# QM 2011 - XXII International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

22-28 May 2011
Centre Bonlieu
Europe/Zurich timezone
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Displaying 553 contributions out of 553
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 via ... More
Presented by David TLUSTY
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Experiments upgrade, future facilities and instrumentations
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 dete ... More
Presented by Mickey CHIU
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Experiments upgrade, future facilities and instrumentations
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 Bjor ... More
Presented by Mr. Sanjib MUHURI, Mr. Martijn REICHER, Mr. Tomoya TSUJI
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Experiments upgrade, future facilities and instrumentations
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 well a ... More
Presented by Dr. Aihong TANG
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
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 present ... More
Presented by Yaxian MAO on 24 May 2011 at 16:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 Tevatro ... More
Presented by Hermes LEON VARGAS
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
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 properties ... More
Presented by Stefania VELICA
Type: Parallel Session: Pre-equilibrium and initial state
Track: Pre-equilibrium and initial state physics
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 will pr ... More
Presented by Dr. Paloma QUIROGA ARIAS on 26 May 2011 at 16:40
Type: Parallel Session: Future facilities and experiment upgrades
Track: Experiments upgrade, future facilities and instrumentations
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 that so ... More
Presented by Prof. Thomas PEITZMANN on 26 May 2011 at 16:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 high-en ... More
Presented by Xianbao YUAN
Type: Plenary Session: Global collective dynamics
Track: Global and collective dynamics
Presented by Jiangyong JIA on 24 May 2011 at 11:25
Type: Plenary Session: Hard probes II: true jets
Track: Jets
Presented by Brian COLE on 25 May 2011 at 12:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
Soft Collinear Effective Theory (SCET) is a powerful tool to study jet physics. In order to describe jet propagation in the dense QCD matter created in ultra-relativistic nuclear collisions, SCET needs to be modified by the inclusion of the transverse to the jet axis gluon mode, which is commonly referred to as a Glauber gluon. We construct the Lagrangian of the resulting effective theory and ... More
Presented by grigory OVANESYAN
Type: Plenary Session: Global collective dynamics
Track: Global and collective dynamics
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 invest ... More
Presented by Raimond SNELLINGS on 24 May 2011 at 11:45
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
Ante Bilandzic for the ALICE collaboration Measurements of anisotropic flow provided evidence for the creation of strongly interacting matter which appears to behave as an almost ideal fluid. Anisotropic flow signals the presence of multiple interactions and is very sensitive to the initial spatial anisotropy of the overlap region in non-central heavy-ion collisions. In this talk we report meas ... More
Presented by Ante BILANDZIC on 23 May 2011 at 15:20
Type: Parallel Session: Jets
Track: Jets
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 this ... More
Presented by Peter LEVAI on 27 May 2011 at 16:20
Type: Plenary Session: Heavy flavor and Quarkonia in medium
Track: Heavy flavor and quarkonia production
Presented by David MATEOS on 27 May 2011 at 08:30
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
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 emissio ... More
Presented by Dmitry BLAU
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 the detectio ... More
Presented by Nicolas ARBOR
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 lon ... More
Presented by Collaboration CMS
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 exp ... More
Presented by Jon-Ivar SKULLERUD
Type: Parallel Session: Heavy flavor
Track: Heavy flavor and quarkonia production
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 resolution, ... More
Presented by Zhen HU on 23 May 2011 at 19:10
Type: Plenary Session: Pre equilibrium and initial stage and global collective dynamics
Track: Pre-equilibrium and initial state physics
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. The fr ... More
Presented by Dr. Alberica TOIA on 24 May 2011 at 08:55
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
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 equi ... More
Presented by Kevin DUSLING
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
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 par ... More
Presented by Juan TORRES-RINCON
Type: Parallel Session: Electromagnetic probes
Track: Electromagnetic probes
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 relativistic dissipative ... More
Presented by Dr. Yukinao AKAMATSU on 27 May 2011 at 19:10
Type: Parallel Session: Jets
Track: Jets
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 and in ... More
Presented by Bronislav ZAKHAROV on 27 May 2011 at 18:50
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Electromagnetic probes
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 energie ... More
Presented by Sreekanth V.
Type: Parallel Session: Jets
Track: Jets
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 to e ... More
Presented by Andre YOON on 26 May 2011 at 16:20
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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, th ... More
Presented by Antoine LARDEUX
Type: Poster Track: Global and collective dynamics
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 thermalized ... More
Presented by Prof. Joerg AICHELIN
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 for ... More
Presented by Rosi REED
Type: Poster Track: Global and collective dynamics
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 of $... More Presented by Dr. Asis CHAUDHURI, Dr. Bikash SINHA Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes 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 primaril ... More Presented by Jason KAMIN on 27 May 2011 at 18:10 Type: Poster Track: Heavy flavor and quarkonia production 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 radiative a ... More Presented by santosh K DAS Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 fluctuations ... More Presented by Satyajit JENA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 production me ... More Presented by Sören SCHLICHTING Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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. The ... More Presented by Dr. Panos CHRISTAKOGLOU on 27 May 2011 at 15:40 Type: Parallel Session: QCD Phase diagram Track: QCD phase diagram 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 flavors ... More Presented by Dr. Vladimir SKOKOV on 24 May 2011 at 16:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 through th ... More Presented by Prithwish (for the STAR collaboration) TRIBEDY Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 fit ... More Presented by Dr. Ludmila MALININA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry 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 stu ... More Presented by Shikshit GUPTA Type: Poster Track: Global and collective dynamics 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 obtai ... More Presented by Dr. Asis CHAUDHURI Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 the in ... More Presented by Victoria ZHUKOVA on 23 May 2011 at 17:50 Type: Parallel Session: Jets Track: Jets 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 collision ... More Presented by Jacek OTWINOWSKI on 26 May 2011 at 15:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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}$for a given centrality emerges by averaging over different path lengths as the overlap zone of two colliding nuclei has typically a nearly elliptical shape in the transverse plane. The partons traversing the medium in the in ... More Presented by Dr. Dong Jo KIM Type: Poster The TPC is the main tracking detector in the central barrel ($|\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$<1GeV/c, pions, kaons, and protons, can be cleanly separated in different momentum intervals. At high momentum,$p$... More Presented by Peter CHRISTIANSEN Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets The TPC is the main tracking detector in the central barrel ($|\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$<1GeV/c, pions, kaons, and protons, can be cleanly separated in different momentum intervals. At high momentum,$p$... More Presented by Dr. Peter CHRISTIANSEN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry 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 collisio ... More Presented by Georg WOLSCHIN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Presented by Christian Holm CHRISTENSEN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 non- ... More Presented by Anton ALKIN Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 collisio ... More Presented by Constantinos LOIZIDES on 23 May 2011 at 15:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 charge ... More Presented by Michael Linus KNICHEL Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production 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 SPS ... More Presented by Dr. Pietro CORTESE on 27 May 2011 at 16:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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$. The UrQMD approach includes explicit interactions of the charmed particles with the surrounding medium. Different ... More Presented by Thomas LANG Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production Charmonia in medium provide us information on the change of the confinement property induced by the medium. We have developed an approach based on QCD sum rule which connects temperature dependent QCD condensates to the spectral function through the operator product expansion of the current correlation function. The leading contribution to the OPE is the dimension four gluon condensate ... More Presented by Dr. Kenji MORITA Type: Parallel Session: Heavy flavors Track: Heavy flavor and quarkonia production CMS is fully equipped to measure hard probes in the di-muon decay channel in the high multiplicity environment of nucleus-nucleus collisions. Such probes are especially relevant for studying the quark gluon plasma since they are produced at early times and propagate through the medium, mapping its evolution. In particular, the$J\psi$production in heavy ion collisions has been studied at differen ... More Presented by Torsten DAHMS on 24 May 2011 at 15:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 with ... More Presented by Prof. Alexeii KUREPIN Type: Parallel Session: Heavy flavors Track: Heavy flavor and quarkonia production 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 relat ... More Presented by Prof. Chiho NONAKA on 24 May 2011 at 16:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 becomi ... More Presented by Rashid KHAN Type: Parallel Session: Theory developments Track: New theoretical developments 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 collisions, an ... More Presented by Prof. Dmitri KHARZEEV on 23 May 2011 at 15:00 Session: Closing on 28 May 2011 at 11:50 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 presented (a ... More Presented by Matthew WYSOCKI Type: Parallel Session: Pre-equilibrium and initial state Track: Pre-equilibrium and initial state physics RHIC experiments have observed that inclusive hadron yields in the forward rapidity (deuteron) direction for$\sqrt{s_{NN}} = 200$GeV d+Au collisions are suppressed relative to p+p collisions. The mechanism for the suppression has not been firmly established; theoretical descriptions include nuclear shadowing, initial-state parton energy loss, and gluon saturation. We present measurements by ... More Presented by Dr. Mickey CHIU on 26 May 2011 at 15:40 Type: Plenary Session: Global collective dynamics Track: Global and collective dynamics Recent collective flow measurements including higher moment event anisotropy from the PHENIX experiment will be presented, the particle type, beam energy dependence and the relation with jet modification will be discussed. Presented by Shinichi ESUMI on 24 May 2011 at 10:45 Type: Parallel Session: Energy scan Track: Global and collective dynamics A central goal in experimental nuclear physics is to map out the QCD phase diagram, and to measure precisely the properties of the different phases. In order to achieve this goal, RHIC has embarked on an energy scan program involving gold nuclei at various energies. The data collected by the PHENIX experiment for this program consists of data sets obtained at$\sqrt{s_{NN}}$= 200, 62, 39 and 7.7 ... More Presented by Xiaoyang GONG on 27 May 2011 at 17:50 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 the be ... More Presented by Ryohji AKIMOTO Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Heavy flavor and quarkonia production Presented by Dmitri KHARZEEV on 27 May 2011 at 11:10 Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Heavy flavor and quarkonia production Presented by Dima KHARZEEV on 27 May 2011 at 09:50 Type: Plenary Session: Pre equilibrium and initial stage and global collective dynamics Track: Global and collective dynamics Presented by Bernd MUELLER on 24 May 2011 at 09:35 Type: Plenary Session: Global collective dynamics Track: Global and collective dynamics Presented by Ulrich HEINZ on 24 May 2011 at 12:10 Type: Plenary Session: Hard probes II: true jets Track: Jets Presented by Peter JACOBS on 25 May 2011 at 12:25 Type: Plenary Session: Hard probes I: hadron spectra Track: Jets Presented by Miklos GYULASSY on 25 May 2011 at 10:00 Type: Plenary Session: Correlations & fluctuations Presented by Prof. Krzysztof REDLICH on 26 May 2011 at 10:00 Type: Plenary Session: Correlations & fluctuations Presented by Volker KOCH on 26 May 2011 at 12:15 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 sili ... More Presented by Dr. MAKI KUROSAWA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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$puzzle. We try to constrain these cold nuclear matter (CNM) effects by fitting the EPS09 parametrization plus a break-up cross sec ... More Presented by Darren MCGLINCHEY Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations A silicon vertex tracker (VTX) is one of the upgrade programs in the PHENIX experiment to measure the production of heavy (charm and bottom) quarks in Au+Au and polarized p+p collisions. The production of heavy quarks is a powerful tool to study both the properties of a dense partonic matter created in high energy heavy ion collisions and the gluon contribution to the spin structure of proto ... More Presented by Dr. Takashi HACHIYA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram We present results for QCD in the strong coupling limit, obtained from a worm-type algorithm on a discrete spatial lattice but with continuous Euclidean time. This is obtained by sending both the anisotropy parameter$\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$has to be carried out. ... More Presented by Dr. Wolfgang UNGER Session: Flash talks Presented by Wolfgang UNGER on 27 May 2011 at 12:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Large number of semi-hard partons deposit their energy and momentum in nuclear collisions at the LHC. Hereby they can induce collectively moving streams within the hydrodynamically behaving bulk matter. Although the production of hard partons is isotropic, in non-central collisions we have an anisotropy of their spatial distribution. We argue that via the interaction of the produced streams the sp ... More Presented by Dr. Boris TOMASIK Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets The study of transverse momentum distributions of charged particles in pp collisions at the LHC provides information about both soft and hard contributions to particle production. Charged particle transverse momentum distributions in pp collisions at 0.9, 2.76 and 7 TeV have been measured at mid-rapidity (|eta|$<$0.8) by ALICE. We present the energy dependence of the inclusive average transverse ... More Presented by Philipp LUETTIG Type: Plenary Session: Correlations & fluctuations Track: Correlations and fluctuations Presented by Swagato MUKHERJEE on 26 May 2011 at 08:30 Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 with ... More Presented by Dr. Claudia RATTI on 23 May 2011 at 18:50 Type: Plenary Session: Correlations & fluctuations Track: Correlations and fluctuations Measurements of charged dihadron angular correlations are presented in proton-proton (pp) and Lean-Lead (PbPb) collisions, over a broad range of pseudorapidity and azimuthal angle, using the CMS detector at the LHC. In very high multiplicity pp events at center-of-mass energy of 7 TeV, a striking "ridge"-like structure emerges in the two-dimensional correlation function for particle pairs wit ... More Presented by Wei LI on 26 May 2011 at 11:15 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 Coulo ... More Presented by Dr. Oana RISTEA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 sizes ... More Presented by Prof. Yuanfang WU Type: Parallel Session: Future facilities and experiment upgrades Track: Experiments upgrade, future facilities and instrumentations 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 LHC e ... More Presented by Dr. Ken OYAMA on 26 May 2011 at 17:00 Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production 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$\sqrt{s_{NN}} = 2.76~{\rm TeV}$... More Presented by Dr. Andrea ROSSI on 27 May 2011 at 15:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 √s ... More Presented by Dr. Grelli ALESSANDRO Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 com ... More Presented by Zaida CONESA DEL VALLE Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 LHC ... More Presented by Giacomo ORTONA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 matter a ... More Presented by Dr. Bala RENU Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 azimutha ... More Presented by Chiara BIANCHIN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 matte ... More Presented by Alexey STAVINSKIY Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 review ... More Presented by Collaboration CMS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density 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 electrowe ... More Presented by Dr. Topi KAHARA Type: Parallel Session: QCD Phase diagram Track: QCD phase diagram I will discuss new lattice results on the deconfinement and chiral aspects of the transition in QCD at nonzero temperature. I will report on calculations performed using the Highly Improved Staggered Quark (HISQ) action on Nt=6, 8 and 12 lattices. I will show the continuum extrapolation for several quantities that are discussed in connection with the transition at nonzero temperature as well ... More Presented by Dr. Peter PETRECZKY on 24 May 2011 at 15:20 Type: Poster Track: Global and collective dynamics 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 equa ... More Presented by Prof. Teiji KUNIHIRO Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 deconfinement r ... More Presented by Dr. Song SHU Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 fro ... More Presented by Gyulnara EYYUBOVA Type: Parallel Session: Theory developments Track: New theoretical developments 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 relaxation ... More Presented by Prof. Dirk RISCHKE on 27 May 2011 at 15:40 Type: Parallel Session: Correlations and fluctuations Track: Pre-equilibrium and initial state physics 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 particular, ... More Presented by Dr. Jean-Yves OLLITRAULT on 23 May 2011 at 16:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 low-ma ... More Presented by Dr. Tariq MAHMOUD Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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. Institute fo ... More Presented by Alexeii KUREPIN Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 Hadron Bl ... More Presented by Ermias T. ATOMSSA Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes Dilepton distributions have been proposed as one of the penetrating probes for hot and dense nuclear matter created in high-energy nuclear collisions. Due to their relatively small final-state interaction cross-sections with the hot/dense environment, dileptons bring us direct information of the created matter in such collision. Since dileptons are created over all stages of heavy ion reactions, t ... More Presented by Jie ZHAO on 26 May 2011 at 15:40 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 time-of-f ... More Presented by Patrick HUCK Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics (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 simula ... More Presented by Dr. Martin POGHOSYAN on 23 May 2011 at 16:40 Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 correl ... More Presented by Jeremy Louis CALLNER on 24 May 2011 at 15:20 Type: Parallel Session: Jets Track: Jets 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 of di ... More Presented by Yetkin YILMAZ on 27 May 2011 at 17:30 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 and t ... More Presented by payal MOHNATY Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 covari ... More Presented by Dr. Olena LINNYK Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 by th ... More Presented by Prof. Bikash SINHA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 radia ... More Presented by Dr. Elvira SANTINI Session: Flash talks Presented by Elvira SANTINI on 27 May 2011 at 11:50 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 Sta ... More Presented by Dr. Bjørn BäUCHLE Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 using ... More Presented by Dennis PEREPELITSA Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes 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 NLO p ... More Presented by Dr. Edouard KISTENEV on 26 May 2011 at 16:40 Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes 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$can be a QGP s ... More Presented by Prof. Fuming LIU on 27 May 2011 at 18:50 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Fluctuations in the initial geometry of a nucleus-nucleus collision have been recently shown to produce the correlation structures known as ridge" and shoulder". These event-by-event fluctuations result in new types of anisotropic flow, such as triangular flow$v_3$and a new type of directed flow$v_1$, which, unlike the usual directed flow, is also present at midrapidity. The anisotrop ... More Presented by Dr. Fernando GARDIM Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics For the first time, the generation of the directed flow of particles emitted from the fireball created in heavy-ion collisions at RHIC is described using a 3+1D hydrodynamical model. The initial fireball density is constructed as a sum of contributions from forward and backward going participants. This asymmetry in the emission from the individual participants leads to a tilt of the source. Our ... More Presented by Iwona WYSKIEL-PIEKARSKA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Measurements of anisotropic flow in heavy-ion collisions provide insight into the early stage of the system's evolution. Directed flow,$v_1$, is imparted especially early. A change of sign in the slope of$dv_1/dy$for identified particles, particularly for protons, has been suggested as a possible signal of a first-order phase transition. In this talk, we present the STAR measurements of ... More Presented by Yadav PANDIT Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics We present a method to improve the description of 0+1 dimensional boost invariant dissipative dynamics in the presence of large momentum-space anisotropies. Instead of using the canonical hydrodynamical expansion of the distribution function around an isotropic equilibrium state, we expand around a state which is anisotropic in momentum space and parameterize this state in terms of three proper- ... More Presented by Dr. Mauricio MARTINEZ GUERRERO Type: Poster Track: Electromagnetic probes The effects of the shear and the bulk viscosities on the transverse momentum distribution of thermal photons have been studied. The effects of viscosity have been taken into account both in the phase space distributions of the particles taking part in the production process as well as in the space time evolution. We argue that the thermal photons can be ... More Presented by payal MOHNATY Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Novel set of second-order dissipative hydrodynamic equations for shear stress tensor of each component of a multi-component mixture is derived using the entropy principle [1]. Summation over the equations for all components leads to an effective relaxation-type one-component equation for the total system. In this equation the effective shear viscosity (or alternatively the$\eta/s$ratio) of t ... More Presented by Andrej EL Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations The experiment by the ultrarelativistic heavy ion collisions has opened a novel insight into the extreme state of matter. Besides, it provides an opportunity to study the dynamics of strong Abelian and non-Abelian gauge fields. In peripheral collisions, an extremely strong Abelian magnetic field is created by two colliding heavy ions having large electric charges. The magnetic field has a much gre ... More Presented by Dr. Koichi HATTORI Type: Poster Track: Heavy flavor and quarkonia production We evaluate the drag and diffusion coefficients of a hot hadronic medium consisting of pions, nucleons, kaons and eta using open charm mesons as a probe. The interaction of the probe with the hadronic matter has been treated in the framework of effective field theory. It is observed that the magnitude of both the transport coefficients are significant, indicating substantial amount of interact ... More Presented by Santosh K DAS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram The linear sigma model with quarks at very low temperatures provides an effective description for the thermodynamics of the strong interaction in cold and dense matter, being especially useful at densities found in compact stars and protoneutron star matter. Using the MSbar one-loop effective potential, we compute quantities that are relevant in the process of nucleation of droplets of quark matte ... More Presented by Leticia PALHARES Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations Terence J Tarnowsky (for the STAR Collaboration) Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. Results from new measurements of dynamical$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 measurement ... More Presented by Terence TARNOWSKY on 23 May 2011 at 16:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 periodic b ... More Presented by Vitalii OZVENCHUK Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 is ... More Presented by Alessandro BUZZATTI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 RG to ... More Presented by Dr. Yuki MINAMI Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 eccen ... More Presented by Dr. Yoshitaka HATTA on 23 May 2011 at 15:40 Type: Poster Track: Electromagnetic probes 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$) as function of momentum and temperature while calculating the drag ... More Presented by Lusaka BHATTACHARYA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production Measuring$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 the a ... More Presented by Collaboration CMS Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 resonance d ... More Presented by Bin ZHANG, Guo-Liang MA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics 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 sho ... More Presented by Bin ZHANG Type: Parallel Session: Theory developments Track: Electromagnetic probes 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 two ... More Presented by Dr. Olaf KACZMAREK on 27 May 2011 at 16:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 generate ... More Presented by Dr. Maxim CHERNODUB Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 reconstruction ... More Presented by Collaboration CMS Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 'leading' ... More Presented by Dr. Volodymyr KONCHAKOVSKI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 detecto ... More Presented by Dr. Michael K. MITROVSKI Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 measurement ... More Presented by Sangyong JEON on 27 May 2011 at 17:30 Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 deta ... More Presented by Mikolaj KRZEWICKI on 23 May 2011 at 18:10 Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 azi ... More Presented by Alexandru Florin DOBRIN on 27 May 2011 at 17:50 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 [2] a ... More Presented by Dr. KeJun WU Type: Poster Track: Jets 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$) produced in these collisions via the Bjorken formula (Bjorken, 1983 ... More Presented by Oeystein DJUVSLAND Type: Parallel Session: Energy scan Track: Jets The suppression of inclusive pion production by up to a factor of 5, which was first observed in Au + Au at √sNN= 130 GeV/c (e.g. [1]) and later in Au + Au at √sNN= 200 GeV/c [2, 3], is one of the most significant manifestations of the opaque QGP produced in heavy ion collisions. The absence of this suppression in d + Au collisions at the same energy indicates the final state nature of the sup ... More Presented by Norbert NOVITZKY on 27 May 2011 at 18:50 Type: Parallel Session: Energy scan Track: Correlations and fluctuations Non-central heavy ion collisions at RHIC create an anisotropic participant zone of QCD matter under extreme conditions of energy and matter density. While this zone is initially out-of-plane-extended, pressure gradients cause the hot, dense medium to expand preferentially in plane. Over time, this expansion makes the shape more spherical, perhaps even becoming extended in the in-plane direction. ... More Presented by Christopher ANSON on 27 May 2011 at 18:30 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics Previous RHIC results have shown that high-$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 colli ... More Presented by Ondrej CHVALA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 arise during ... More Presented by Saumia PANDIAT Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes 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 observables by ... More Presented by Rupa CHATTERJEE on 26 May 2011 at 16:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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, part ... More Presented by Yuji SAKAI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 abo ... More Presented by Dr. Mate CSANAD Type: Poster Track: Heavy flavor and quarkonia production 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. nic ... More Presented by Dr. binoy PATRA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 equation ... More Presented by Somnath DE, Prof. Dinesh SRIVASTAVA, Dr. Rupa CHATTERJEE Type: Parallel Session: Theory developments Track: New theoretical developments 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 minimal vo ... More Presented by Berndt MUELLER on 23 May 2011 at 15:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 metho ... More Presented by Prof. Akira OHNISHI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 1< p ... More Presented by Dr. Francesco BARILE Type: Parallel Session: Global and collective dynamics Track: QCD phase diagram 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}}=$7.7, 11.5 and 39 GeV. The second harmonic ($v_2$) ... More Presented by Dr. Alexander SCHMAH on 23 May 2011 at 18:50 Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics We develop a framework for event-by-event ideal hydrodynamics to study the differential elliptic flow which is measured at different centralities in Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). Fluctuating initial energy density profiles, which here are the event-by-event analogues of the eWN profiles, are created using a Monte Carlo Glauber model. Using the same event plane method ... More Presented by Hannu HOLOPAINEN on 27 May 2011 at 15:20 Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations Non-statistical event-by-event fluctuations of the mean transverse momentum of charged particles in pp and Pb--Pb collisions are studied using the ALICE experiment at the LHC. The analysis is performed at$|\eta| < 0.8$and$0.15 < p_{T} < 2 $~GeV/c. Multiplicity dependent results are obtained for pp collisions at$\sqrt{s}$~=~0.9, 2.76 and 7~TeV. Pb--Pb collisions at$\sqrt{s_{NN}}$~=~2.76~TeV ar ... More Presented by Stefan HECKEL on 24 May 2011 at 16:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 of ... More Presented by Márton NAGY Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density 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 quark ... More Presented by Dr. Masakiyo KITAZAWA Type: Poster Track: New theoretical developments 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. The ... More Presented by Cheuk-Yin WONG Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 gluon ... More Presented by Sona POCHYBOVA Track: Electromagnetic probes Photons and dileptons Track: Hadron thermodynamics and chemistry Hadrochemistry Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes 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 cha ... More Presented by Andrej KUGLER on 27 May 2011 at 18:30 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: New theoretical developments 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 present r ... More Presented by Dr. Tamar FRIEDMANN Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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$is generated, with mass ordering of the various particle species. Presented by Prof. Nicolas BORGHINI, Dr. Clément GOMBEAUD on 27 May 2011 at 18:30 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations ALICE is the experiment dedicated to the study of the quark gluon plasma in heavy-ion collisions at the LHC. Improvement of ALICE sub-detectors for the upgrade plans of the year 2017 are ongoing. The Muon Forward Tracker (MFT) is a proposal in view of this upgrade. The MFT is a Silicon pixels detector added in the Muon spectrometer acceptance (-4$<$eta$<$-2.5) upstream of the hadronic absorber. Th ... More Presented by Laure Marie MASSACRIER Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations The compressed baryonic matter (CBM) experiment at the future FAIR accelerator center in Darmstadt, Germany, aims at the investigation of baryonic matter at highest net baryon densities but moderate temperatures, by colliding heavy-ions at beam energies from 10 to 45 A GeV. The research program comprises the exploration of basic landmarks of the QCD phase diagram like transitions from hadronic to ... More Presented by Arun PRAKASH We report on the results of femtoscopic analysis of Pb-Pb collisions at$\sqrt{s_{NN}}=2.76$~TeV with identical pions and pp collisions at$\sqrt{s}=0.9$,$2.76$and$7$~TeV with identical pions and kaons. Detailed femtoscopy studies in heavy-ion collisions at SPS and RHIC have shown that emission region sizes ("HBT radii") decrease with increasing pair momentum, which is understood as a manifes ... More Presented by Adam KISIEL on 24 May 2011 at 09:15 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 pair ... More Presented by Adam KISIEL Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 of t ... More Presented by Prof. Sergei VOLOSHIN on 24 May 2011 at 17:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 photon sp ... More Presented by Frank MICHLER Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 heavy i ... More Presented by Eduardo FRAGA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 performed ... More Presented by Martin SCHULC Session: Flash talks Presented by Mihee JO on 27 May 2011 at 12:30 Session: Flash talks Presented by Rosi REED on 27 May 2011 at 11:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 the p ... More Presented by Dr. Iurii KARPENKO Type: Poster Session: Poster Session 1 + Wine and Cheese Track: New theoretical developments 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 allows ... More Presented by Dr. Richard NEUFELD Type: Plenary Session: Global collective dynamics Presented by Björn SCHENKE on 24 May 2011 at 10:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 pseudora ... More Presented by Chang BEOMSU Type: Plenary Session: Global collective dynamics Track: Global and collective dynamics 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 the ... More Presented by Julia VELKOVSKA on 24 May 2011 at 11:05 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 averagi ... More Presented by Barbara BETZ Type: Parallel Session: Theory developments Track: New theoretical developments 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 horizon. T ... More Presented by Derek TEANEY on 27 May 2011 at 16:00 Type: Plenary Session: Correlations & fluctuations Presented by Matthew LUZUM on 26 May 2011 at 10:50 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 occurs. ... More Presented by Dr. George MOSCHELLI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics 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 would ... More Presented by Zvi CITRON Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 sour ... More Presented by Michael SKOBY Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 via bi ... More Presented by Jan UPHOFF Type: Poster Track: Global and collective dynamics 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 energy$\sqrt{s}$= ... More Presented by Prof. Larisa BRAVINA Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Hadron thermodynamics and chemistry Type: Poster Session: Poster Session 1 + Wine and Cheese Track: New theoretical developments 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 strong g ... More Presented by Dr. Wei-Tian DENG Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry 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 affected ... More Presented by Dilan MADAGODAHETTIGE DON Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 the ... More Presented by Dr. Sascha VOGEL Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 w ... More Presented by Dr. Michael MCCUMBER Type: Parallel Session: Future facilities and experiment upgrades Track: Experiments upgrade, future facilities and instrumentations 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 centre-of ... More Presented by Prof. Alexander SORIN on 26 May 2011 at 15:40 Type: Parallel Session: Heavy flavor Track: Heavy flavor and quarkonia production 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 det ... More Presented by Dr. Heng-Tong DING on 23 May 2011 at 18:50 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 diffe ... More Presented by Prof. Nicolas BORGHINI, Dr. Clément GOMBEAUD Type: Parallel Session: Heavy flavors Track: Heavy flavor and quarkonia production 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 med ... More Presented by Abhisek SEN on 24 May 2011 at 16:00 Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production 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 setu ... More Presented by Dr. Marco MONTENO on 27 May 2011 at 16:40 Type: Parallel Session: Heavy flavor Track: Heavy flavor and quarkonia production 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 behaviou ... More Presented by Dr. Silvia MASCIOCCHI on 23 May 2011 at 18:30 Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Heavy flavor and quarkonia production 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, in-m ... More Presented by Andrea DAINESE on 27 May 2011 at 09:25 Session: Student lectures Presented by Francois GELIS on 22 May 2011 at 09:00 Session: Student lectures Presented by Roberta ARNALDI on 22 May 2011 at 11:40 Presented by Agnes MOCSY on 22 May 2011 at 14:45 Type: Poster Track: Global and collective dynamics 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 art hi ... More Presented by Prof. Masayuki ASAKAWA Type: Parallel Session: Hadron thermodynamics and chemistry Track: Jets 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 and K ... More Presented by Simone SCHUCHMANN on 23 May 2011 at 18:10 Type: Parallel Session: Jets Track: Jets 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 spectrum of ... More Presented by Barbara BETZ on 27 May 2011 at 15:40 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 susceptibil ... More Presented by AMAL SARKAR Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics 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 anis ... More Presented by Radoslaw RYBLEWSKI Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 firs ... More Presented by Markus FASEL Type: Poster Track: Global and collective dynamics 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 dependence o ... More Presented by Dr. Asis CHAUDHURI Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 the ... More Presented by Prof. Yuriy SINYUKOV on 23 May 2011 at 18:30 Type: Parallel Session: Energy scan Track: Hadron thermodynamics and chemistry 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 of ... More Presented by Dr. lokesh KUMAR on 27 May 2011 at 17:30 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 the L ... More Presented by Christian IVAN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 collectively ... More Presented by Sanshiro MIZUNO Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 calculat ... More Presented by Denes MOLNAR on 27 May 2011 at 18:50 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry 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 explaining th ... More Presented by Dr. Sungtae CHO Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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. The i ... More Presented by Dr. Shusu SHI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 follow d ... More Presented by Sudipan DE Type: Parallel Session: Pre-equilibrium and initial state Track: Correlations and fluctuations 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 fluctuating ... More Presented by Frederique GRASSI on 26 May 2011 at 16:20 Type: Poster Track: QCD phase diagram 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 parity-violating p ... More Presented by Prof. Toshitaka TATSUMI Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 parameter ... More Presented by Philippe MOTA on 23 May 2011 at 16:40 Type: Plenary Session: Pre equilibrium and initial stage and global collective dynamics Track: Pre-equilibrium and initial state physics Presented by Javier LOPEZ ALBACETE on 24 May 2011 at 08:30 Presented by David D'ENTERRIA on 22 May 2011 at 14:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 at R ... More Presented by Dr. Volodymyr MAGAS Type: Parallel Session: Pre-equilibrium and initial state Track: Pre-equilibrium and initial state physics 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 expansion phas ... More Presented by Hannah PETERSEN on 26 May 2011 at 16:00 Type: Parallel Session: Theory developments Track: New theoretical developments 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 QCD me ... More Presented by Dr. Jorge CASALDERREY SOLANA on 23 May 2011 at 15:40 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes We explore the intensity correlations for thermal photons having$K_T\leq$2 GeV/$c$, for central collisions of heavy nuclei at RHIC and LHC energies. These photons get competing contributions from the quark and the hadronic phases. This competition gives rise to a unique structure, especially in the outward correlation function, due to the interference between the photons from the two sources. Th ... More Presented by Prof. Dinesh SRIVASTAVA, Dr. Rupa CHATTERJEE Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets Two particle number correlations in relative azimuth and pseudo-rapidity ($\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 \phi ... More
Presented by Chanaka DE SILVA
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 that ... More
Presented by Barbara TRZECIAK
Type: Parallel Session: Heavy flavors
Track: Heavy flavor and quarkonia production
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 different pr ... More
Presented by Zebo TANG on 24 May 2011 at 15:40
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 poste ... More
Presented by Claudio GEUNA
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 collision. ... More
Presented by Dr. Ionut Cristian ARSENE
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 the ... More
Presented by Bruno Alexandre BOYER
Type: Parallel Session: Heavy flavors
Track: Heavy flavor and quarkonia production
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. At f ... More
Presented by Dr. Philippe PILLOT on 24 May 2011 at 17:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 radiative ... More
Presented by Christopher COLEMAN-SMITH
Type: Parallel Session: Jets
Track: Jets
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 par ... More
Presented by Dr. José Guilherme MILHANO on 24 May 2011 at 15:40
Type: Parallel Session: Jets
Track: Jets
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 collisi ... More
Presented by Dr. Christian KLEIN-BOESING on 24 May 2011 at 16:20
Type: Plenary Session: Hard probes II: true jets
Track: Jets
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 tracker. An ... More
Presented by Dr. Christof ROLAND on 25 May 2011 at 11:35
Type: Parallel Session: Theory developments
Track: Jets
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 the ... More
Presented by Dr. Abhijit MAJUMDER on 27 May 2011 at 16:40
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 algorit ... More
Presented by Claude Andre PRUNEAU
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 acoplanarity w ... More
Presented by Mriganka Mouli MONDAL
Type: Parallel Session: Jets
Track: Jets
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 on t ... More
Presented by Oliver FOCHLER on 27 May 2011 at 15:20
Type: Parallel Session: Jets
Track: Jets
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 loss ... More
Presented by Thorsten RENK on 24 May 2011 at 16:40
Type: Parallel Session: Jets
Track: Jets
In the particle-flow approach one attempts to combine information from all available sub-detector systems to reconstruct all stable particles. Such an event reconstruction has been shown to improve the resolution of jets and missing transverse energy in pp collisions compared to purely calorimetric measurements. This is achieved primarily by combining the precise momentum determination of charged ... More
Presented by Matthew NGUYEN on 27 May 2011 at 15:00
Type: Parallel Session: Jets
Track: Jets
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 constitu ... More
Presented by Guang-You QIN on 27 May 2011 at 17:50
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 run. W ... More
Presented by Jan KAPITAN
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
The ALICE detector carries out comprehensive measurements of high energy nucleus-nucleus collisions. Jet reconstruction in ALICE is enabled by combining charged particle measurements in the central tracking system, and neutral particle measurements in the Electromagnetic Calorimeter (EMCal). In this poster, we will show the jet yield enhancement using the EMCal high-tower (HT) trigger, compared t ... More
Presented by Rongrong MA
Type: Parallel Session: Jets
Track: Jets
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 signal-to-background r ... More
Presented by Alice OHLSON on 27 May 2011 at 18:10
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 cone ... More
Presented by Andras Gabor AGOCS
Type: Parallel Session: Theory developments
Track: New theoretical developments
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 medium ... More
Presented by Dr. Yacine MEHTAR-TANI on 23 May 2011 at 16:00
Session: Student lectures
Presented by Marco VAN LEEUWEN on 22 May 2011 at 11:00
Presented by Konrad TYWONIUK on 22 May 2011 at 14:30
Type: Parallel Session: Jets
Track: Jets
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 radial ... More
Presented by Dr. Guo-Liang MA on 27 May 2011 at 16:40
Type: Parallel Session: Hadron thermodynamics and chemistry
Track: Global and collective dynamics
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 momentum ar ... More
Presented by Iouri BELIKOV on 23 May 2011 at 17:30
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
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 describi ... More
Presented by Prof. Thomas HUMANIC on 23 May 2011 at 18:10
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Pre-equilibrium and initial state physics
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 equ ... More
Presented by Dr. Akihiro NISHIYAMA
Type: Plenary Session: Overviews
Presented by Steve MYERS on 23 May 2011 at 08:30
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
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 correlation fu ... More
Presented by Gunnar GRäF
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD phase diagram
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 deconfinemen ... More
Presented by Achim HEINZ
Type: Parallel Session: QCD Phase diagram
Track: QCD phase diagram
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 hydrodynamic mo ... More
Presented by Dr. Pasi HUOVINEN on 24 May 2011 at 16:20
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD at high temperature and density
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 lattice ... More
Presented by Yasuhiro KOHNO
Type: Parallel Session: Jets
Track: Jets
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 signi ... More
Presented by Kolja KAUDER on 27 May 2011 at 16:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Electromagnetic probes
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 shifts ... More
Presented by Prof. Christina MARKERT
Type: Parallel Session: Electromagnetic probes
Track: Electromagnetic probes
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 yields, ... More
Presented by Dr. Rikard SANDSTRöM on 26 May 2011 at 15:20
Type: Poster Session: Poster Session 1 + Wine and Cheese
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, parto ... More
Presented by Dmitry KOTOV
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: New theoretical developments
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 must de ... More
Presented by Dr. Mohammed MIA
Session: Flash talks
Presented by Hui WANG on 27 May 2011 at 12:00
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
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 origin of ... More
Presented by Hui WANG
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
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 matte ... More
Presented by Dr. Song ZHANG
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
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, these ... More
Presented by Grigori FEOFILOV
Type: Parallel Session: Electromagnetic probes
Track: Electromagnetic probes
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 the ... More
Presented by Dr. Antonio URAS on 27 May 2011 at 17:50
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Electromagnetic probes
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 photons, ... More
Presented by Dr. Yorito YAMAGUCHI
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Electromagnetic probes
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 mass re ... More Presented by Bingchu HUANG Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 multiplic ... More Presented by Matthieu LENHARDT Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 dir ... More Presented by Yan ZHU Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 scena ... More Presented by Ioannis BOURAS Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production 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 approxima ... More Presented by Mr. Hao MA on 27 May 2011 at 15:20 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Hadron thermodynamics and chemistry 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$TeV will be presented. They will be compared to results obtained at 900 GeV ... More Presented by Marek CHOJNACKI on 23 May 2011 at 15:40 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry The measurement of short-lived resonances allows the investigation of the collision dynamics and of the properties of the hot and dense medium created in high-energy collisions. We study the production of the two hadronic resonances Δ++(1232) → pπ+ and Λ(1520) → pK− in pp collisions at √s = 7 TeV with the ALICE apparatus at the LHC as a baseline for heavy-ion collisions. We present ... More Presented by Benjamin DöNIGUS Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics It has been suggested that local parity violation in QCD would lead to charge separation of quarks by the Chiral Magnetic Effect (CME) in heavy ion collisions. Charge separation could yield a dynamical charge multiplicity asymmetry with respect to the reaction plane. In this poster, we report results on charge multiplicity asymmetry correlations in$\sqrt{s_{NN}}$= 200 GeV Au+Au and d+Au colli ... More Presented by Quan WANG Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 determination ... More Presented by Livio BIANCHI Type: Parallel Session: Heavy flavors Track: Heavy flavor and quarkonia production 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 experim ... More Presented by Dr. Roberta ARNALDI on 24 May 2011 at 15:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 relax ... More Presented by Hao QIU Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 activi ... More Presented by Akihisa TAKAHARA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 of ... More Presented by Julian BOOK Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 momenta, AL ... More Presented by Christoph BAUMANN Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 and ex ... More Presented by Shawn WHITAKER Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 pseudorapidi ... More Presented by Yujiao CHEN on 23 May 2011 at 16:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 on ... More Presented by M. Maxime Rene Joseph GUILBAUD Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production High$p_{T}$heavy flavor (charm and beauty) production is an important probe of partonic energy loss in hot QCD matter. Measurement of the suppression of heavy flavor decay electrons production in nuclear collisions will reflect the energy loss of the parent heavy quarks. We present the analysis strategy and first results for inclusive heavy flavor decay electrons production in proton-proton ... More Presented by Dr. Shingo SAKAI Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics The measurement of the elliptic flow for charged particles in Pb+Pb collisions at sqrt(s_NN)=2.76 TeV with the ATLAS detector will be presented in a wide range of pseudorapidity, transverse momentum and collision centrality. The elliptic flow is measured by correlating azimuthal angles of reconstructed particle tracks with the event plane angle obtained from forward calorimeters. A large pseudorap ... More Presented by Adam TRZUPEK on 27 May 2011 at 15:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets The measurement of the neutral meson transverse momentum (p_T) spectra in the new energy regime of the LHC is an important input to constrain theoretical models describing hadron production within the perturbative quantum chromodynamics. Such measurements are the first ones that have been performed by the ALICE electromagnetic calorimeter (EMCal) in proton-proton collisions at sqrt(s)=900 GeV, 2.7 ... More Presented by Olga DRIGA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Collective flow is an important probe of the earliest stages in the expansion of the hot and dense matter created in relativistic heavy-ion collisions. Higher harmonics of the azimuthal distribution of emitted particles, in particular$v_3$and$v_4$, complement$v_2$measurements in elucidating the dynamical evolution of the bulk medium and providing constraints on its transport properties. With ... More Presented by Collaboration CMS Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Collective harmonic flow and jet-medium interactions are two phenomena under intense study in ultra-relativistic heavy ion collisions at RHIC and the LHC. One outstanding question is how to disentangle these two contributions for various single and multiple particle observables. Both higher-order harmonic flow ($v_1$,$v_2$,$v_3$, ...) and jet-medium interactions, for example, have been argued to ... More Presented by Soumya MOHAPATRA Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes In studies of the dense medium produced in ultra-relativistic heavy ion collisions, photons are important hard probes, since they are not expected to be modified by the medium. The measurement of isolated prompt photon production in PbPb collisions provides a test of perturbative quantum chromodynamics (pQCD) and the information to constrain the nuclear parton distribution functions. CMS has shown ... More Presented by Yong KIM on 27 May 2011 at 17:30 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics We present the measurement of inclusive differential$\pi^0$yields in p+p and centrality-selected Pb+Pb collisions at$\sqrt{s_{NN}}=\mathrm{\,2.76 TeV}$, using the large-acceptance ALICE Electromagnetic Calorimeter (EMCal). The recently completed EMCal enhances ALICE capabilities for the study of jets, neutral mesons, electrons, and direct photons. The EMCal acceptance (110 degrees in azimuth,$ ... More
Presented by Dr. Ermes BRAIDOT
Type: Parallel Session: Hadron thermodynamics and chemistry
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 as al ... More
Presented by Dr. Deepali SHARMA on 23 May 2011 at 18:50
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Electromagnetic probes
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 and ... More
Presented by Alexander BORISSOV
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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, in ... More
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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. Befor ... More
Presented by Frederick KRAMER
Session: Flash talks
Presented by Yvonne Chiara PACHMAYER on 27 May 2011 at 11:30
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 in ... More
Presented by Dr. Yvonne PACHMAYER
Type: Parallel Session: Global and collective dynamics
Track: Global and collective dynamics
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 taking ... More
Presented by Dr. Chiara OPPEDISANO on 27 May 2011 at 19:10
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
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 features o ... More
Presented by Sandra PADULA on 23 May 2011 at 17:50
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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 matter ... More
Presented by Martin RYBAR
Type: Parallel Session: Jets
Track: Jets
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 meas ... More
Presented by Aaron Richard ANGERAMI on 24 May 2011 at 15:20
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 mechan ... More
Presented by Xin LI
Type: Parallel Session: Jets
Track: Jets
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 wit ... More
Presented by Alexander MILOV on 26 May 2011 at 15:20
Type: Parallel Session: Electromagnetic probes
Track: Electromagnetic probes
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 expe ... More
Presented by Mihael MAKEK on 26 May 2011 at 16:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
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, $A_J=(\hat{p} ... More Presented by Dr. Michael TANNENBAUM Type: Parallel Session: Jets Track: Jets The propagation of hard partons through the strongly interacting matter created in high energy heavy-ion collisions involves widely separated scales. The methods of Effective Field Theories (EFT) can provide a factorized description at lowest nontrivial order, and a formalism where the correction to this factorization are calculable systematically order by order in the small ratios between the dif ... More Presented by Mr. Francesco D'ERAMO on 27 May 2011 at 19:10 Type: Parallel Session: Jets Track: Jets 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 elastic ... More Presented by Dr. Andrea BERAUDO on 26 May 2011 at 17:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 elliptic ... More Presented by Prabhat PUJAHARI Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 properti ... More Presented by Dr. Ilya SELYUZHENKOV on 27 May 2011 at 16:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 of ... More Presented by Lizhu CHEN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 signature ... More Presented by Irakli GARISHVILI Type: Parallel Session: QCD Phase diagram Track: Correlations and fluctuations 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 sixth ... More Presented by Frithjof KARSCH on 24 May 2011 at 15:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets Jet quenching parameter is an important quantity in order to understand energy losses in heavy ion collisions and to get insights into properties of deconfined quark-gluon plasmas. Soft Collinear Effective theory provides framework to define momentum broadening of probing quark/gluon and thus define jet quenching parameter as the expectation value of two space-like separated light-like Wilson line ... More Presented by Mindaugas LEKAVECKAS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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. Presented by Yunpeng LIU, Prof. Pengfei ZHUANG Type: Plenary Session: Hard probes II: true jets Track: Jets Presented by Korinna ZAPP on 25 May 2011 at 10:50 Type: Parallel Session: Jets Track: Jets 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 QCD ... More Presented by Mr. Jussi AUVINEN on 27 May 2011 at 18:30 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Hadron thermodynamics and chemistry 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 at l ... More Presented by D.D. CHINELLATO on 23 May 2011 at 17:50 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 combination ... More Presented by Dr. Edward SARKISYAN-GRINBAUM Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics 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 gen ... More Presented by Prof. Shi-Yuan LI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations 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 mechanisms ... More Presented by Eva SICKING Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 as ... More Presented by Dr. Gabor DAVID Type: Plenary Session: Correlations & fluctuations Presented by Marek GAZDZICKI on 26 May 2011 at 09:20 Type: Parallel Session: Energy scan Track: QCD phase diagram 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 baryon f ... More Presented by Marlene NAHRGANG on 27 May 2011 at 19:10 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 path-leng ... More Presented by Daniel LOHNER Session: New challenges Track: Experiments upgrade, future facilities and instrumentations SPS, FAIR, low energy RHIC, NICA/MPD (experiments and theory) Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 understoo ... More Presented by Prof. Kyoichiro OZAWA Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 transition ... More Presented by Tim SCHUSTER on 24 May 2011 at 16:40 Type: Parallel Session: Jets Track: Jets 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 ... More Presented by Dr. Ivan VITEV on 24 May 2011 at 16:00 Type: Parallel Session: Theory developments Track: New theoretical developments 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 (NLO ... More Presented by Giovanni Antonio CHIRILLI on 23 May 2011 at 16:40 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 contributions ... More Presented by Dr. Wei LI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: New theoretical developments 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 momentum ... More Presented by Dr. Gergely BARNAFOLDI Type: Parallel Session: Theory developments Track: Jets 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 includ ... More Presented by Andrej FICNAR on 27 May 2011 at 15:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets 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 [1]. Furthermor ... More Presented by Karoly UERMOESSY Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram 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 equation f ... More Presented by Marlene NAHRGANG Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics 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 the ... More Presented by Dr. Naoto TANJI Type: Poster Track: Electromagnetic probes We calculate the nuclear modification factor ($R_{AA}$) of light hadrons by taking into account the initial state momentum anisotropy of the quark gluon plasma (QGP) expected to be formed in relativistic heavy ion collisions. Such an anisotropy can result from the initial rapid longitudinal expansion of the matter. A phenomenological model for the space time evolution of the anisotropic Q ... More Presented by Lusaka BHATTACHARYA Type: Plenary Session: Hard probes I: hadron spectra Track: Jets We report the measurement of transverse momentum spectra of the charged hadrons and photons in √sNN = 2.76 TeV PbPb collisions with the CMS detector. The nuclear modification factors are constructed by dividing the PbPb pT spectra, normalized to the number of binary collisions, by the pp references. Presented by Yen-Jie LEE on 25 May 2011 at 08:55 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production The charm quarks are expected to be produced at the initial fusion of the ultrarelativistic heavy-ion collisions. Just after the production, they will propagate through the Quark Gluon Plasma (QGP) and will loose energy by colliding with quarks and gluons and radiating gluons. We calculate the nuclear modification factor$R_{AA}$of charm quarks, produced from the initial fusion of ... More Presented by Dr. Umme JAMIL Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics We discuss a common feature of all known reactions on nuclear targets - a significant suppression at large Feynman xF and large transverse momenta pT of produced particles. The main emphasis is devoted to production of prompt photons since they are not expected to be accompanied by any final state interaction, either energy loss or absorption. Therefore, besides the Cronin enhancement at medium pT ... More Presented by Jan CEPILA Type: Poster Track: Heavy flavor and quarkonia production The drag and diffusion coefficients of heavy quarks propagating through a baryon rich quark gluon plasma have been calculated. The nuclear suppression factor,$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}$has been highlighted. Presented by Bikash SINHA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: New theoretical developments We have built the nucleon by taking into account explicitly both confinement like in an MIT bag model and a dynamic generation of the quark masses in a Nambu Jona Lasinio model. Therefore, we have supposed a QCD vacuum modified in a cavity and thus a modified quark condensate coming from the presence of three valence quarks in this cavity. Quarks acquire their masses through their interaction wi ... More Presented by Dr. Jean-Christophe CAILLON Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations Results on two-particle angular correlations are presented in proton-proton collisions at center of mass energies of 0.9, 2.36, 2.76 and 7 TeV, over a broad range of pseudorapidity and azimuthal angle. In very high multiplicity events at 7 TeV, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate$p_T$of 1-3 GeV/c, in the kinematic region ... More Presented by Dragos VELICANU on 23 May 2011 at 15:00 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Hadron thermodynamics and chemistry We present the observation of the antimatter$^{4}He$nucleus, the heaviest observed antinucleus. The identification and measurement of anti-$^{4}He$relies on the mean energy loss per unit track length, the time of flight of particles, and their curvature in the magnetic field of the STAR detector. Another essential detector capability was the High Level online tracking Trigger (HLT), which help ... More Presented by Liang XUE on 23 May 2011 at 15:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density 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 systems. ... More Presented by Dr. Margaret MARKOVA Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production 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 electron ki ... More Presented by Dr. Yifei ZHANG on 27 May 2011 at 16:00 Type: Parallel Session: Heavy flavor Track: Heavy flavor and quarkonia production 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 perturbative ... More Presented by Xiaoming ZHANG on 23 May 2011 at 17:50 on 23 May 2011 at 09:30 Type: Plenary Session: Overviews In this talk we summarize the results obtained by ALICE Collaboration in the first Pb-Pb run at LHC. Presented by Juergen SCHUKRAFT on 23 May 2011 at 11:30 Type: Plenary Session: Overviews 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 pseud ... More Presented by Bolek WYSLOUCH on 23 May 2011 at 12:20 Type: Plenary Session: Overviews 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 will present ... More Presented by Dr. Stefan BATHE on 23 May 2011 at 10:40 Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Heavy flavor and quarkonia production Presented by Cesar luiz DASILVA on 27 May 2011 at 09:00 Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 studies; ... More Presented by Prof. Roy LACEY on 23 May 2011 at 18:30 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Hadron thermodynamics and chemistry 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 based o ... More Presented by Alexander Philipp KALWEIT on 23 May 2011 at 15:20 Type: Parallel Session: Pre-equilibrium and initial state Track: Pre-equilibrium and initial state physics 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 model in ... More Presented by Prof. Hirotsugu FUJII on 26 May 2011 at 17:00 Type: Plenary Session: Hard probes I: hadron spectra Track: Jets 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 high-p_T p ... More Presented by Harald APPELSHAEUSER on 25 May 2011 at 08:30 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density 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 interactions ... More Presented by Rolf SCHARENBERG Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes 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 signal-to-background r ... More Presented by Yosuke WATANABE Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations 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 of e ... More Presented by Collaboration CMS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production 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 cross s ... More Presented by Dr. Martino GAGLIARDI Type: Poster Track: Electromagnetic probes 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 produc ... More Presented by Bikash SINHA Type: Parallel Session: Electromagnetic probes Track: Electromagnetic probes 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 sourc ... More Presented by Prof. Charles GALE on 26 May 2011 at 17:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics 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 induced by ... More Presented by Kyrre SKJERDAL Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production When two relativistic nuclei collide with impact parameter larger than twice their radius (b>2R_A), they may interact in several ways: nuclear excitation with neutron emission, two-photon exchange, coherent production of vector mesons with pomeron or gluon exchange. These events are usually referred as Ultra Peripheral Collisions (UPC). A relevant process is the production of vector mesons contai ... More Presented by Daniele DE GRUTTOLA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics The strong electromagnetic fields surrounding the Pb-ions accelerated at the CERN Large Hadron Collider (LHC) allow two-photon and photonuclear interactions to be studied in a kinematic regime so far unexplored. In ultra-peripheral collisions, with impact parameters larger than the sum of the nuclear radii, hadronic interactions are strongly suppressed but the cross sections for electromagnetic or ... More Presented by Prof. Joakim NYSTRAND Type: Plenary Session: New challenges Track: Experiments upgrade, future facilities and instrumentations Presented by Anna STASTO on 28 May 2011 at 10:30 Session: New challenges Track: Experiments upgrade, future facilities and instrumentations Type: Plenary Session: New challenges Track: Experiments upgrade, future facilities and instrumentations Presented by Carlos Albert SALGADO LOPEZ on 28 May 2011 at 10:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram Evidence for the onset of deconfinement in central Pb+Pb collisions was reported by NA49 at the CERN SPS at collision energy 30A GeV. This observation motivated the NA61/SHINE ion program which, in particular, aims to study properties of the onset of deconfinement by measurements of hadron production in p+p, p+A and nucleus-nucleus collisions at the SPS energies. The program started in 2009 when ... More Presented by Antoni ADUSZKIEWICZ Type: Parallel Session: Jets Track: Jets 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 systematic un ... More Presented by William HOROWITZ on 26 May 2011 at 15:40 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Recently, the STAR collaboration has measured the Λ and anti-Λ polarizations in 200 GeV Au-Au collisions [1]. These results can be understood in terms of a model [2], that we proposed recently, based on the hydrodynamical model, and taking into account the effect of the final-state interactions (that occur in the hadronic phase) between the hyperons and other produced particles. These final int ... More Presented by Prof. Celso BARROS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC) has been built in order to identify and characterize the quark gluon plasma (QGP) in high-energy nuclear collisions. As charm quarks are produced at the early stage of the collision, they serve as ideal probes for a QGP. The ALICE detector with its powerful capabilities such as particle identification, vertexing at sub-mil ... More Presented by Robert GRAJCAREK Session: IAC Presented by John HARRIS, Thomas ULLRICH, Dima KHARZEEV on 25 May 2011 at 15:20 Session: Closing Presented by John HARRIS on 28 May 2011 at 11:30 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram The sign problem in lattice QCD prevents us from directly evaluating thermodynamics at real quark chemical potential since the Dirac determinant takes complex value. At imaginary chemical potential, this quantity becomes real thus Monte-Carlo simulation is possible. One needs an analytic continuation to relate a quantity obtained at imaginary chemical potential to a real one. Some charac ... More Presented by Dr. Kenji MORITA Type: Parallel Session: Jets Track: Jets 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 of e ... More Presented by Dr. Nathan GRAU on 24 May 2011 at 17:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets We present a detailed phenomenological study of the associated production of a prompt photon and a heavy quark jet (charm or bottom) in proton-nucleus (p-A) and nucleus-nucleus (A-A) collisions. The dominant contribution to the cross-section comes from the gluon--heavy-quark (gQ) initiated subprocess, making this process very sensitive to the gluon and the heavy-quark nuclear parton densities. ... More Presented by Dr. Tzvetalina STAVREVA Session: Flash talks Presented by Tzvetalina STAVREVA on 27 May 2011 at 11:40 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 heavy ... More Type: Parallel Session: Future facilities and experiment upgrades Track: Experiments upgrade, future facilities and instrumentations 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 heavy ... More Presented by Thomas ULLRICH on 26 May 2011 at 15:00 Session: Flash talks Presented by Natasha SHARMA on 27 May 2011 at 12:10 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets The finely segmented structure and small Moliere radius of the ALICE-PHOS detector allows to separate two photons from a pi^{0} decay at pT=30 GeV/c with an efficiency of about 100%; at even higher pT with smaller efficiency. In this poster, we will present the pi0 production yield measurement with the ALICE-PHOS detector in various centralities in Pb+Pb collisions at sqrt{s_{NN}}=2.76TeV. By c ... More Presented by Dr. Hisayuki TORII Type: Plenary Session: Correlations & fluctuations Track: Hadron thermodynamics and chemistry The ALICE experiment is taking data since 2009, with proton and lead beams. In this talk, we review the different particle identification techniques used by the experiment and the excellent performance during the first year of data taking. We summarize the current results on identified particle spectra in pp collisions at sqrt(s) = 900 GeV and 7 TeV, and in Pb-Pb collisions at sqrt(s_NN) = 2.76 ... More Presented by Michele FLORIS on 26 May 2011 at 09:40 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Hadron thermodynamics and chemistry 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 compa ... More Presented by Dr. Klaus REYGERS on 23 May 2011 at 16:20 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry We present the first results on the production of nuclei and anti-nuclei such as (anti)deuterons, (anti)tritons, (anti)3He and (anti)4He in pp collisions at √s = 7 TeV and Pb-Pb collisions at √sNN = 2.76 TeV. These particles are identified using their energy loss (dE/dx) information in the Time Projection Chamber of the ALICE experiment. The Inner Tracking System gives a precise determination ... More Presented by Natasha SHARMA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations Study of event-by-event fluctuations as a function of collision energy and size of colliding nuclei to search for the critical point of strongly interacting matter is the main goal of the NA61/SHINE experiment at the CERN SPS. First measurements using secondary beams of light nuclei are planned at the end of this year. Study of fluctuations requires a good control over fluctuations caused by the ... More Presented by Alexey KUREPIN Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production We will discuss the ALICE measurement preparation of the fraction of detached J/ψ (detected via its di-electron decay) coming from beauty hadrons semi-inclusive decays, i.e B → J/ψ + X. The measurement relies on the combined use of the ALICE TPC for tracking and particle identification via dE/dx, the ITS for tracking and detection of displaced vertices and the TRD for particle identification. ... More Presented by Carmelo DI GIGLIO Session: IAC Presented by Luisa CIFARELLI-STROLIN on 25 May 2011 at 16:20 Session: IAC Presented by Peter BRAUN-MUNZINGER on 25 May 2011 at 16:00 Session: IAC Presented by Prof. Hideki HAMAGAKI, Kenta SHIGAKI on 25 May 2011 at 15:40 Session: IAC Presented by Kodama TAKESHI on 25 May 2011 at 16:40 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations Forward rapidity region of the high energy particle collisions affords opportunities for studying more details of physics at small Bjorken-x. Measurement of this region within the existing particle experiments is often restricted due to existing framework and limited space. The aim of our project is therefore to develop new super-compact ECAL for the forward region based on the tungsten-scintillat ... More Presented by Libor SKODA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations Abstract: The Cooling Storage Ring (CSR) at Lanzhou, China is a heavy-ion facility that can accelerate nuclei up to 238U with a kinetic projectile energy of several hundred MeV to GeV. By utilizing the CSR heavy-ion beam on an external target, dense QCD matter can be created. The equation of state (EOS) of the strongly coupled matter can be studied via properly chosen physical observables, among w ... More Presented by Cheng LI Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production The main goal of the ALICE experiment is the investigation of the properties of strongly-interacting matter in a very high density deconfined state, that is thought to be formed in Pb-Pb collisions at LHC. The ALICE experiment has collected Pb-Pb data at sqrt{s_NN} = 2.76 TeV and p-p data both at sqrt{s} = 7 and 2.76 TeV. In Pb-Pb collisions, heavy quarks are sensitive probes to test the medium p ... More Presented by Davide CAFFARRI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Hans Hjersing Dalsgaard\footnote{\texttt{<hans.dalsgaard@cern.ch>}}\\ (for the ALICE collaboration) We present the first measurements of the pseudorapidity ($\eta$) distribution in a wide range for different centralities in Pb-Pb collisions at$\sqrt{s_{NN}} = 2.76$TeV. Using the SPD and FMD detectors of ALICE we can cover a wide region in$\eta$:$-3.4<\eta<5$. The distributions yield the ... More Presented by Hans Hjersing DALSGAARD Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 at ... More Presented by Krisztian KRAJCZAR on 23 May 2011 at 15:40 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry The Inner Tracking System is the ALICE detector closest to the beam axis. It is composed of six layers of silicon detectors: two innermost layers of Silicon Pixel Detectors (SPD), two intermediate layers of Silicon Drift Detectors (SDD) and two outermost layers of Silicon Strip Detectors (SSD). The ITS can be used as a standalone tracker in order to recover tracks that are not reconstructed by the ... More Presented by Leonardo MILANO Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram In RHIC and FAIR experiments, it is important to search the position of the critical point and first-order phase boundary in QCD phase diagram. Strong Coupling Lattice QCD has been applied to investigate the chiral phase transition at finite temperature and chemical potential. We take account of the chiral and deconfinement phase transitions in the strong coupling lattice QCD, and investigat ... More Presented by Dr. Takashi NAKANO Type: Parallel Session: Energy scan Track: QCD phase diagram 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 for th ... More Presented by Prof. Misha STEPHANOV on 27 May 2011 at 18:10 Presented by Dr. Panos CHRISTAKOGLOU on 22 May 2011 at 14:15 Type: Parallel Session: QCD Phase diagram Track: QCD at high temperature and density 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 res ... More Presented by Dr. Nan SU on 24 May 2011 at 17:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram We report results on thermodynamic properties of the quark matter obtained by numerical simulations of lattice QCD with dynamical Wilson-type quarks. So far, most of the lattice QCD studies at finite temperature and chemical potential have been performed using staggered-type quark actions with the fourth-root trick for the quark determinant. To control and estimate systematic errors due to lattice ... More Presented by Dr. Shinji EJIRI Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density By means of high energy nuclear collisions, the properties, such as the viscosity coefficients, of QCD matter under extreme conditions are intended to be experimentally revealed. One remarkable result from collisions at RHIC is that the produced hot matter is an almost ideal fluid, obeying the smallest shear viscosity to entropy density ratio observed in nature. Employing an effective ki ... More Presented by Dr. Marcus BLUHM Session: IAC Presented by Yves SCHUTZ on 25 May 2011 at 15:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Pre-equilibrium and initial state physics We show that quantum effects dramatically enhance the production of quarks during nonequilibrium bosonic instabilities. Standard semi-classical descriptions based on the Dirac equation with a homogeneous background field fail to describe nonequilibrium fermion production in presence of non-perturbatively high boson occupation numbers. Our analysis goes beyond this approximation by taking into acco ... More Presented by Daniil GELFAND Type: Parallel Session: Heavy flavor Track: Heavy flavor and quarkonia production 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 hydrodynam ... More Presented by Prof. Rainer FRIES on 23 May 2011 at 18:10 Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Heavy flavor and quarkonia production 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. In particular, ... More Presented by Catherine SILVESTRE on 27 May 2011 at 10:30 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production For 20 years, the suppression of quarkonia has been studied as a probe of the quark gluon plasma (QGP) properties, either by Debye screening of the interaction between the q-qbar pair (Matsui and Satz) or via gluo-dissociation of quarkonia states, which remain strongly bound (Kharzeev). However, the comparison between experimental data and scenarios including suppression mechanisms is not very con ... More Presented by Mr. Hamza BERREHRAH Type: Plenary Session: Heavy flavor and Quarkonia in medium Track: Heavy flavor and quarkonia production 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 new ... More Presented by Gines MARTINEZ-GARCIA on 27 May 2011 at 10:55 Type: Parallel Session: Heavy flavors Track: Heavy flavor and quarkonia production 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 the p ... More Presented by Dr. Jean-Philippe LANSBERG on 24 May 2011 at 16:40 Type: Plenary Session: Hard probes I: hadron spectra Track: Jets 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. Presented by Francois ARLEO on 25 May 2011 at 09:35 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations A Muon Telescope Detector (MTD) is proposed for the upgrade of the STAR (the Solenoidal Tracker At the RHIC) experiment at RHIC. By the measurement of muons of a few GeV/c, the MTD will allow the detection of di-muon pairs from Quark Gluon Plasma (QGP) thermal radiation, quarkonia, and light vector mesons. The correlation of quarks and gluons as QGP resonances, Drell-Yan production, and the mea ... More Presented by Yongjie SUN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Predictions and postdictions from viscous hydrodynamics for the transverse momentum spectra and differential elliptic flow for unidentified and identified charged hadrons from Pb+Pb collisions at LHC energies, including their centrality dependence, will be presented. These predictions are based on a global viscous hydrodynamic fit of soft hadron spectra and their anisotropies measured in Au+Au col ... More Presented by Chun SHEN Type: Poster Session: Pre-equilibrium and initial state 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 loss, ... More Presented by Dr. Marcus BLUHM on 26 May 2011 at 15:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics The BRAHMS collaboration has measured identified particles from AuAu and pp collisions at 200GeV over 3 units of rapidity. We will investigate the scaling of pion and kaon production with Ncoll and Npart at both central and forward rapidities. The kaon to pion ratio serves as a measure of equilibration of strange quarks. BRAHMS has found that for central collisions the K-/K+ ratio is strongly ... More Presented by Dr. Catalin for BRAHMS Collaboration RISTEA Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Transverse energy measurements offer insight into the dynamics of heavy ion collisions and the total entropy created. At very forward angles they may also be sensitive to the low momentum components of the nuclear wave-function. CMS has almost hermetic calorimetry coverage with fine granularity and excellent resolution. In addition for particles near central rapidity momenta from the tracker can b ... More Presented by Collaboration CMS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production The intense electromagnetic fields associated with relativistic heavy ions make a heavy-ion collider a unique tool to study two-photon and photonuclear interactions. In this talk, we present a new measurement of J/psi photoproduction in 200 GeV AuAu collisions at RHIC. The pT distribution of the J/psi mesons peaks at very low pT, consistent with expectations for coherent photoproduction. Both t ... More Presented by Dr. Janet SEGER Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations CMS was designed and optimized to record high luminosity pp collisions. Its powerful DAQ and trigger systems are normally configured to handle very high frequency of relatively low multiplicity pp events. To reduce data volume the CMS sub-detectors are read out using zero suppression algorithms optimized for pp. The large multiplicities expected in PbPb collisions required a different optimiza ... More Presented by Ivan Amos CALI Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production 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 production of ... More Presented by J. Matthew DURHAM on 27 May 2011 at 15:40 Type: Plenary Session: Hard probes I: hadron spectra Track: Jets Presented by Dr. Martin PURSCHKE on 25 May 2011 at 09:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production ALICE is the dedicated LHC experiment to identify and characterize the quark gluon plasma in high-energy nuclear collisions. Due to their large mass and their generation at the early collision stage, heavy quarks are ideal probes. It is still an open question whether the baryon over meson enhancement at intermediate momentum as observed at RHIC also holds for the heavy-quark sector. We report on ... More Presented by Rosa ROMITA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production Open Charm mesons produced in relativistic nuclear reactions are among the most direct probes to investigate the medium produced in these collisions. Ds mesons act as an useful probe to study hadronization mechanism in heavy ion collisions. The study on exclusive reconstruction of the Ds mesons via the decay channel (Ds->KKpi ) for p+p collisions at 7 TeV is presented. The measurement will allow ... More Presented by Dr. Sadhana DASH, Mr. Gian Michele INNOCENTI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics We present a general derivation of relativistic fluid dynamics from the Boltzmann equation using the method of moments. In the 14-moment approximation [1,2], traditionally employed in the fluid-dynamical modeling of heavy-ion collisions, fluid dynamics is obtained by explicitly truncating the moment expansion of the single-particle distribution function. In contrast, in our approach all terms of t ... More Presented by Gabriel DENICOL Type: Parallel Session: Correlations and fluctuations Track: Correlations and fluctuations 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 dimensional ... More Presented by Prof. Joseph KAPUSTA on 23 May 2011 at 19:10 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Hadron thermodynamics and chemistry 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 stra ... More Presented by Dr. Alberto PULVIRENTI on 23 May 2011 at 16:40 Type: Plenary Session: Correlations & fluctuations Track: Correlations and fluctuations 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 functi ... More Presented by Jan Fiete GROSSE-OETRINGHAUS on 26 May 2011 at 11:40 Type: Plenary Session: Overviews Presented by Peter STEINBERG on 23 May 2011 at 11:55 Type: Poster Track: Correlations and fluctuations Observations of a ridge on the near-side, and a dip on the away-side of two-particle correlations measured in central Au + Au collisions have generated considerable interest at RHIC. Are the two phenomena connected? Do they result from jet interactions with the medium, or do they naturally arise from the rapid thermalization and hydrodynamic expansion of collision systems subject to large initial ... More Presented by Claude Andre PRUNEAU Type: Poster Track: Jets Observations of a ridge on the near-side, and a dip on the away-side of two-particle correlations measured in central Au + Au collisions have generated considerable interest at RHIC. Are the two phenomena connected? Do they result from jet interactions with the medium, or do they naturally arise from the rapid thermalization and hydrodynamic expansion of collision systems subject to large initial ... More Presented by Dr. Claude Andre PRUNEAU Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram The physics regarding the existence of the critical point on the QCD phase boundary still remains unclear and its precise location is quite uncertain. We follow the suggestion of T. D. Lee et. al. [Phys. Rev. D9, 2291 (1974)] that a phase transition at high baryon density in a bulk matter can be realized in which nucleon loses part of its mass and thus baryons play a significant role in the phase ... More Presented by Prashant Kumar SRIVASTAVA Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram We investigate effects of the axial anomaly term with a chiral-diquark coupling on the phase diagram within a two-plus-one-flavor Nambu-Jona-Lasinio (NJL) model under the charge-neutrality and$\beta$-equilibrium constraints. We find that when such constraints are imposed, the new anomaly term plays a quite similar role as the vector interaction does on the phase diagram, which the present authors ... More Presented by Dr. zhao ZHANG, Prof. Teiji KUNIHIRO Type: Parallel Session: Theory developments Track: New theoretical developments 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 cou ... More Presented by Prof. Yuri KOVCHEGOV on 23 May 2011 at 16:20 Type: Plenary Session: Hard probes II: true jets Track: Jets Presented by Helen Louise CAINES on 25 May 2011 at 11:15 Type: Plenary Session: Correlations & fluctuations Presented by Paul SORENSEN on 26 May 2011 at 12:00 Type: Plenary Session: Overviews Presented by Hiroshi MASUI on 23 May 2011 at 11:05 Type: Parallel Session: Heavy flavor Track: Heavy flavor and quarkonia production 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 under ... More Presented by wenqin XU on 23 May 2011 at 17:30 Type: Parallel Session: Future facilities and experiment upgrades Track: Experiments upgrade, future facilities and instrumentations 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 matter c ... More Presented by Prof. Carl GAGLIARDI on 26 May 2011 at 16:40 Type: Plenary Session: Correlations & fluctuations Presented by Bedangadas MOHANTY on 26 May 2011 at 08:55 Type: Parallel Session: QCD Phase diagram Track: QCD at high temperature and density 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 over ... More Presented by Prof. Sourendu GUPTA on 24 May 2011 at 16:40 Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 correlator, as ... More Presented by Dhevan GANGADHARAN on 27 May 2011 at 16:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram One of the main goals of the RHIC Beam Energy Scan (BES) program is to search for the QCD critical point and the phase boundary in the QCD phase diagram. Due to high sensitivity to correlation length and direct connection to thermodynamical susceptibilities calculated in Lattice QCD and the Hadron Resonance Gas (HRG) model, higher moments of event-by-event net-proton and net-charge multiplicity di ... More Presented by Dr. Xiaofeng LUO Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram The Relativistic Heavy-Ion Collider (RHIC), at BNL, has undertaken its beam energy scan program in order to probe the QCD critical point. Theoretical calculations reveal that the higher moments of the multiplicity distribution of the conserved quantities like net-charge, net-baryon, net-strangeness are related to the corresponding susceptibilities and the correlation length of the system. Thes ... More Presented by NIHAR R SAHOO Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics We investigate the effects of a temperature-dependent shear viscosity-to-entropy density ratio$\eta/s$on the elliptic flow of hadrons in ultrarelativistic heavy-ion collisions [1]. We use relativistic dissipative fluid dynamics to model the space-time evolution of the hot and dense system formed in such collisions. The final hadron spectra are calculated using the Cooper-Frye freeze-o ... More Presented by Dr. Harri NIEMI on 23 May 2011 at 19:10 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density The high-energy heavy ion collisions at RHIC energies have shown evidence of a new state of matter with very low viscosity to entropy density ratio$\eta/s$similar to that of a nearly ideal fluid. The$\eta/s$is obtained for the QGP with in the context of the Color String Percolation Model (CSPM) using data produced in Au-Au collisions at$\sqrt{s_{NN}}$= 200 A GeV at RHIC and Pb-Pb at$\sqrt{s ... More
Presented by Dr. Brijesh Kumar SRIVASTAVA
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
We simulate an ultra-relativistic gluon gas in a partonic cascade using the Boltzmann Approach for Multi Parton Scattering (BAMPS) with pQCD-based interactions. Furthermore elastic 2<->2 and inelastic 2<->3 processes with constant cross sections are implemented. The hydrodynamic transport parameter shear viscosity is extracted via two different approaches: first from a relativistic stationary velo ... More
Presented by Christian WESP, Felix REINING
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD phase diagram
The QCD phase diagram might exhibit a first order phase transition for large baryochemical potentials. We explore the cosmological implications of such a QCD phase transition in the early universe. We propose that the large baryon-asymmetry is diluted by a little inflation where the universe is trapped in a false vacuum state of QCD. The little inflation period will change the freeze-out crit ... More
Presented by Juergen SCHAFFNER-BIELICH
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Experiments upgrade, future facilities and instrumentations
The Compressed Baryonic Matter (CBM) experiment at the international Facility for Antiproton and Ion Research (FAIR) will conduct a comprehensive research programme on nuclear matter at high net baryonic densities. The fixed-target detector will record hadronic, leptonic and photonic observables from proton-nucleus and nucleus-nucleus collisions. Many of them are rare so that high collision rates ... More
Presented by Johann HEUSER
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: New theoretical developments
In recent years, there has been an increasing interest in dynamics and thermodynamics of non-Abelian plasmas at both very high temperature and density. It is expected that a specific state of matter with unconfined quarks and gluons - the so called quark - gluon plasma (QGP) - can exist. The most fundamental way to compute properties of the strongly interacting matter is provided by the lattice Q ... More
Session: Student lectures
Presented by Paul ROMATSCHKE on 22 May 2011 at 09:50
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: New theoretical developments
Within the framework of a semiclassical approximation the general theory of calculation of effective currents and sources generating bremsstrahlung of an arbitrary number of soft quarks and soft gluons at collision of a high-energy color-charged particle with thermal partons in a hot quark-gluon plasma, is developed. For the case of one- and two-scattering thermal partons with radiation of one or ... More
Presented by Dr. Yuri MARKOV
Type: Parallel Session: Theory developments
Track: New theoretical developments
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 case, w ... More
Presented by Peter ARNOLD on 27 May 2011 at 15:00
Type: Parallel Session: Global and collective dynamics
Track: Global and collective dynamics
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 visco ... More
Presented by Piotr BOZEK on 23 May 2011 at 16:20
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD at high temperature and density
We investigate the massless fermion spectral function coupled with a massive vector boson (mass: m) in the whole region of temperature (T) [1]. The massive vector boson is described as a U(1) gauge boson so that we can analyze the extremely high-T region where T/m $\gg$ 0, in contrast to the Proca formalism [2]. We show that a novel peak appears in the fermion spectral function for T~m in additi ... More
Presented by Teiji KUNIHIRO
Type: Parallel Session: Pre-equilibrium and initial state
Track: Pre-equilibrium and initial state physics
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 behavior. Th ... More
Presented by Dr. Raju VENUGOPALAN on 26 May 2011 at 15:20
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
The hot and dense medium formed in high energy heavy ion collisions may induce shifts of hadronic masses from their asymptotic values. In case this mass modification indeed occurs, it was demonstrated that squeezed correlations of particle-antiparticle pairs, also known as Back-to-Back Correlations (BBC), should appear. They are expected either in the bosonic (bBBC) or in the fermionic (fBBC) case ... More
Presented by Dr. Sandra S. PADULA
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD phase diagram
We calculate the meson screening mass and quark potential in a pion superfluid in the frame of Nambu--Jona-Lasinio model. The most strong potential is always located at the critical point of pion superfluid along any of the axes of temperature and baryon and isospin chemical potentials. Unlike the temperature and baryon density effect, the potential can not be efficiently suppressed in the p ... More
Presented by Mr. Yin JIANG, Prof. Pengfei ZHUANG
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Pre-equilibrium and initial state physics
With the HIJING/BBar v2.0 event generator, we explore the phenomenological consequences of the suppression of perturbative quantum chromo-dynamics (pQCD) mini-jet production and of enhanced "in medium" strong longitudinal color field. Nuclear effects like shadowing and parton energy loss ("jet quenching") are included. This analysis focuses on p+p collisions at centre of mass energy (sqrt(sNN)) ... More
Presented by VASILE TOPOR POP
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
The chemical fluctuations may indicate a presence and determine the position of the critical point on a phase diagram of the QCD matter. This inspired energy and system size scan program of NA61 collaboration at the SPS CERN and low energy scan program of STAR collaboration at the RHIC BNL. However, many other effects -- fluctuations of the number of nucleon participants in A+A collisions, effect ... More
Presented by Dr. Viktor BEGUN
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Experiments upgrade, future facilities and instrumentations
Heavy quarks are fundamental probes to investigate the properties of the hot and dense QCD matter formed at the extreme energy densities reached in Pb-Pb collisions at LHC. The heavy quark pairs (cc_bar and bb_bar), which are produced in the very initial stage of the collision, come out from the interaction region as hadrons, possibly as a part of a jet, and carry out information about the prop ... More
Presented by Cristina TERREVOLI
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
ALICE electromagnetic calorimeters, PHOS (PHOton Spectrometer) and EMCAL (ElectroMagnetic CALorimeter), have the capability to detect and identify photons over a large pT range. The measurement of vector meson ω(782) to π0 γ channel thanks to the calorimeters is interesting both as a test of pQCD and as a probe to explore the properties of hot-dense matter created in heavy-ion collisions. Two c ... More
Presented by Renzhuo WAN
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
Considerable experimental efforts have been devoted to search for the existence of H-dibaryon, a six quark state, proposed by Jaffe[1]. It has also been proposed that the H particle would appear as a bump in the $\Lambda-\Lambda$ invariant mass spectra if the H is a resonance state, or the H would lead to a depletion of the Lambda-\Lambda$correlation near the threshold if the H is weakly bound. ... More Presented by Neha SHAH Type: Parallel Session: Heavy Flavors Track: Heavy flavor and quarkonia production Besides the study of strongly-coupled matter, heavy ion collisions at the LHC provide opportunities to study photon-nucleus and two-photon reactions in a hitherto unexplored energy regimse. Photoproduction of vector mesons off of the strong electromagnetic fields generated by the highly Lorentz-contracted nuclei provides a tool to study the interactions of quark-antiquark dipoles with strong gluo ... More Presented by Dr. Toni BARONCELLI Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production The measurement of single electrons from heavy flavored hadron decays at RHIC indicates strong coupling of heavy quarks to the medium produced in ultra relativistic heavy-ion collisions. At the LHC, heavy quarks are copiously produced. This will allow us to investigate the heavy quark energy loss mechanism in detail and even its quark mass dependence in the medium produced by heavy-ion collisions. ... More Presented by Dr. Min Jung KWEON Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry The ALICE experiment consists of a central barrel covering the pseudo-rapidity range$-0.9<\eta<0.9$and of additional detectors which can be used to define pseudo-rapidity gaps on both sides (\mbox{$-3.7<\eta<-0.9$} and \mbox{$0.9<\eta<5.1$}). The low$p_{T}$threshold of the central barrel gives ALICE a unique opportunity to study the low mass sector of central diffractive production at the LH ... More Presented by Xianguo LU Type: Parallel Session: Jets Track: Jets 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 high ... More Presented by Marguerite Belt TONJES on 24 May 2011 at 15:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations The microscopic string model is employed for the description of femtoscopic characteristics of identical pions produced in pp collisions at energies of sqrt{s} = 200GeV (RHIC) and sqrt{s} = 900GeV (LHC). The strong decrease of the correlation radius with increasing transverse momentum of the pion pair is found in accord to STAR and ALICE experimental observations with flat baselines. I ... More Presented by Mads Stormo NILSSON Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram One of the challenges of present day in nuclear physics is the understanding of the phase transition between the quark gluon plasma and the hadronic world. We can divide space into cells to create a lattice of partons, or describe the transformation of energy via the Cooper-Frye formula, but in these cases we miss some dynamical aspects. That is why I will present a study of the expansion and t ... More Presented by Rudy MARTY Type: Parallel Session: Jets Track: Jets 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 the in ... More Presented by Prof. Hanzhong ZHANG on 26 May 2011 at 16:00 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets Quenching of high transverse momentum hadrons formed in Pb+Pb collisions at the center-of-mass energy of 2.76 TeV is studied within A MultiPhase Transport (AMPT) model. The initial conditions for quark and gluon jet production are obtained from the recently updated HIJING 2.0 model that invokes the latest parton distribution function as well as an energy dependent cut off momentum parameter p_0 fo ... More Presented by Subrata PAL Type: Parallel Session: Jets Track: Jets 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 with ... More Presented by Dr. Gustavo CONESA BALBASTRE on 26 May 2011 at 16:40 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density One of the issues in hot/dense QCD is to understand the state of matter in the vicinity of phase transition from hadronic matter to quark matter expected to be created in heavy-ion collisions, or to be present in the interior of compact stars. In nuclear physics, a scalar meson plays an essential role as known from Walecka model that works fairly well for phenomena near nuclear matter de ... More Presented by Dr. Chihiro SASAKI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations According to the QCD calculations on the lattice, the dynamical fluctuations of, for example, strangeness to entropy ratio could be enhanced in the co-existance region of the first order phase transition from hadronic to partonic degrees of freedom and in the vicinity of the critical point. The energy dependence of the K/pi ratio fluctuations measured by the NA49 experiment in central Pb+Pb col ... More Presented by Dr. Dmytro KRESAN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations In case of chiral U_A(1) symmetry restoration the mass of the eta' boson (the ninth, would-be Goldstone boson) is decreased, thus its production cross section is heavily enhanced. The eta' decays (through one of its decay channels) into five pions. These pions will not be correlated in terms of Bose-Einsten correlations, thus the production enhancement changes the strength of two-pion correlation ... More Presented by Dr. Máté CSANáD Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations An overview of the ALICE EMCal, as installed and operating in 2011, will be presented. Features of the EMCal construction, acceptance and operation will be described together with details of the calibration and performance of the EMCal. Its newly utilized photon triggering and the yet to be approved Jet triggering will be mentioned along with a list of related physics topics (with details gi ... More Presented by Dr. Bjorn NILSEN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations The Inner Tracking System (ITS) of the ALICE experiment consists of six cylindrical layers of silicon detectors, exploiting three different technologies: pixel detectors for the innermost 2 layers, drift detectors for the two central layers and double sided strip detectors for the last two layers. Each layer has hermetic structure in r-phi and it is coaxial with the beam pipe. The ITS covers the ... More Presented by Valerio ALTINI Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Electromagnetic probes The trigger system of the ALICE Electromagnetic Calorimeter (EMCal) aims to enhance the selection of hard-QCD events containing high-p_{T} neutral particles and jets to be recorded. The EMCal shower (photon) trigger (level 0) entered in operation in 2010. The trigger implementation and level 0 decision algorithms will be presented with special focus on the tight timing requirements. Minimum bias d ... More Presented by Jiri KRAL Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 systematically [1 ... More Presented by Ulrich HEINZ, Chun SHEN on 23 May 2011 at 17:30 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations Recent data from heavy ion collisions at RHIC show unexpectedly large near-angle correlations that broaden longitudinally with increasing centrality. The amplitude of this ridge-like correlation rises rapidly, reaches a maximum, and then falls in the most central collisions. In this talk we explain how this centrality dependence arises from an interplay between initial state density fluctuations a ... More Presented by Dr. Paul SORENSEN Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations The STAR detector at RHIC collected its first events in June of 2000. The detector has been upgraded several times since that time and we are continuing to upgrade the system in order to enhance the capabilities of the detector and widen the scope of the research program. In this talk, we will discuss the ongoing upgrades that will conclude in the period between 2011 and 2015. The list of topics i ... More Presented by Dr. Lijuan RUAN Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD at high temperature and density We investigate the single flavor color superconductivity in a magnetic field. Because of the absence of the electromagnetic Meissner effect, forming a nonspherical CSC phase, polar, A or planar, does not cost energy of excluding magnetic flux. We found that these nonspherical phases do occupy a significant portion of the phase diagram with respect to magnetic field and temperature and may be imple ... More Presented by Prof. Defu HOU, Dr. Bo FENG Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production Applying the AdS/CFT correspondence, the expansion of the heavy-quark potential of the${\cal N}$supersymmetric Yang-Mills theory at large$N_c$is carried out to the sub-leading term in the large 't Hooft coupling at both zero and nonzero temperatures. The strong coupling corresponds to the semi-classical expansion of the string-sigma model, the gravity dual of the Wilson loop operator, wit ... More Presented by Prof. Defu HOU, Prof. Ren HAI-CANG, Mr. Zi-Qiang ZHANG Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations Based on the results in the RHIC heavy ion experiments the identification of very high pT particles seems to be extremely interesting at LHC energies. ALICE performes an excellent event by event PID below 5 GeV/c even in those high track densities. However, the track-by-track analysis of the heavy ion data demands further efforts on the experimental side. We are presenting the idea of an ... More Presented by Gergo HAMAR Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram Relativistic heavy-ion collisions represent a practical way to produce Quark-Gluon Plasma in the laboratory. The hydrodynamical model is widely used to describe the evolution of the Quark-Gluon Plasma as a continuous fluid. It has been predicted that in the course of fast expansion this fluid will split into many droplets which later on evolve by evaporating hadrons from the surface. I will presen ... More Presented by Johan Jannik BJERRUM-BOHR Type: Plenary Session: New challenges Track: Experiments upgrade, future facilities and instrumentations Presented by Federico ANTINORI on 28 May 2011 at 11:00 Session: New challenges Track: Experiments upgrade, future facilities and instrumentations Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Heavy flavor and quarkonia production Heavy quarks are considered as one of the essential probes to study the interior of a QGP. The experimental observables contain only the combined information about the expansion of the system and the elementary interaction of heavy quarks with the plasma constituants. In order to asses the latter, we have to understand the influence of different expansion scenarios on the observables. In practice, ... More Presented by Prof. Pol GOSSIAUX Type: Plenary Session: New challenges Track: Experiments upgrade, future facilities and instrumentations Presented by Marcus BLEICHER on 28 May 2011 at 09:30 Type: Parallel Session: Future facilities and experiment upgrades Track: Experiments upgrade, future facilities and instrumentations 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 nuclei ... More Presented by Anne SICKLES on 26 May 2011 at 16:20 Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram We argue that a so far neglected dimensionless scale, the number of neighbors in a closely packed system (Nn, Nn~10 in our world), is relevant for the convergence of the large number of colors (Nc, Nc=3 in our world) expansion at large chemical potential. Using a highly simplified but universal model, we demonstrate that the Nc$\gg$Nn limit is qualitatively different from our world's Nc$\ll$Nn. ... More Presented by Giorgio TORRIERI Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram The realistic equation of state of strongly interacting matter [1,2], that has been successfully applied in the recent hydrodynamic studies of hadron production in relativistic heavy-ion collisions at RHIC [3,4], is used in the Friedmann equation to determine the precise time evolution of thermodynamic parameters in the early Universe [5]. A comparison with the results obtained with simple ideal-g ... More Presented by Wojciech FLORKOWSKI Type: Parallel Session: Global and collective dynamics Track: Global and collective dynamics 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 flow", ... More Presented by Edward SHURYAK on 23 May 2011 at 15:00 Type: Parallel Session: Hadron thermodynamics and chemistry Track: Heavy flavor and quarkonia production 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 u,d,s-carr ... More Presented by Dr. Anton ANDRONIC on 23 May 2011 at 18:30 Track: Electromagnetic probes Electromagnetic probes Track: New theoretical developments AdS/CFT, more Lattice QCD Type: Plenary Session: Overviews Presented by Prof. Krishna RAJAGOPAL on 23 May 2011 at 09:00 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics The geometrical overlap region in non-central heavy ion collisions is almond shaped. Due to this shape profile, density fluctuations for different harmonics are strongly correlated; for example v1 and v3. If the final momentum space distributions in heavy-ion collisions depend on the initial density, then the coupling of different harmonics will lead to three particle correlations such as cos(phi_ ... More Presented by Jim THOMAS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: Jets Two-particle correlations at RHIC and SPS in heavy-ion collisions have shown away-side structures that could be explained by conical emission, either from Mach-cone shock waves or Cerenkov gluon radiation, or other physics mechanisms such as path-length dependent energy loss or deflection by radial flow. Three-particle correlations at RHIC showed evidence of conical emission. More recently, trian ... More Presented by Jason Glyndwr ULERY Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram Non-Abelian vortices are topologically stable objects in the color-flavor locked (CFL) phase of dense QCD. We derive a dual Lagrangian starting with the Ginzburg-Landau effective Lagrangian for the CFL phase, and obtain topological interactions of non-Abelian vortices with quasi-particles such as$U(1)_B$Nambu-Goldstone bosons (phonons) and massive gluons. We find that the phonons couple to the t ... More Presented by Yuji HIRONO Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Hadron thermodynamics and chemistry The studies of strange particle production provide information about the dynamics of the system which was created in Pb-Pb or pp collisions at LHC energies. Reconstruction of strange particles based on their decay topology allow us to extract yields over a large transverse momentum range (from ~ 0.6 GeV/c up to ~ 8 GeV/c). The ALICE experiment provides high statistics data from proton-proton and P ... More Presented by Marian PUTIS Type: Poster Session: Poster Session 2 + Wine and Cheese Track: QCD phase diagram Lattice computations as well ab initio continuum QCD calculations show a broad crossover for both chiral symmetry restoration and the deconfinement transition at vanishing density. Particularly, the change of the order parameter for deconfinement, the Polyakov loop, occurs in a rather broad temperature interval. In contrast, current Polyakov loop extended effective models show steeper slopes in a ... More Presented by Rainer STIELE Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Experiments upgrade, future facilities and instrumentations The future Compressed Baryonic Matter (CBM) experiment, to be operated at the FAIR facility at GSI, Darmstadt, aims at the exploration of the properties of dense baryonic matter. In particular, the search for in-medium modifications of hadrons, the study of the transition from hadronic to partonic degrees of freedom and the experimental search for a critical endpoint in the phase diagram of strong ... More Presented by Christina DRITSA Type: Parallel Session: QCD Phase diagram Track: QCD phase diagram The QCD transition is studied on lattices up to Nt=16. The strange susceptibility the chiral condensate and the renormalized Polyakov loops are presented. The equation of state is determined on lattice with Nt-6,8,10 and at some temperature values with Nt=12. The pressure, the trace anomaly, the energy and entropy density and the speed of sound are presented as functions of the temperature in the ... More Presented by Zoltan FODOR on 24 May 2011 at 15:40 Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics The ALICE detector allows precise measurements of the transverse energy in p+p and Pb-Pb collisions at LHC energies. We will discuss studies of the transverse energy in p+p collisions at sqrt{s} = 0.9, 2.76, and 7 TeV and in Pb-Pb collisions at sqrt{s_{NN}} = 2.76 TeV. The ALICE Inner Tracking System (ITS) and the Time Projection Chamber (TPC) are used for precise measurements of the transverse ... More Presented by Dr. Christine NATTRASS Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Studies on transverse momentum (pt) distributions, the mean pt values and yield ratios of pions, kaons and protons at mid rapidity (|y|<0.5) for different charged particle multiplicities and event shapes in pp collisions at √s=7 TeV are reported. The changes in the shape of the pt distribution of pions, kaons and protons as a function of charged particle multiplicity and degree of azimuthal iso ... More Presented by Cristian ANDREI Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Correlations and fluctuations A study of the linearized sphericity in minimum bias proton-proton collisions at$\sqrt{s}$= 0.9 and 7 TeV with the ALICE detector at the LHC is presented. The observable was measured in the plane perpendicular to the beam direction and using primary charged tracks in$|\eta|\leq0.8$. The average sphericity as a function of multiplicity is reported for events with different hardness (soft'' an ... More Presented by Antonio ORTIZ VELASQUEZ Type: Poster Session: Poster Session 1 + Wine and Cheese Track: Global and collective dynamics Triangular flow (v3) can arise from event-by-event fluctuations. Its connection to fluctuations in the initial state collision geometry may reveal hydrodynamic information of the collision system. Theoretical studies suggest its sensitivity to hydrodynamic evolution may even be stronger than elliptic flow (v2). We present v3 measurement by the 2-, 4-, and 6-particle cumulant method at$\sqrt{s_{ ... More
Presented by Li YI
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
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 the ... More
Presented by Dr. Andrew ADARE on 24 May 2011 at 15:00
Type: Parallel Session: Global and collective dynamics
Track: Global and collective dynamics
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 gove ... More
Presented by Dr. Stefan FLOERCHINGER on 27 May 2011 at 18:10
Type: Poster Session: Poster Session 1 + Wine and Cheese
With the two freeze-out model for the hadron production in the relativistic heavy-ion collisions, hadron ratios and their momentum spectra measured at RHIC are fitted. In this model the chemical freeze-out occurs earlier at higher temperature. In analyzing the hadron ratios, resonance contribution has been carefully taken into account. After the chemical freeze-out the number of the thermal hadron ... More
Presented by Kang Seog LEE
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
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 RHIC, r ... More
Presented by Jorge MERCADO on 23 May 2011 at 17:30
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD phase diagram
Incorporating the background instanton effects, we extend the chiral random matrix model to include the anomaly effect. The anomaly effect appears naturally as the flavor mixing determinant interaction terms, which are missed in the conventional random matrix models. Due to the determinant interaction terms, the model shows the second-order phase transition for two massless-quark flavors and ... More
Presented by Takashi SANO
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD at high temperature and density
We discuss that the fermion spectrum at an ultrasoft energy region ($\ll$g^2T) in quantum electrodynamics and quantum chromodynamics at high temperature T, where g is the coupling constant. We show that the fermion propagator has a pole at v|p|-i\gamma, where p is the momentum, v=1/3 is the velocity, and \gamma is the damping rate of order g^2T log(1/g). The residue of the pole is weak of order g^ ... More
Presented by Daisuke SATOW
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
In a pp collision the jet signature has to be decoupled from the soft or semi-hard bulk of particles originating from beam-remnant fragmentation, initial and final state radiation and multi-partonicinteractions: the so-called Underlying Event. Besides being a baseline for jet studies, its characterization provides insight into the non-perturbative phenomenology in high energy collisions and, in pa ... More
Presented by Sara VALLERO
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
Description of heavy-ion collisions, where modifications of the fragmentation functions due to interaction of partons with the hot and dense medium are expected, is a challenging task and requires a detailed understanding of small collision systems such as p+p and d+Au. Comparison of measurements in p+p and d+Au collisions can be further used to disentangle initial state effects from cold nuclear ... More
Presented by Dr. Jana BIELCIKOVA
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Correlations and fluctuations
In event-by-event hydrodynamics, the initial distribution of participants in the azimuthal plane fluctuates from event to event. We study the dipole asymmetry $\epsilon_1$, eccentricity $\epsilon_2$, and triangularity $\epsilon_3$, as a function of centrality, both analytically as well as numerically. These Fourier harmonics of the initial-state geometry have been shown to largely determine the ... More
Presented by Prof. Rajeev BHALERAO
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: New theoretical developments
The fast thermalization of Quark Gluon Plasma, as suggested by hydrodynamical simulation, is one of the central questions of heavy ion collisions. Theoretical understanding of the mechanism involves field theory out of equilibrium. While the perturbative method becomes less effective due to the strong coupling, the gauge/gravity duality can play an important role. In [1], we studied a gravitationa ... More
Presented by Dr. Shu LIN
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Pre-equilibrium and initial state physics
Two different forms of unintegrated gluon distributions have been widely used in the literature to describe small-x phenomena. On one hand, the Weizsacker-Williams distribution explicitly counts the number of gluons per state in a physical gauge but does not seem to be related to any known observables. On the other hand, the unintegrated gluon distribution defined as the Fourier transform of the c ... More
Presented by Fabio DOMINGUEZ
Type: Parallel Session: Correlations and fluctuations
Track: Correlations and fluctuations
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 conservatio ... More
Presented by Dr. Anthony TIMMINS on 24 May 2011 at 15:40
Type: Poster Track: Experiments upgrade, future facilities and instrumentations
Back-to-back jet produced by hard parton scatterings (di-jet) is an unique and powerful probe to quantify the properties of Quark Gluon Plasma at LHC. In the ALICE experiment, the electromagnetic calorimeter (EMCal) provides a crucial role to reconstruct jets with a good energy resolution, together with the information by Time Projection Chamber (TPC). In order to enhance the capability of bac ... More
Presented by Shintaro KUBOTA
Type: Poster Track: Heavy flavor and quarkonia production
Upsilon production in heavy ion collisions at RHIC energy is investigated. While the transverse momentum spectra of the ground state Upsilon(1s) are controlled by the initial state Cronin effect, the excited (b b-bar) states are characterized by the competition between the cold and hot nuclear matter effects and sensitive to the dissociation temperatures determined by the heavy quark potential. We ... More
Presented by Prof. Pengfei ZHUANG, Mr. Yunpeng LIU, Dr. Nu XU
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Heavy flavor and quarkonia production
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 medium suppression in the Quark Gluon Plasma. Although various features of heavy quar ... More
Presented by Dr. Sascha VOGEL
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
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. We perform simulations [1] of the Pb+Pb heavy ion collisions at LHC at 1.38 + 1.38 TeV/nucl within the three module model. The initial stages of the reaction, before the thermal equilibrium is reached, are ... More
Presented by Laszlo Pal CSERNAI
Type: Parallel Session: Hadron thermodynamics and chemistry
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 freeze-o ... More
Presented by Reinhard STOCK on 23 May 2011 at 16:00
Type: Parallel Session: Hadron thermodynamics and chemistry
Track: Electromagnetic probes
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 proper ... More
Presented by Alessandro DE FALCO on 23 May 2011 at 19:10
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
We present recent results from the newly developed hybrid code VISHNU [1] which couples viscous hydrodynamics for the quark-gluon plasma (QGP) with a hadron cascade model for the late hadronic stage. By describing the hadronic rescattering and freeze-out stage microscopically, we improve on earlier purely hydrodynamic models which required additional adjustable parameters to describe the transpor ... More
Presented by Dr. Huichao SONG
Type: Parallel Session: Global and collective dynamics
Track: Global and collective dynamics
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 essent ... More
Presented by Akihiko MONNAI on 27 May 2011 at 16:40
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: Global and collective dynamics
Relativistic Navier-Stokes hydrodynamics is acausal and unstable. These problems are solved by introducing relaxation times into the constitutive equations of the viscous tensors. We derive the microscopic formulae of the shear and bulk viscous relaxation times by using the projection operator method. In the leading-order of perturbative calculation, we find the ratios of the viscosities and corre ... More
Presented by Dr. Xu-Guang HUANG
Type: Poster Session: Poster Session 1 + Wine and Cheese
Track: New theoretical developments
P-odd effects related to medium vorticity are discussed. In particular, we suggest studying a separation of baryonic charge due to the large baryonic chemical potential. This separation could be manifested in neutron asymmetries in heavy ion collisions in the FAIR and NICA energy range. We analyze the vorticity in various chaotic flows in detail. Chaotic flows are generalized in a nontrivial way r ... More
Presented by Prof. Alexander SORIN
Type: Parallel Session: Electromagnetic probes
Track: Electromagnetic probes
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 PbPb ev ... More
Presented by Jorge A ROBLES on 26 May 2011 at 15:00
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: QCD phase diagram
We discuss the novel view at the colour confinement which, on the one hand, allows us to find out the surface tension coefficient of quark gluon bags and, under a plausible assumption, to determine the endpoint temperature of the QCD phase diagram, on the other hand. The developed model considers the confining colour tube as the cylindrical quark gluon bag with non-zero surface tension. A ... More
Presented by Prof. Kyrylo BUGAIEV
Session: New challenges
Track: Experiments upgrade, future facilities and instrumentations
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 parton d ... More
Type: Parallel Session: Future facilities and experiment upgrades
Track: Experiments upgrade, future facilities and instrumentations
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 parton d ... More
Presented by Nestor ARMESTO PEREZ on 26 May 2011 at 15:20
Session: New challenges
Track: Experiments upgrade, future facilities and instrumentations
Session: Flash talks
Type: Poster Session: Poster Session 2 + Wine and Cheese
Track: Jets
The Photon Spectrometer of the ALICE experiment, PHOS, has performed extensive measurements of neutral meson production in proton-proton collisions at the energies of 0.9, 2.76 and 7 TeV. Inclusive spectra of pi0 and eta mesons were measured in mid-rapidity in a wide transverse momentum range. Dependence of the pi0 spectrum on event multiplicity has been also studied. Comparison with pQCD calculat ... More
Presented by Dr. Yuri KHARLOV