probes of the medium since the charm quark is produced in a very short time scale and experiences all the evolution of the collision.
The measurement of the...
Collaboration CMS
(UCLouvain)
Heavy flavor and quarkonia production
Poster
CMS has been collecting single muon triggered data in 2010 at $\sqrt{s_{NN}} = 2.76$~TeV in PbPb in order to extract from real data efficiency corrections for muon based analysis. These results were used as an important cross-check for the Monte-Carlo based efficiency corrections used for the Z boson and quarkonia analysis in PbPb and taken into account in the systematics. This poster will...
Dr
Topi Kahara
(Helsinki Institute of Physics)
QCD at high temperature and density
Poster
We study the interaction between the chiral and deconfinement transitions using effective models such as the Polyakov extended linear sigma model and the Nambu-Jona-Lasinio model. In this talk we consider fermions in higher representations of both SU(2) and SU(3) gauge groups. Our results motivate further studies of these theories on the lattice and they are also relevant for models of...
Alexey Stavinskiy
(ITEP)
Experiments upgrade, future facilities and instrumentations
Poster
New phase diagram sector at extrimely large baryon density and low temperature is proposed for the laboratory study at TWA(ITEP),Nuclotron-M,MPD-NICA(JINR), CBM@SIS100(FAIR). High pt central rapidity double cumulative trigger for this study is proposed and tested experimentally at ITEP ion accelerator by FLINT collaboration.FLINT experiment is dedicated to the research program of dense cold...
Prof.
Teiji Kunihiro
(Kyoto University)
Global and collective dynamics
Poster
This is an extention of our previous work[1,2] to the derivation of the causal relativistic hydrodynamic equations in generic local rest frames for a viscous fluid from the relativistic Boltzmann equation. Our derivation is based on the renormalization group method[3] as a powerful reduction theory of the dynamics. We have identified some drawbacks in our previous derivation
of the casusal...
Dr
Song Shu
(Faculty of Physics and Electronic Technology, Hubei University, China)
QCD phase diagram
Poster
The FL model is studied at finite temperature and density. The
soliton solutions of the FL model in deconfinement phase
transition are solved and thoroughly discussed for certain
boundary conditions. We indicate that the solitons before and
after the deconfinement have different physical meanings: the
soliton before deconfinement represents hadron, while the soliton
after the...
Gyulnara Eyyubova
(University of Oslo)
Global and collective dynamics
Poster
Directed flow serves as one of the key observable to understand the
properties of the hot and dense matter produced in ion-ion collisions.
We report on systematics and detector effects study in the directed
flow measurement using the reaction plane estimate provided by the
sidewards deflection of neutral spectators measured with the help of ALICE Zero Degree Calorimeter detectors.
Effects...
Dr
Tariq Mahmoud
(Universität Gießen)
Experiments upgrade, future facilities and instrumentations
Poster
The Compressed Baryonic Matter (CBM) experiment is the future heavy-ion experiment at FAIR being designed to explore the intermediate range of the QCD phase diagram in a beam energy interval of 10-45 AGeV. With its physics program CBM will investigate the properties of dense baryonic matter and the expected phase transition between hadronic and partonic matter. Among the key observables are...
Alexeii Kurepin
(Institute for Nuclear Research (INR))
Experiments upgrade, future facilities and instrumentations
Poster
Development of the FARICH detector as a possible
upgrade for ALICE HMPID system
A.B. Kurepin a, A.I. Reshetin a, A.F. Danilyuk c, D.A. Finogeev a,
T.L. Karavicheva a, E.V. Karpechev a, V.L. Kirillov c, S.A. Kononov b,
E.A. Kravchenko b, A.N. Kurepin a, A.I. Maevskaya a, Yu.V. Musienko a,
A.P. Onuchin b, V.I. Razin a, N.S.Topilskaya a, E.A.Usenkoa
a. ...
Ermias T. Atomssa
(Stony Brook University)
Electromagnetic probes
Poster
The di-electron spectrum is rich with physics signals that assist the characterisation of the medium created in A+A collisions. The measurement, especially at low mass, is however complex due to a very low signal to background ratio. PHENIX has shown in the past that despite this difficulty, it is possible to learn for example about open charm production [1] or direct photons [2].
The...
Patrick Huck
(CCNU + IKF + LBNL)
Electromagnetic probes
Poster
During the beam energy scan in 2010 a wide range of beam energies has been explored for Au+Au collisions using the STAR detector at RHIC. With minimum material budget in the tracking part of the detector this run is particularly suited for the investigation of virtual photons originating from the hot and dense medium created in heavy ion collisions. The completed installation of the STAR...
payal mohnaty
(Variable Energy Cyclotron Centre)
Electromagnetic probes
Poster
The Hanbury-Brown-Twiss (HBT) radii from the correlation functions of
the two virtual photons produced in the collisions of two nuclei at
ultra-relativistic energies have been evaluated. We show that a study of the mass dependence of various interferometry radii extracted from the correlation functions of virtual photons can be a powerful tool
to characterize and distinguish the hadronic...
Dr
Olena Linnyk
(University of Giessen)
Electromagnetic probes
Poster
We describe heavy-ion collisions from the initial phase of colliding nuclei in their groundstates throughout the interaction phase up to the final hadronic elastic and inelastic interactions as well as hadron decays using the nonequilibrium microscopic Parton-Hadron-String Dynamics (PHSD) transport approach, which includes the off-shell dynamics of quarks, antiquarks and gluons as well as a...
Prof.
Bikash Sinha
(Variable Energy Cyclotron Centre)
Electromagnetic probes
Poster
The invariant mass and transverse momentum spectra of lepton pairs
for In-In collision at $\sqrt{s_{\mathrm {NN}}}=17.3$ GeV have been studied.
We find that the broadening of the $\rho$ mesons spectral function
due to its interaction with the thermal baryons causes substantial
excess of dimuons at low mass region. Both the spectra agrees
well with the experimental observations made...
Dr
Elvira Santini
(Goethe Universität Frankfurt)
Electromagnetic probes
Poster
In this talk I discuss dilepton emission from hot and dense matter created in heavy-ion collisions and present results on dimuon invariant and transverse mass spectra obtained using a hybrid approach based on the UrQMD transport model with an intermediate hydrodynamic stage for the modeling of heavy-ion dynamics.
During the hydrodynamic stage, the production of lepton pairs is described by...
Dennis Perepelitsa
(Columbia University)
Jets
Poster
d+Au collisions at RHIC can be used to investigate cold nuclear matter effects on hard parton scattering. d+Au collisions at different centrality (different N_coll) can probe nuclear parton distributions, initial state energy loss and final state parton interactions in the cold nucleus. They also provide a valuable baseline for hard-scattering processes in heavy ion collisions. Measurements...
Dr
Bjørn Bäuchle
(Frankfurt Institute for Advanced Studies)
Electromagnetic probes
Poster
The microscopic transport model UrQMD and a micro+macro hybrid model are used to calculate direct photon spectra from A+A-collisions at FAIR- and RHIC-energies. In the hybrid model, the intermediate high-density part of the nuclear interaction is described with ideal 3+1-dimensional hydrodynamics, while the initial state and final state-scatterings are modelled in UrQMD. Different Equations of...
Iwona Wyskiel-Piekarska
(Institute of Nuclear Physics PAN)
Pre-equilibrium and initial state physics
Poster
For the first time, the generation of the directed flow of particles emitted from the fireball created in heavy-ion collisions at RHIC is described using a 3+1D hydrodynamical model. The initial fireball density is constructed as a sum of contributions from forward and backward going participants. This asymmetry in the
emission from the individual participants leads to a tilt of the source....
Dr
Fernando Gardim
(USP)
Global and collective dynamics
Poster
Fluctuations in the initial geometry of a nucleus-nucleus
collision have been recently shown to produce the correlation
structures known as ``ridge" and ``shoulder". These event-by-event
fluctuations result in new types of anisotropic flow, such as
triangular flow $v_3$ and a new type of directed flow $v_1$,
which, unlike the usual directed flow, is also present at
midrapidity. The...
Yadav Pandit
(For the STAR Collaboration)
Global and collective dynamics
Poster
Measurements of anisotropic flow in heavy-ion collisions
provide insight into the early stage of the system's
evolution. Directed flow, $v_1$, is imparted especially
early. A change of sign in the slope of $dv_1/dy$ for
identified particles, particularly for protons, has been
suggested as a possible signal of a first-order phase
transition. In this talk, we present the STAR measurements...
Dr
Mauricio Martinez Guerrero
(FIAS)
Pre-equilibrium and initial state physics
Poster
We present a method to improve the description of 0+1 dimensional boost
invariant dissipative dynamics in the presence of large momentum-space
anisotropies. Instead of using the canonical hydrodynamical expansion of the distribution function around an isotropic equilibrium state, we expand around a state which is anisotropic in momentum space and parameterize this state in terms of three...
payal mohnaty
(Variable Energy Cyclotron Centre)
Electromagnetic probes
Poster
The effects of the shear and the bulk viscosities
on the transverse momentum distribution of thermal photons
have been studied. The effects of viscosity have
been taken into account both in the phase space
distributions of the particles taking part in the
production process as well as in the space time
evolution. We argue that the thermal photons can be
...
Andrej El
(University of Frankfurt)
Global and collective dynamics
Poster
Novel set of second-order dissipative hydrodynamic equations for shear stress tensor of each
component of a multi-component mixture is derived using the entropy principle [1]. Summation over
the equations for all components leads to an effective relaxation-type one-component equation for
the total system. In this equation the effective shear viscosity (or alternatively the $\eta/s$
ratio)...
Dr
Koichi Hattori
(High Energy Accelerator Research Organization (KEK))
Correlations and fluctuations
Poster
The experiment by the ultrarelativistic heavy ion collisions has opened a novel insight into the extreme state of matter. Besides, it provides an opportunity to study the dynamics of strong Abelian and non-Abelian gauge fields. In peripheral collisions, an extremely strong Abelian magnetic field is created by two colliding heavy ions having large electric charges. The magnetic field has a much...
Santosh K Das
(Variable Energy Cyclotron Centre)
Heavy flavor and quarkonia production
Poster
We evaluate the drag and diffusion coefficients of a hot hadronic medium consisting of pions,
nucleons, kaons and eta using open charm mesons as a probe. The interaction of the probe with
the hadronic matter has been treated in the framework of effective field theory. It is observed that
the magnitude of both the transport coefficients are significant, indicating substantial amount...
Leticia Palhares
(CEA/Saclay)
QCD phase diagram
Poster
The linear sigma model with quarks at very low temperatures provides an effective description for the thermodynamics of the strong interaction in cold and dense matter, being especially useful at densities found in compact stars and protoneutron star matter. Using the MSbar one-loop effective potential, we compute quantities that are relevant in the process of nucleation of droplets of quark...
Vitalii Ozvenchuk
(FIAS)
Global and collective dynamics
Poster
I study the kinetic and chemical equilibration in `infinite' parton
matter within the Parton-Hadron-String Dynamics transport approach,
which is based on a dynamical quasiparticle model for partons
matched to reproduce lattice-QCD results -- including the partonic
equation of state -- in thermodynamic equilibrium. The `infinite'
matter is simulated within a cubic box with...
Alessandro Buzzatti
(Columbia University)
Jets
Poster
Perturbative magnetic scattering effects in the HTL approximation predict enhanced jet energy loss for both light and heavy quarks. Whereas this helps to reduce the discrepancy of pQCD tomography with single electron data at RHIC, the new computations reveal significant disagreement with pion quenching data due to overestimation of the quenching suffered by light jets. We discuss whether this...
Dr
Yuki Minami
(Japan)
Correlations and fluctuations
Poster
We study the critical dynamics near QCD critical point (CP)
by dynamic renormalization group (RG).
As a basic equation for the critical dynamics,
we construct the nonlinear Langevin equation,
which is a standard dynamic equation for a CP in condensed matter physics.
Our onstruction is based on the generalized Langevin equetion and the relativistic hydrodynamics.
Applying the dynamic...
Experiments upgrade, future facilities and instrumentations
Lusaka Bhattacharya
(Saha Institute of Nuclear Physics)
Electromagnetic probes
Poster
We discuss the role of collisional energy loss on high $p_T$ photon
data measured by PHENIX collaboration by calculating photon yield in
jet-plasma interaction. The phase space distribution of the
participating jet is dynamically evolved by solving Fokker-Planck
equation. We treat the strong coupling constant ($\alpha_s$) as function
of momentum and temperature while calculating the...
Collaboration CMS
(UCLouvain)
Heavy flavor and quarkonia production
Poster
Measuring $J/\psi$ polarization in heavy ion collisions requires a very high luminosity. While most of the LHC experiments have been quoting corrected yields in heavy ion collisions based on the assumption of an unpolarized production, CMS prefers to quote results in different scenarios, allowing theorists to confront their calculations in the frame they prefer. The effect of polarization on...
Bin Zhang
(Arkansas State University),
Guo-Liang Ma
(Shanghai Institute of Applied Physics)
Correlations and fluctuations
Poster
Charge separation is an important consequence of the Chiral Magnetic Effect. Within the framework of a multi-phase transport model, the effects of final state interactions on initial charge separation are studied. We demonstrate that charge separation can be significantly reduced by the evolution of the Quark-Gluon Plasma produced in relativistic heavy ion collisions. Hadronization and...
Bin Zhang
(Arkansas State University)
Pre-equilibrium and initial state physics
Poster
Radiative processes and dynamical screening are important for a precise description of the dynamics of relativistic heavy ion collisions. When evolutions from inside-outside and thermal initial conditions are compared, the parton system produced in relativistic heavy ion collisions is found to be able to overcome expansion and move toward thermalization via parton collisions. Scaling behaviors...
Dr
Maxim Chernodub
(University of Tours, France)
QCD phase diagram
Poster
Recently, we have suggested that the vacuum in a strong external magnetic field experiences a spontaneous phase transition to an electromagnetically superconducting state. The unexpected superconductivity of, basically, empty space is induced by emergence of quark-antiquark vector condensates with quantum numbers of electrically charged rho mesons. The ultra-periferal heavy-ion collisions...
Collaboration CMS
(UCLouvain)
Electromagnetic probes
Poster
We report on the measurement of Z boson production and decay in the di-electron channel in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV by the CMS experiment at the LHC. We observe about 30 events containing a pair of electrons which were reconstructed to form distinctive Z boson candidates. Z boson reconstruction in the electron channel is challenging due to the complexity of electron...
Dr
Volodymyr Konchakovski
(Institute for Theoretical Physics, Giessen University)
Global and collective dynamics
Poster
We present a systematic study of correlations in pseudorapidity and azimuthal angle for charged high transverse momentum hadrons in heavy-ion collisions at the top RHIC energy within the Parton-Hadron-String-Dynamics (PHSD) transport approach. The study shows that a significant part (60%) of the high-pT hadron attenuation seen experimentally can be attributed to inelastic interactions of...
Dr
Michael K. Mitrovski
(for the STAR collaboration)
Global and collective dynamics
Poster
The study of elliptic flow and non-flow effects over a wide energy range can provide information on the onset of collective effects in heavy-ion collisions. In 2010, STAR collected high statistics data samples at lower RHIC energies at $\sqrt{s_{NN}}$ = 7.7, 11.5 and 39 GeV. We will present measurements of charged particle elliptic flow using the event-plane ($v_{2}\{EP\}$) determined from...
Oeystein Djuvsland
(University of Bergen)
Jets
Poster
In ultra-relativistic heavy ion collisions at sufficiently large energy densities, a new state of strongly interacting matter is created, often referred to as the Quark Gluon Plasma (QGP).
The produced medium can be attributed a formation time, and a formed energy density can be estimated based on the transverse energy ($E_T$) produced in these collisions via the Bjorken
formula (Bjorken,...
Dr
KeJun Wu
(1. Institute of Particle Physics, Huazhong Normal University, Wuhan, 430079, China 2. The Key Laboratory of Quark and Lepton Physics (Huazhong Normal University) Ministry of Education, Wuhan, 430079, China)
QCD phase diagram
Poster
One of the most exciting goals for the field of the high-energy nuclear collisions is to understand the phase structure of matter with partonic degrees of freedom and the transition from partonic phase to hadronic phase. In this talk, we will utilize the elliptic flow (v2) as a tool to address phase boundary issue. The v2 reflects the early collision dynamics [1]. Using transport models AMPT...
Ondrej Chvala
(UCR Riverside)
Pre-equilibrium and initial state physics
Poster
Previous RHIC results have shown that high-$p_T$ mid-rapidity $\pi^0$ and $\eta$ mesons are suppressed in central Au+Au collisions while they are not in d+Au collisions. Furthermore, direct photons in Au+Au collisions appear mostly unsuppressed as well, with a possible exception at very high $p_T$. This leads to the picture of a hot and dense medium in the final state. Measurements of d+Au...
Saumia Pandiat
(Institute of Physics)
Global and collective dynamics
Poster
It is known that the presence of background magnetic field in cosmic
plasma distorts the acoustic peaks in CMBR. This primarily results from different types of waves in the plasma with velocities
depending on the angle between the magnetic field and the wave vector. We consider the consequences of these effects in relativistic heavy-ion collisions where very strong magnetic fields...
Yuji Sakai
(Kyushu University)
QCD phase diagram
Poster
We extend the Polyakov-loop extended Nambu–-Jona-Lasinio (PNJL) model by introducing an effective four-quark vertex depending on Polyakov loop. The effective vertex generates entanglement interactions between Polyakov loop and chiral condensate. The new model is consistent with lattice QCD data at imaginary quark number
chemical potential and real and imaginary isospin chemical potentials,...
Dr
Mate Csanad
(Eötvös University)
Global and collective dynamics
Poster
In gold-gold collisions of the Relativistic Heavy Ion Collider (RHIC) a perfect fluid of quarks, sometimes called the strongly interacting quark gluon plasma (sQGP) is created for an extremely short time. The time evolution of this fluid can be described by hydrodynamical models. After expansion and cooling, the freeze-out happens and hadrons are created. Their distribution reveals information...
Dr
binoy patra
(Indian Institute of Technology Roorkee)
Heavy flavor and quarkonia production
Poster
Recently we have developed the equation of state for a strongly interacting quark-gluon plasma in the framework of strongly-coupled QED plasma by incorporating the non-perturbative effects in
terms of nonzero string tension in the deconfined plasma phase,
unlike the Coulomb interactions alone.
Our results on thermodynamic observables
{\em viz.} pressure, energy density, speed of sound etc....
Prof.
Dinesh Srivastava
(Variable Energy Cyclotron Centre), Dr
Rupa Chatterjee
(University of Jyvaskyla),
Somnath De
(Variable Energy Cyclotron Centre)
Electromagnetic probes
Poster
We find that an equation of state for hot hadronic matter consisting of all baryons having $M < 2$ GeV and all mesons having $M < 1.5$ GeV, along with Hagedorn resonances in thermal and chemical equilibrium, matches rather smoothly with lattice equation of state (p4 action, ${N_\tau}=8$) for T up to $\approx 200$ MeV, when corrected for the finite volume of hadrons.
Next we construct two...
Prof.
Akira Ohnishi
(Kyoto University)
Global and collective dynamics
Poster
Understanding the mechanisms causing rapid thermalization deduced for
high-energy heavy ion collisions is still a challenge.
Thermalization is not fast enough in perturbative esitmate,
and several instabilities in the classical Yang-Mills (CYM) equation
have been considered. In this work, we have evaluated the equilibration
time from the chaotic behavior of CYM [1]. We have developed a...
Dr
Francesco Barile
(Universita degli Studi di Bari-Universita e INFN)
Experiments upgrade, future facilities and instrumentations
Poster
The ALICE experiment, dedicated to the study of heavy-ion collisions at LHC energies, features a high-quality particle identification system, based on the the Inner Tracking System (ITS), the Time-Projection-Chamber (TPC), the Time-of-Flight (TOF) and the HMPID. The ALICE-HMPID (High Momentum Particle Identification detector) has been designed to identify charged pions and kaons in the range...
Márton Nagy
(MTA KFKI RMKI, H-1525 Budapest 114, P.O.Box 49, Hungary)
Global and collective dynamics
Poster
Simple and exact solutions of relativistic hydrodynamics are
presented, including the first exact solution of relativistic
hydrodynamics with non-zero total angular momentum, an important
characteristics of mid-central and peripheral heavy ion collisions.
The consequences of these new solutions are explored in data
analysis. The effects of longitudinal work, acceleration and the
rotation...
Dr
Masakiyo Kitazawa
(Osaka University)
QCD at high temperature and density
Poster
The inverse of a Euclidean correlation function has an analytic
relation to the inverse of a corresponding retarded
propagator in real time.
We argue that this analyticy is exploited in the analysis of
real-time functions with Euclidean correlator obtained in
lattice QCD Monte Carlo simulations complementary to
the standard analysis of spectral functions.
We analyze the inverse of...
Cheuk-Yin Wong
(Oak Ridge National Laboratory)
New theoretical developments
Poster
In a nuclear collision at RHIC and LHC, a large number of particles
and antiparticles are produced. The production of matter and
antimatter particles in close space-time proximity raises the
interesting question whether chance encounters of some of the produced
charged particles and antiparticles may lead to the formation of
exotic matter-antimatter molecules as debris of the collision. ...
Sona Pochybova
(KFKI Research Institute for Particle and Nuclear Physics-Hungari)
Jets
Poster
We propose a set of jet-energy dependent cuts to be used to distinguish between quark and gluon jets experimentally based on a Monte-Carlo study of their properties. Using these cuts we are able to achieve up to 80% purity of our selection. Further, we introduce the possibility to calibrate these cuts via gamma-jet and multi-jet events, which represent clean production channels for quark and...
Dr
Tamar Friedmann
(University of Rochester)
New theoretical developments
Poster
It is well-known that making reliable predictions about low-energy QCD and hadrons is a great challenge, as perturbative methods of quantum field theory do not apply when the coupling constant is strong. The common approach has been to propose various dynamical models which are inspired by assumptions, ideas, and intuition borrowed from physical systems which are not QCD. In this talk, I...
Laure Marie Massacrier
(Institut de Physique Nucleaire de Lyon (IPNL)-Universite Claude)
Experiments upgrade, future facilities and instrumentations
Poster
ALICE is the experiment dedicated to the study of the quark gluon plasma in heavy-ion collisions at the LHC. Improvement of ALICE sub-detectors for the upgrade plans of the year 2017 are ongoing. The Muon Forward Tracker (MFT) is a proposal in view of this upgrade. The MFT is a Silicon pixels detector added in the Muon spectrometer acceptance (-4$<$eta$<$-2.5) upstream of the hadronic...
Arun Prakash
(BHU,Varanasi,India)
Experiments upgrade, future facilities and instrumentations
Poster
The compressed baryonic matter (CBM) experiment at the future FAIR accelerator center in Darmstadt, Germany, aims at the investigation of baryonic matter at highest net baryon densities but moderate temperatures, by colliding heavy-ions at beam energies from 10 to 45 A GeV. The research program comprises the exploration of basic landmarks of the QCD phase diagram like transitions from...
Adam Kisiel
(CERN)
Correlations and fluctuations
Poster
We report on the results of identical pion femtoscopy of the pp collisions at the LHC with the Bose-Einstein correlations. We present the final analysis of the ALICE pp datasets at sqrt{s}= 0.9 TeV and 7 TeV and the preliminary results for sqrt{s}=2.76 TeV.
Detailed pion femtoscopy studies in heavy-ion collisions have shown
that emission region sizes ("HBT radii") decrease with increasing...
Frank Michler
(University of Frankfurt)
Electromagnetic probes
Poster
Direct photons play an important role as electromagnetic probes from a
quark-gluon plasma (QGP) created in heavy-ion collisions. After being
once produced, they leave the medium undisturbed an thus provide direct insight into the early stage of the collision. We use the real time Keldysh formalism to investigate how non-equilibrium effects such as a finite lifetime modify the resulting...
Eduardo Fraga
(Universidade Federal do Rio de Janeiro)
QCD phase diagram
Poster
Given the short lifetime and the reduced volume of the quark-gluon plasma (QGP) formed in high-energy heavy ion collisions, a possible critical endpoint (CEP) will be blurred over a region and the effects from criticality severely smoothened. Nevertheless, the non-monotonic behavior of correlation functions near criticality for systems of different sizes, given by different centralities in...
Martin Schulc
(Faculty of Nuclear Sciences and Physical Engineering (FNSPE)-Cze)
Correlations and fluctuations
Poster
We investigate proton rapidity correlations for a fireball that fragments due to non-equilibrium effects at the phase transition from deconfined to hadronic phase. Such effects include spinodal fragmentation in case of first order phase transition at lower collision energies and cavitation due to sudden rise of the
bulk viscosity at the crossover probed at LHC and the RHIC. The study is...
Dr
Iurii Karpenko
(Bogolyubov Institute for Theoretical Physics)
Global and collective dynamics
Poster
The hydrokinetic approach [1,2] to A+A collisions describes hydrodynamic expansion of systems created in A+A collisions and their dynamic decoupling according to particle liberation probabilities in a way inspired by Boltzmann equation. The up-to-date version of hydro-kinetic model include the realistic features of heavy ion collisions typical for RHIC and LHC energies in the way directed by...
Dr
Richard Neufeld
(LANL)
New theoretical developments
Poster
I present a new derivation for the distribution of energy and momentum transmitted from a fast parton to a medium of thermalized quarks and gluons, or the source term. A thermal field theory approach enables the direct evaluation of the source term from the divergence of the QCD energy momentum tensor. This approach is more general than previously used Boltzmann transport techniques and...
Chang Beomsu
(ALICE)
Global and collective dynamics
Poster
Measurement of the azimuthal anisotropy of charged particles produced in heavy-ion collisions is one of the most powerful tools to study the properties of QCD Matter.
An analysis of charged hadron flow in Pb-Pb data taken by the ALICE experiment at $\sqrt{s_{NN}}$=2.76 TeV will be discussed. The event plane [1] was reconstructed using the VZERO detector (two scintillator arrays covering...
Barbara Betz
(Columbia University)
Jets
Poster
We use (3+1)-dimensional hydrodynamic simulations to describe
the propagation of a jet through an opaque medium and to investigate
the underlying jet-medium interactions. We discuss that the
double-peaked structure seen in the two-particle correlations
measured at the Relativistic Heavy Ion Collider (RHIC), suggested as a signal for the creation of a Mach cone, can arise due to the...
Dr
George Moschelli
(Frankfurt Institute for Advanced Studies)
Correlations and fluctuations
Poster
LHC and RHIC experiments exhibit a ridge-like enhancement of two particle correlations that is narrow in relative azimuthal angle $\Delta\phi$
and broad in relative pseudorapidity $\Delta\eta$. Causality implies that correlations between particles separated by a large $\Delta\eta$ must originate at the moment of production. These measurements can therefore reveal how particle production...
Zvi Citron
(Weizmann Institute of Science)
Pre-equilibrium and initial state physics
Poster
Deuteron-gold collisions offer insights into the nuclear structure function and a valuable baseline for Au+Au collisions. The d+Au system provides the opportunity to probe the gluonic structure of the Au nucleus. There are strong theoretical and experimental interests in the possibility of gluon saturation effects influencing parton distributions at very low x in the nucleon. This effect...
Michael Skoby
(Purdue University)
Correlations and fluctuations
Poster
Long-Range Forward-Backward multiplicity correlations(LRC) may be a signal for multiple partonic interactions in dense matter, whereas short-range correlations are due to independent sources [1,2]. Previously, strong LRC have been measured at STAR in 200 GeV central Au+Au collisions, and were shown to decrease with decreasing centrality [3]. The Color Glass Condensate model, which describes...
Jan Uphoff
(Goethe University Frankfurt)
Heavy flavor and quarkonia production
Poster
Heavy quark and J/psi production as well as their space-time evolution are studied in transport simulations of heavy-ion collisions at RHIC and LHC. In the partonic transport model Boltzmann Approach of MultiParton Scatterings (BAMPS) heavy quarks can be produced in initial hard parton scatterings or during the evolution of the quark-gluon plasma. Subsequently, they interact with the medium...
Prof.
Larisa Bravina
(Department of Physics-University of Oslo-Unknown)
Global and collective dynamics
Poster
Multiplicity, rapidity and transverse momentum distributions of hadrons produced in inelastic and non-diffractive pp - collisions at energies from 200 GeV to 14 TeV are described within Quark Gluon String Model. Good agreement with the available experimental data, including the LHC data at $\sqrt{s}$ = 7 TeV, is
obtained and predictions are made for the collisions at top LHC...
Hadron thermodynamics and chemistry
Plenary
Dr
Wei-Tian Deng
(Frankfurt Institute for Advanced Studies)
New theoretical developments
Poster
We updated the HIJING Monte Carlo model with the latest parton distribution functions and new set of the parameters in the two-component-model that controls total p+p cross section and the central pseudorapity density. We study hadron spectra and multiplicity distributions using the HIJING 2.0 model and compare to recent experimental data from p + p collisions at the LHC energies. Using a...
Dilan Madagodahettige Don
(University of Houston)
Hadron thermodynamics and chemistry
Poster
The Width and the mass of short lived resonances are sensitive to the medium properties during the phase transition from the deconfined partonic phase to the confined hadronic phase. Heavy hadrons have a larger probability to be produced within the quark gluon plasma phase due to their short formation times. Heavy mass, high momentum resonances from jet fragmentation are more likely to be...
Dr
Michael McCumber
(University of Colorado)
Correlations and fluctuations
Poster
Fluctuations in the initial conditions for relativistic heavy ion collisions are proving to be crucial to understanding final state flow and jet quenching observables. The initial geometry has been parameterized in terms of moments in the spatial anisotropy (i.e. e2, e3, e4, e5, …), and it has been stated in multiple published articles that the vector directions of odd moments are uncorrelated...
Dr
Sascha Vogel
(Subatech)
Heavy flavor and quarkonia production
Poster
One of the most promising probes to study deconfined matter created in high energy nuclear collisions at RHIC and LHC is the energy loss of (heavy) quarks. It has been shown in experiments at the Relativistic Heavy Ion Collider that even charm and bottom quarks, despite their high mass, experience a remarkable stopping in the Quark Gluon Plasma.
In this exploratory investigation we study...
Dr
Clément Gombeaud
(University of Bielefeld), Prof.
Nicolas Borghini
(University of Bielefeld)
Heavy flavor and quarkonia production
Poster
We consider the possibility that heavy quarkonia admit different bound states in a QGP, between which they can transition dynamically. We show that the vacuum mass eigenstates are not the relevant eigenstates for the in-medium dynamics. This leads in particular to abundance ratios of the various states which deviate from the predictions of static models. Additionally, the quarkonium dynamics...
Prof.
Masayuki Asakawa
(Osaka University)
Global and collective dynamics
Poster
We analyze hydrodynamic evolution of fireballs created by
relativistic heavy ion collisions by applying a high resolution
scheme of numerical hydrodynamics with a focus on the possibility
of shock formation in the course of time evolution.
The possibility of shock formation has not been taken into
account seriously in numerical analysis of relativistic heavy ion collisions. State of...
AMAL SARKAR
(iit-bombay)
Correlations and fluctuations
Poster
The Relativistic Heavy-Ion Collider (RHIC), at BNL, has started its beam energy scan program to locate the QCD critical point which is also one of the main aims of the STAR experiment.
Calculations on the lattice predict that the higher moments of the multiplicity distribution of the conserved quantities like the net-charge, net-baryon, net-strangeness are related to the corresponding...
Radoslaw Ryblewski
(Institute of Nuclear Physics PAN)
Pre-equilibrium and initial state physics
Poster
A new framework of highly-anisotropic hydrodynamics is introduced [1] that includes dissipation effects. Dissipation is defined by the form of the entropy source that depends on the pressure anisotropy and vanishes for the isotropic fluid. With a simple ansatz for the entropy source obeying general physical requirements, we are led to a non-linear equation describing the time evolution of the...
Markus Fasel
(Gesellschaft fuer Schwerionen forschung mbH (GSI))
Heavy flavor and quarkonia production
Poster
The measurement of the production of heavy-flavour hadrons in proton-proton collisions is a crucial test for perturbative QCD. Additionally it provides the reference for heavy-flavour studies in heavy-ion collisions. Thanks to its excellent electron identification capabilities the ALICE detector is well suited for the measurement of the open heavy-flavour cross section via single electrons. A...
Dr
Asis Chaudhuri
(Variable Energy Cyclotron Centre)
Global and collective dynamics
Poster
Ongoing heavy ion collision at Large Hadron Collider, CERN is expected to settle the important issues like the possibility of formation of the lattice QCD predicted strongly interacting nuclear matter known as Quark Gluon Plasma (QGP) and the important issue of thermalization and the time taken by the system to achieve the same. Recently ALICE collaboration [1] measured the centrality...
Christian Ivan
(GSI)
Global and collective dynamics
Poster
The anisotropic flow of identified particles is an important observable to test the collective behavior of the dense matter created in heavy-ion collisions.
We report on the methods used on the first measurements of elliptic and triangular flow for charged pions, kaons, protons, neutral kaons and $Lambda$ in lead-lead collisions at $sqrt(s_{NN})$=2.76 TeV measured with the ALICE detector at...
Sanshiro Mizuno
(Graduate School of Pure and Applied Sciences-University of Tsuku)
Global and collective dynamics
Poster
Particle species dependence of transverse momentum distribution as well as elliptic event anisotropy v2 have been beautifully described by hydrodynamic model calculation in terms of radial and elliptic collective expansion in high energy heavy ion collisions.
Initial participant position fluctuation is also suggested as a source of triangular initial geometry, which could then expand...
Dr
Sungtae Cho
(Yonsei University)
Hadron thermodynamics and chemistry
Poster
We propose a new approach of using relativistic heavy ion collisions to identify and study multi-quark hadrons. We focus on the expected production yields of these hadrons and show that their production yields are strongly affected by their internal structure [1], e.g. multi-quark configurations or hadronic molecules.
We mainly use the coalescence model, which was successful in...
Dr
Shusu Shi
(the STAR collaboration)
Global and collective dynamics
Poster
We present a systematic study of the transverse momentum ($p_T$), rapidity and centrality dependence of elliptic flow, $v_2$, using several methods in Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5 and 39 GeV. The difference between $v_2$ using event plane from detectors separated in rapidity ($v_2${2}) and four particle cumulants ($v_2${4}) seems to decrease as the beam energy decreases....
Sudipan De
(Variable Energy Cyclotron Centre (VECC)-Department of Atomic Ene)
Global and collective dynamics
Poster
We report the first measurement of the multiplicity and pseudorapidity distributions of photons in the pseudorapidity region of 2.3 < η < 3.9 in proton-proton collisions at center of mass energies of 0.9 TeV and 7 TeV at the LHC. The photon measurement is dominated by neutral pion decays and thus complimentary to those of the charged particles. Multiplicity distributions at both energies...
Prof.
Toshitaka Tatsumi
(Kyoto U.)
QCD phase diagram
Poster
Recently there have been many works about the inhomogeneous phases accompanying the chiral transition, which should have implications on relativistic heavy-ion collisions as well as compact-star phenomena [1].
Among them we here concentrate on the emergence and properties of a special one called dual-chiral-density wave (DCDW) state, which enjoys interesting features such as...
Dr
Volodymyr Magas
(University of Barcelona)
Global and collective dynamics
Poster
Substantial collective flow is observed in collisions between Lead nuclei at LHC as evidenced by the azimuthal correlations in the transverse momentum distributions of the produced particles [1].
We perform simulations of the Pb+Pb heavy ion collisions at LHC at 1.38 + 1.38 TeV/nucl within the three module model. Our calculations, in particular, show that the v1-flow, which was rather weak...
Prof.
Dinesh Srivastava
(Variable Energy Cyclotron Centre), Dr
Rupa Chatterjee
(University of Jyvaskyla)
Electromagnetic probes
Poster
We explore the intensity correlations for thermal photons having $K_T\leq$ 2 GeV/$c$, for central collisions of heavy nuclei at RHIC and LHC energies. These photons get competing contributions from the quark and the hadronic phases. This competition gives rise to a unique structure, especially in the outward correlation function, due to the interference between the photons from the two...
Chanaka De Silva
(University of Houston)
Jets
Poster
Two particle number correlations in relative azimuth and pseudo-rapidity ($\Delta \phi$, $\Delta \eta$) develop novel features in heavy ion collisions at 200 GeV when compared to p+p results at the same energy.
Earlier STAR results have shown a $\Delta \eta$ elongated structure for the small $\Delta \phi$ angles (on the same-side) and the development of significant deformations at $\Delta...
Barbara Trzeciak
(Warsaw University of Technology)
Heavy flavor and quarkonia production
Poster
Barbara Trzeciak for the STAR Collaboration
Currently there are many models with different assumptions regarding J/$\psi$ production mechanism that seem to describe the production cross section from experimental data reasonably well. Information on J/$\psi$ spin alignment, commonly named as J/$\psi$ polarization, may allow to discriminate J/$\psi$ production models. Moreover the prediction...
Dr
Ionut Cristian Arsene
(Gesellschaft fuer Schwerionen forschung mbH (GSI))
Heavy flavor and quarkonia production
Poster
The J/\psi production mechanism in proton-proton collisions is not fully understood and the measurement of the cross-section at LHC energies will bring new constraints on theoretical models.
The production of charm quarks takes place in the early collision stages. Therefore, in the case of heavy ions, they probe the hot and dense quark-gluon medium that is expected to be formed in the...
Bruno Alexandre Boyer
(Institut de Physique Nucleaire (IPN)-Universite de Paris-Sud (Pa)
Heavy flavor and quarkonia production
Poster
ALICE (A Large Ion Collider Experiment) is the LHC experiment dedicated to the study of the Quark Gluon Plasma (QGP) using heavy-ion collisions. Heavy quarkonium measurements in pp collisions are very important to constraint the different models available and as a reference for heavy ion collisions. Acceptance x efficiency corrections are a fundamental step of the analysis in order to extract...
Claudio Geuna
(IRFU-cea - Centre d'Etudes de Saclay)
Heavy flavor and quarkonia production
Poster
Claudio Geuna, CEA Saclay Irfu/SPhN
Gif-sur-Yvette, 25 March 2011
on behalf of the ALICE collaboration
Abstract
The ALICE experiment at LHC has collected, in March 2011, proton-proton data at sqrt(s) = 2.76 TeV. This energy in the center of mass allows to have a pp reference for the PbPb collisions that have been collected, at the end of 2010, at sqrt(sNN) = 2.76 TeV.
In this...
Christopher Coleman-Smith
(Duke Physics)
Jets
Poster
Recent results for Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$~TeV from
the LHC have shown dramatic di-jet asymmetry, implying a strong medium modification of jets as they pass through the QGP.
A fully-relativistic Monte-Carlo Boltzmann transport code, the Parton
Cascade Model (PCM), is used to simulate the development of a jet in a
partonic medium. The PCM includes collisional and...
Claude Andre Pruneau
(Wayne State University-Unknown-Unknown)
Jets
Poster
Measurements of inclusive jet production cross sections in proton-proton ($pp$) collisions provide a direct test of predictions of perturbative quantum chromodynamics. They also provide a baseline for measurements in heavy ion collisions. Jets are the collimated spray of particles originating from the fragmentation of hard scattered partons in the collision. They are defined by clustering...
Mriganka Mouli MONDAL
(Institute of Physics, Bhubaneswar)
Jets
Poster
The intrinsic transverse momentum of partons and the possible initial and final state gluon radiation associated with hard scatterings give rise to an acoplanarity of di-jets which depends on both the $Q^2$ of hard scatterings and the center of mass energy of the colliding beams. Multiple scatterings of the hard scattered partons in cold nuclear matter may also alter the measured...
Jan Kapitan
(Nuclear Physics Institute ASCR)
Jets
Poster
Full jet reconstruction in heavy-ion collisions is a promising tool for the quantitative study of properties of the dense medium produced in heavy-ion collisions at RHIC. Jet studies in d+Au collisions are important to disentangle initial state nuclear effects from medium-induced kT broadening and jet quenching.
We present inclusive jet pT spectra in d+Au collisions from the 2007-2008 RHIC...
Andras Gabor Agocs
(KFKI Research Institute for Particle and Nuclear Physics)
Jets
Poster
Jet matter interaction remains a central question and a theoretical challenge in heavy-ion physics and might become important in high-multiplicity events in
proton-proton collisions at LHC energies. Full jet measurements at LHC are hoped to reconstruct the complete energy loss process and fragmentation of the hard
parton in the medium. Since, jet reconstruction will be constrained to small...
Dr
Akihiro Nishiyama
(University of Tsukuba)
Pre-equilibrium and initial state physics
Poster
In this presentation, we propose the Kadanoff-Baym approach to the early nonequilibrium stage of ultrarelativistic heavy ion collisions and present recent results about equilibration of gluons. First we introduce the Kadanoff-Baym equation and present the proof of H-theorem for given off-shell dynamics of gluons. Next we show entropy production and equilibration with numerical analyses of this...
Achim Heinz
(ITP Frankfurt am Main)
QCD phase diagram
Poster
Effective hadronic models have been widely used to describe the chiral
phase transition. In this work we study the behavior of the critical
temperature T_c for the restoration of chiral symmetry as function of
the number N_c of colors. We find that T_c increases with Sqrt[N_c];
this scaling contradicts the basic expectations for the chiral phase
transition which, just as the...
Yasuhiro Kohno
(Osaka University)
QCD at high temperature and density
Poster
We attempt to constrain transport coefficients in second order viscous hydrodynamics by SU(3) lattice gauge simulation for the range of temperature 0.5 < T/T_c < 4. On the basis of the relaxation time approximation and Kubo formula, we relate a ratio of the shear viscosity to the relaxation time of the shear stress to fluctuations of off-diagonal components of energy-momentum tensor on the...
Prof.
Christina Markert
(University of Texas at Austin)
Electromagnetic probes
Poster
Hadronic resonances can play a pivotal role in providing experimental
evidence for partial chiral symmetry restoration in the deconfined
quark-gluon phase produced at RHIC and the LHC. Their lifetimes, which
are comparable to the lifetime of the fireball, make them
a valuable tool to study medium modifications to the resonant state
due to the chiral phase transition signatures of mass...
Gunnar Gräf
(Frankfurt Institute for Advanced Studies)
Correlations and fluctuations
Poster
We use the non-equilibrium transport approach Ultra-relativistic Quantum Molecular Dynamics (UrQMD) [1] to compute the dynamics of heavy ion collisions up to LHC energies. From this model we obtain directly the full phasespace distribution of all particles at the kinetic freeze out. By using the quantum reweighting technique on the freeze out distribution we extract the two-particle...
383.
Light meson production in d+Au collisions measured by PHENIX experiment at sqrt(s_NN) = 200 GeV
Dmitry Kotov
(PNPI RAS)
Hadron thermodynamics and chemistry
Poster
High pT particle suppression in heavy ion collisions appears to be one of the most exciting discoveries at RHIC. The suppression is explained by jet-quenching via partonic energy loss in a hot and dense matter created in such collisions. Nevertheless, theoretical models tuned to describe hadron suppression versus pT and centrality suffer from ambiguities in description of collision dynamics,...
Dr
Mohammed Mia
(Columbia University)
New theoretical developments
Poster
We study linear confinement of quarks in a class of large N gauge theories using gravity duals that capture the logarithmic runnings of the coupling constants in the IR and strongly coupled asymptotic conformal behavior in the UV. First we classify the most general dual gravity that describes linear confinement of quarks at zero temperature and then show that at higher temperatures, quarks...
Dr
Song Zhang
(Shanghai Institute of Applied Physics, CAS, China)
Correlations and fluctuations
Poster
The production of hypertriton and light nuclei are simulated in a dynamical coalescence model coupled with a multi-phase transport model (AMPT)~\cite{SZhang10}. The beam energy dependence of strangeness population factor, $S_{3}$ = $^{3}_{\Lambda}H/(^{3}He\times\frac{\Lambda}{p})$, is calculated to study local baryon-strangeness correlation as a valuable tool to probe the nature of the dense...
Hui Wang
(Michigan state university)
Correlations and fluctuations
Poster
STAR has recently reported charge-dependent azimuthal correlations that are sensitive to the charge separation effect in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV [1]. Qualitatively, these results agree with some of the theoretical predictions for local parity violation in heavy-ion collisions. However, a study using reaction-plane-dependent balance functions shows an alternative...
Grigori Feofilov
(St. Petersburg State University)
Correlations and fluctuations
Poster
Long-Range (Forward-Backward) Pt and Multiplicity Correlations
in pp Collisions at 0.9 and 7 TeV
The ALICE Collaboration
(Submitted by Grigory Feofilov)
Long-range rapidity and azimuthal correlations (LRC) of charged particles are a sensitive
tool to study the initial conditions for the Quark Gluon Plasma (QGP) formation [1],[2],[3].
Measured in separated pseudorapidity intervals,...
Dr
Yorito Yamaguchi
(University of Tokyo)
Electromagnetic probes
Poster
Direct photons in low pT region have been of great interest for a long time since thermal photons from Quark Gluon Plasma (QGP) are considered to contribute predominantly.
Attempts to measure low pT direct photons using EMCals could not succeed since a finite energy resolution of the EMCal prevents us from separating direct photon signal from a large amount of background of hadron decay...
Bingchu Huang
(STAR BNL)
Electromagnetic probes
Poster
Ultra-relativistic heavy ion collisions provide a unique environment to study the properties of strongly-coupled Quark Gluon Plasma (sQGP) at high temperature and high energy density. One of the crucial probes to study the sQGP is the di-electron production in the low ($M_{ll}$ $<$ $1.0 GeV/c^{2}$) and the intermediate ($1.0$ $<$ M_{ll}$ $<$ $3 GeV/c^{2}$) mass region. In the intermediate...
Yan Zhu
(University of Bielefeld)
Jets
Poster
Medium excitation by jet shower propagation inside a quark-gluon plasma is studied within a linear Boltzmann transport and a multiphase transport model. Contrary to the naive expectation, it is the deflection of both the jet shower and the Mach-cone-like excitation in an expanding medium that is found to give rise to a double-peak azimuthal particle distribution with respect to the initial jet...
Ioannis Bouras
(University of Frankfurt)
Global and collective dynamics
Poster
In a microscopic transport model we investigate evolution
of conical structures using different source terms. Development
of a strong collective behavior near the ideal hydro limit is visible,
resulting in formation of Mach Cones. In addition, for the first time
the transition from ideal to viscous Mach Cones is demonstrated.
We investigate dependence of the Mach Cone angle in different...
Benjamin Dönigus
(Research Division and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany & Helmholtz Research School H-QM, Frankfurt, Germany)
Hadron thermodynamics and chemistry
Poster
The measurement of short-lived resonances allows the investigation of the collision
dynamics and of the properties of the hot and dense medium created in high-energy
collisions. We study the production of the two hadronic resonances Δ++(1232) → pπ+
and Λ(1520) → pK− in pp collisions at √s = 7 TeV with the ALICE apparatus at the
LHC as a baseline for heavy-ion collisions. We present the...
Quan Wang
(Purdue University)
Global and collective dynamics
Poster
It has been suggested that local parity violation in QCD would lead to charge separation of quarks by the Chiral Magnetic Effect (CME) in heavy ion collisions.
Charge separation could yield a dynamical charge multiplicity asymmetry with respect to the reaction plane.
In this poster, we report results on charge multiplicity asymmetry
correlations in $\sqrt{s_{NN}}$ = 200 GeV Au+Au and d+Au...
Maxime Rene Joseph Guilbaud
(Institut de Physique Nucleaire de Lyon (IPNL)-Universite Claude)
Global and collective dynamics
Poster
ALICE (A Large Ion Collider Experiment) is the LHC experiment dedicated to the study of heavy-ion collisions. The aim of ALICE is to study the properties of a state of deconfined nuclear matter, the Quark Gluon Plasma (QGP), which lattice QCD predicts to be created at the extreme temperatures and energy densities accessible in such collisions.The VZERO detector, made of scintillator hodoscopes...
Dr
Shingo Sakai
(Lawrence Berkeley National Lab. (LBNL))
Heavy flavor and quarkonia production
Poster
High $p_{T}$ heavy flavor (charm and beauty) production is an important probe of partonic energy loss in hot QCD matter.
Measurement of the suppression of heavy flavor decay electrons production in nuclear collisions will reflect the energy loss of the parent heavy quarks.
We present the analysis strategy and first results for inclusive heavy flavor decay electrons production in...
Olga Driga
(Laboratoire de Physique Subatomique et des Technologies Associees, SUBATECH)
Jets
Poster
The measurement of the neutral meson transverse momentum (p_T) spectra in the new energy regime of the LHC is an important input to constrain theoretical models describing hadron production within the perturbative quantum chromodynamics. Such measurements are the first ones that have been performed by the ALICE electromagnetic calorimeter (EMCal) in proton-proton collisions at sqrt(s)=900 GeV,...
Collaboration CMS
(UCLouvain)
Global and collective dynamics
Poster
Collective flow is an important probe of the earliest stages in the expansion of the hot and dense matter created in relativistic heavy-ion collisions. Higher harmonics of the azimuthal distribution of emitted particles, in particular $v_3$ and $v_4$, complement $v_2$ measurements in elucidating the dynamical evolution of the bulk medium and providing constraints on its transport properties....
Soumya Mohapatra
(Department of Physics-State University of New York (SUNY))
Global and collective dynamics
Poster
Collective harmonic flow and jet-medium interactions are two phenomena under intense study in ultra-relativistic heavy ion collisions at RHIC and the LHC. One outstanding question is how to disentangle these two contributions for various single and multiple particle observables. Both higher-order harmonic flow ($v_1$, $v_2$, $v_3$, ...) and jet-medium interactions, for example, have been...
Dr
Ermes Braidot
(Lawrence Berkeley National Lab. (LBNL))
Pre-equilibrium and initial state physics
Poster
We present the measurement of inclusive differential $\pi^0$ yields in p+p and centrality-selected Pb+Pb collisions at $\sqrt{s_{NN}}=\mathrm{\,2.76 TeV}$, using the large-acceptance ALICE Electromagnetic Calorimeter (EMCal). The recently completed EMCal enhances ALICE capabilities for the study of jets, neutral mesons, electrons, and direct photons. The EMCal acceptance (110 degrees in...
Livio Bianchi
(Universita degli Studi di Torino-Universita & INFN, Torino-Unkno)
Heavy flavor and quarkonia production
Poster
The ALICE experiment at the LHC measures quarkonium and open heavy flavour production down to low transverse momentum (pt=0, for quarkonium) at forward rapidity in the muon channel. In this scope, the quarkonia and heavy flavour physics program in pp collisions aims to define a proper normalization for nuclear collision studies and to address prominent unresolved issues, such as the...
Hao Qiu
(Institute of Modern Physics)
Heavy flavor and quarkonia production
Poster
J/Ψ elliptic flow (v2) is sensitive to both the J/Ψ production mechanism and the elliptic flow of heavy quarks. While some models predict that J/Ψ produced through direct nucleon-nucleon process have very limited v2, J/Ψ produced by the recombination of c and cbar pairs could carry finite v2, depending on the interaction between charm quarks and the medium. Furthermore, due to their long...
Akihisa Takahara
(University of Tokyo)
Electromagnetic probes
Poster
The idea to use the strong electromagnetic fields present in high-energy nucleus
nucleus collisions to study photoproduction at hadron colliders has attracted
growing interest in recent years.
PHENIX measured J/\psi photo-production in ultra-peripheal (UPC) Au+Au collisions
at \sqrt{sNN} =200 GeV.
We define central UPC trigger as events with no activity in the Beam-Beam Counters,
but...
534.
Measurement of J/ψ → e+e− Production in Pb-Pb Collisions at √s = 2.76 TeV with ALICE at the LHC
Julian Book
(Institut fuer Kernphysik - Frankfurt)
Heavy flavor and quarkonia production
Poster
The investigation of the properties of strongly interacting matter under extreme conditions is the aim of the LHC heavy ion program. Quarkonia states such as the J/ψ will provide insights into the earliest and hottest stages of heavy ion collisons where the formation of a Quark-Gluon Plasma (QGP) is expected.
Measuring these bound states of heavy quarks via their dileptonic decay modes is one...
Christoph Baumann
(IKF, Goethe-Universität Frankfurt)
Electromagnetic probes
Poster
The ALICE experiment at the CERN-LHC is dedicated to study the properties of the Quark-Gluon Plasma created in ultrarelativistic heavy-ion collisions. Low-mass electron-positron pairs are
an excellent probe for all stages of the collision because they do not undergo strong final state interactions. With its unique tracking and particle identification capabilites extending to very low...
Alexander Borissov
(Wayne State University)
Electromagnetic probes
Poster
Measurement of neutral meson production from photon decays at ALICE experiment is performed by means of two electromagnetic calorimeters (EMCAL and PHOS) and/or conversion of photons in central tracking system. For two and more photon decaying mesons (pi^0, eta,omega)
a possibility of combined calorimetry and conversion measurement is explored. It allows an independent cross check of data...
Dr
Paraskevi Ganoti
(Oak Ridge National Laboratory)
Jets
Poster
The measured π0 production spectrum in p+p collisions at 7 TeV (2010 data), where both photons are reconstructed in the ALICE EMCal, will be presented. An accurate measurement of the π 0 production spectrum requires a thorough understanding of the response of the ALICE EMCal. The details of the analysis are
described, including comparisons with Monte Carlo simulations of the EMCal response,...
Matthieu Lenhardt
(Laboratoire de physique subatomique et des technologies associee)
Heavy flavor and quarkonia production
Poster
Recently, it has been argued that high-multiplicity pp collisions could lead to the formation of high energy density matter as in heavy ions collisions [1]. Indeed, the charged particle multiplicity reached in pp collisions at the LHC [2] is similar to the one measured in semi-peripheral Cu-Cu collisions at \sqrt{s_{NN}} = 200 GeV [3].
We will present the dependence on charged particle...
Frederick Kramer
(IKF, Goethe-Universität Frankfurt)
Heavy flavor and quarkonia production
Poster
ALICE is the dedicated heavy-ion physics experiment at the Large Hadron Collider (LHC). It is designed to provide excellent capabilities to study the Quark-Gluon Plasma (QGP), the deconfined state of strongly-interacting matter, in the highest energy density regime opened up by the LHC. Quarkonia, bound states of heavy (charm or bottom) quarks such as the J/ψ, are crucial probes of the QGP....
Dr
Yvonne Pachmayer
(Ruprecht-Karls-Universitaet Heidelberg-Unknown-Unknown)
Heavy flavor and quarkonia production
Poster
In high-energy nucleus-nucleus collisions, heavy flavour quarks, i. e. charm and bottom, are produced on a very short time scale in the initial hard scattering processes and thus they experience the whole history of the collision. Therefore, they are valuable probes to address the features of the interaction of hard partons with the hot and dense state of matter, that is expected to be formed...
Shawn Whitaker
(Iowa State University)
Heavy flavor and quarkonia production
Poster
Measuring states in the charmonium and bottomonium families is predicted to provide an indication of the temperature of the quark gluon plasma. In a hot medium less tightly bound states are predicted to be dissociated at lower temperatures than the more tightly bound ground states.
Understanding quarkonium suppression mechanisms of the QGP is one of the outstanding challenges for theorists...
Martin Rybar
(Faculty of Mathematics and Physics-Charles University-Unknown)
Jets
Poster
The LHC has opened a new kinematic regime for the jet measurements in heavy ion collisions. With the factor of 14 increase in collision energy compared to RHIC data, new insights have already been achieved. The observation of centrality-dependent di-jet asymmetry measured by ATLAS and CMS is strongly suggestive of jet quenching -- strong energy loss of parton traversing a hot and dense QCD...
Xin Li
(STAR Collaboration)
Heavy flavor and quarkonia production
Poster
The dependence of parton energy loss on the space-time evolution of the QCD
medium is believed to be mostly responsible for the azimuthal angular
anisotropy distribution of high transverse momentum (pT) particles in
nucleus-nucleus collisions. Simultaneous measurements of both the nuclear
modification factors and the elliptic flow parameter v2 can provide insights
on parton energy loss...
Dr
Michael Tannenbaum
(Brookhaven National Laboratory (BNL)-Unknown-Unknown)
Jets
Poster
The method of measuring $\hat{x}_h$, the ratio of $\hat{p}_{Ta}$, the away-parton $p_T$, to $\hat{p}_{Tt}$, the trigger-parton $p_T$, using two-particle correlations at RHIC, which is sensitive to the away parton energy loss due to the surface bias, will be reviewed. This measurement is simply related to the new variable introduced at LHC for the di-jet transverse momentum imbalance,...
Prabhat Pujahari
(IIT Bombay)
Global and collective dynamics
Poster
In non-central nucleus-necleus collisions, the azimuthal angle of the outgoing particles are cor-related with the direction of the impact parameter and this phenomenon is known as anisotropic flow which is sensitive to the system properties evolved early in the collisions and hence provides evidence for the formation of a hot and dense medium created in such collisions. The measurement of...
Lizhu Chen
(CCNU/BNL)
QCD phase diagram
Poster
One of the main goals of the RHIC Beam Energy Scan program is to search for the QCD critical point (CP) in the QCD phase diagram. Non-monotonic dependence of the ratios of the various moments of conserved (such as net-charge and net-baryon) number distributions with beam energy has been considered to be a signal for the CP. In addition to this, it has been recently proposed that a certain set...
Irakli Garishvili
(Lawrence Livermore National Laboboratory)
Global and collective dynamics
Poster
Precisely determining the essential properties of QGP, such as the ratio of shear viscosity to entropy density, eta/s, initial temperature, T_{init}, and energy density remains among the greatest challenges in the field of heavy ion physics.
To constrain these properties we have developed a software framework CHIMERA that is designed to perform statistical evaluation of multiple QGP...
Prof.
Pengfei Zhuang
(Tsinghua University),
Yunpeng Liu
(Tsinghua University)
Heavy flavor and quarkonia production
Poster
The momentum dependence of quarkonium dissociation temperature in hot medium is investigated and is applied to the quarkonium suppression in high energy nuclear collisions. For a fast moving quarkonium, the screening is significantly weaken, its dissociation temperature becomes higher and leads to a transverse momentum broadening in heavy ion collisions at RHIC and LHC.
Dr
Edward Sarkisyan-Grinbaum
(CERN)
Global and collective dynamics
Poster
The energy-dependence of charged particle mean multiplicity and pseudorapidity density at midrapidity measured in nucleus-nucleus and (anti)proton-proton collisions are studied in the entire available energy range. The study is performed using a
model, which considers the multiparticle production process according to the dissipating energy of the participants and their types, namely a...
Prof.
Shi-Yuan Li
(SDU)
Pre-equilibrium and initial state physics
Poster
The universe is expanding, hence in early times it was more dense than it is today. The spacetime curvature becomes arbitrarily large around the singular point, leaving room for arbitrarily large energetic processes as well as arbitrarily dense matter states to take place. The matter states of the largest densities that human being can produce and study microscopically in laboratory are
those...
Eva Sicking
(Universität Münster / CERN)
Correlations and fluctuations
Poster
A Large Ion Collider Experiment (ALICE) is the experiment at the Large Hadron Collider (LHC) optimized for heavy-ion collisions. However, ALICE is also studying pp collisions which not only provides important reference measurements but is also part of a stand-alone pp physics program. In particular, high multiplicity pp collisions are an interesting field of study of particle production...
Dr
Gabor David
(Brookhaven National Laboratory)
Jets
Poster
Despite rapidly improving experimental precision,
theory sophistication and the large variety of available data a coherent
description of the properties of the hot, dense medium produced in
relativistic heavy ion collisions remain so far elusive. Using SPS, RHIC
and LHC heavy ion nuclear modification and flow data we will look at the
evolution (system size and collision energy) as well...
Daniel Lohner
(Ruprecht-Karls-Universitaet Heidelberg)
Jets
Poster
The neutral pion yield is measured with ALICE by reconstructing photons
via their conversion into e+e- pairs. Transverse momentum spectra are
presented for pp and PbPb collisions as well as the resulting nuclear
modification factor R_AA. The pi0 yield is studied as a function of the
emission angle w.r.t. the reaction plane. At high transverse momentum
this provides insights into the...
Experiments upgrade, future facilities and instrumentations
SPS, FAIR, low energy RHIC, NICA/MPD (experiments and theory)
Prof.
Kyoichiro Ozawa
(KEK)
Experiments upgrade, future facilities and instrumentations
Poster
The origin of the hadron mass has been drawing strong interests in nuclear and particle physics. Especially in QCD, mass of hadrons is composed of a sum of the effective mass of valence quarks, known as constituent quark mass, and their interaction term. According to theoretical models, the effective mass of valence quarks is determined by chiral property of QCD vacuum. This mechanism is...
Dr
Wei Li
(Shanghai Institute of Applied Physics)
Heavy flavor and quarkonia production
Poster
RHIC measurement on non-photonic electrons from heavy quark decays shows similar suppression as light hadrons at high $p_{T}$ in central Au+Au collisions. However, the interpretation is complicated by the combined contributions from charm and bottom decays. Non-photonic electron and charged hadron azimuthal correlation has been used as a powerful tool to disentangle charm and bottom...
Dr
Gergely Barnafoldi
(KFKI Research Institute for Particle and Nuclear Physics of the HAS)
New theoretical developments
Poster
Non-extensive thermodynamics is a novel and promising tool for the statistical interpretation of high energy phenomena. In particular the experimental systems are far from the familiar canonical state. On the basis of generalized entropy and energy composition rules also Tsallis--Pareto-like distributions can be obtained. Such distributions reproduce extremely well the various transverse...
Karoly Uermoessy
(Dept. for Theor. Phys., ELTE; Research Institute for Particle and Nuclear Physics (KFKI))
Jets
Poster
The first part of this talk presents a possible statistical physical description of hadron production in electron-positron collisions. The main idea of the model is that hadrons produced inside a jet may be considered as a microcanonical ensemble, with multiplicity fluctuating event by event. The obtained hadron spectrum is in good agreement with measured fragmentation functions...
Marlene Nahrgang
(Goethe-University Frankfurt and Frankfurt Institute for Advanced Studies (FIAS))
QCD phase diagram
Poster
We present a dynamic study of nonequilibrium fluctuations and correlations at the chiral phase transition starting from the linear sigma model with constituent quarks.
Within the formalism of the two-particle irreducible (2PI) effective action the nonequilibrium dynamics of the sigma field coupled to the fluid dynamic expansion of quarks is obtained consistently. We derive the Langevin...
Dr
Naoto Tanji
(High Energy Accelerator Research Organization, KEK)
Pre-equilibrium and initial state physics
Poster
Nonperturbative particle production via the Schwinger mechanism has been studied as a mechanism of matter formation in the context of heavy-ion collisions. In the color flux model, the generation of longitudinal color-electric fields between two Lorentz-contracted nuclei receding from each other has been assumed. These electric fields polarize the vacuum and produce quarks and gluons. Also in...
Lusaka Bhattacharya
(Saha Institute of Nuclear Physics)
Electromagnetic probes
Poster
We calculate the nuclear modification factor ($R_{AA}$) of light
hadrons by taking into account the initial state momentum
anisotropy of the quark gluon plasma (QGP) expected to be formed in
relativistic heavy ion collisions.
Such an anisotropy can result from the
initial rapid longitudinal expansion of the matter.
A phenomenological model for the space time evolution of...
Dr
Umme Jamil
(SINP, Kolkata, India)
Heavy flavor and quarkonia production
Poster
The charm quarks are expected to be produced at the
initial fusion of the ultrarelativistic
heavy-ion collisions. Just after the production, they will propagate
through the Quark Gluon Plasma (QGP) and will loose energy by
colliding with quarks and gluons and radiating gluons.
We calculate the nuclear modification
factor $R_{AA}$ of charm
quarks, produced from the initial...
Jan Cepila
(Faculty of Nuclear Sciences and Physical Engineering (FNSPE)-Czech Technical University in Prague)
Pre-equilibrium and initial state physics
Poster
We discuss a common feature of all known reactions on nuclear targets - a significant suppression at large Feynman xF and large transverse momenta pT of produced particles. The main emphasis is devoted to production of prompt photons since they are not expected to be accompanied by any final state interaction, either energy loss or absorption. Therefore, besides the Cronin enhancement at...
Bikash Sinha
(Variable Energy Cyclotron Centre)
Heavy flavor and quarkonia production
Poster
The drag and diffusion coefficients of heavy quarks propagating through a
baryon rich quark gluon plasma have been calculated. The nuclear suppression
factor, $R_{AA}$ for non-photonic single electron spectra resulting
from the semileptonic decays of heavy flavour mesons have been evaluated.
The role of non-zero baryonic chemical potential on $R_{AA}$ has been
highlighted.
Dr
Jean-Christophe CAILLON
(CENBG)
New theoretical developments
Poster
We have built the nucleon by taking into account explicitly both confinement like in an MIT bag model and a dynamic generation of the quark masses in a Nambu Jona Lasinio model.
Therefore, we have supposed a QCD vacuum modified in a cavity and thus a modified quark condensate coming from the presence of three valence quarks in this cavity. Quarks acquire their masses through their...
Dr
Margaret Markova
(Institute for System Dynamics and Control Theory)
QCD at high temperature and density
Poster
Two ways of deriving the fluctuation-dissipation theorem (FDT) for soft fermion excitations in a hot non-Abelian plasma being in a thermal equilibrium are discussed. The first of them is based on the extended (pseudo)classical model in describing a quark-gluon suggested by us, while the second one rests on the standard technique of calculation of the FDT for thermodynamically equilibrium...
Experiments upgrade, future facilities and instrumentations
Rolf scharenberg
(Purdue University)
QCD at high temperature and density
Poster
The Color String Percolation Model (CSPM)[1] is used to determine the equation of state (EOS) of the Quark-Gluon Plasma (QGP) produced in central Au-Au collisions at $\sqrt{s_{NN}}$ = 200 A GeV using STAR data at RHIC.When the initial density of interacting colored strings exceeds the 2D percolation threshold a cluster is formed, which defines the onset of color deconfinement. These...
Yosuke Watanabe
(Tokyo University)
Electromagnetic probes
Poster
The PHENIX experiment observed a large enhancement of electron-positron
pairs in the invariant mass range of 0.2 to 0.5 GeV/c^2 in Au+Au collisions
at sqrt(s_NN)=200 GeV. However, it is difficult to draw a firm physics
conclusion from the measurement, since the measurement still has large
statistical and systematic uncertainties.The main uncertainty comes from
the small...
Collaboration CMS
(UCLouvain)
Experiments upgrade, future facilities and instrumentations
Poster
The two CMS Zero Degree Calorimeters have been designed to measure and trigger on photons and neutrons produced in pp and heavy ion collisions. Their trigger rate is proportional to the luminosity and can be used as a measure of beam quality. Augmented by scintillators they can also give a measure of the luminous region and its growth during the store. By measuring the horizontal distribution...
Dr
Martino Gagliardi
(Sezione INFN di Torino, Torino, Italy)
Heavy flavor and quarkonia production
Poster
J/psi production is one of the key measurements in heavy-ion collisions at the LHC. It is expected to provide means to discriminate between different scenarii, ranging from full suppression by colour screening to enhancement by charm quark pair recombination.
In 2010, the LHC delivered Pb-Pb collisions at the center of mass energy per nucleon pair of 2.76 TeV. The knowledge of the J/psi...
Bikash Sinha
(Variable Energy Cyclotron Centre)
Electromagnetic probes
Poster
Photons and dileptons are important probe for the lattice QCD predicted deconfined matter, commonly called Quark-Gluon-Plasma (QGP). Unlike the strongly interacting hadrons, which can give information about the ‘last scattering surface’, electromagnetically interacting photons and dileptons give information about the matter at the deep interior. Viscous effects on photon and dilepton...
Kyrre Skjerdal
(University of Bergen-Unknown-Unknown)
Global and collective dynamics
Poster
The strong electromagnetic fields present in ultra-peripheral Pb+Pb collisions at the CERN LHC accelerator lead to large cross sections for particle production in photonuclear interactions[1]. It will be shown that photonuclear processes may constitute a significant background to peripheral and semi-central hadronic nuclear collisions.
The cross sections for photonuclear interactions...