# Quark Matter 2012

12-18 August 2012
US/Eastern timezone

• wyslouch@mit.edu
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Displaying 533 contributions out of 533
Type: Poster Session: Poster Session Reception
We study the evolution of the quark-gluon composition of the plasma created in ultra-Relativistic-Heavy Ion Collisions (uRHIC's) employing a partonic transport theory that includes both elastic and inelastic collisions plus a mean fields dymanics associated to the widely used quasi-particle model. The latter, able to describe lattice QCD thermodynamics, implies a "chemical" equilibrium ratio betwe ... More
Presented by Prof. Vincenzo GRECO on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Plenary VIB: Flash Talks
Hadronic resonances can play a pivotal role in providing experimental evidence for partial chiral symmetry restoration in the deconfined quark-gluon phase produced in high energy nucleus-nucleus collisions. 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 sign ... More
Presented by Masayuki WADA on 18 Aug 2012 at 10:10
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Open heavy flavour hadrons produced in high-energy ion collisions are an interesting tool to investigate the properties of the QCD medium, as they come from the hadronization of heavy quarks which are created in the early stage of the interaction and which experience the whole collision history. Energy loss of heavy quarks in the medium can be investigated by comparing the heavy flavour productio ... More
Presented by Riccardo RUSSO on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 5A: Hadron Thermodynamics and Chemistry (Chair R. Stock)
The excellent particle identification capabilities of the ALICE experiment allow the studies of (anti) matter and hyper-matter production. (Anti) deuterons, tritons, 3He and 4He as well as the corresponding antinuclei can be cleanly identified based on their specific energy loss in the Time Projection Chamber and velocity information in the Time-Of-Flight detector. The (anti) hyper-triton signal c ... More
Presented by Benjamin DOENIGUS on 16 Aug 2012 at 15:20
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The Time Projection Chamber (TPC) is the central tracking device of the ALICE experiment, providing momentum measurement and particle identification via the specific energy loss dE/dx. The readout rate of the TPC is presently limited by the necessity to prevent ions from the amplification region of the MWPC-based readout chambers to drift back into the drift volume, which is achieved through activ ... More
Presented by Taku GUNJI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6E: Initial State and p-A (Chair E. Wang)
Track: New theoretical developments
We propose a new mechanism for generating a single transverse spin asymmetry (STSA) in polarized proton-proton and proton-nucleus collisions in the high-energy scattering approximation. In this framework the STSA originates from the q -> q G splitting in the projectile (proton) light-cone wave function followed by a perturbative (C-odd) odderon interaction, together with a C-even interaction, b ... More
Presented by Mr. Matthew SIEVERT on 17 Aug 2012 at 14:20
We discuss the phase diagram of quantum chromodynamics (QCD) at finite T and finite quark chemical potential \mu. In particular, we focus on the QCD critical point(s), which has attracted considerable attention in its search at the relativistic heavy ion collision experiments. However, not only the location, but even the existence has not yet been settled. In this talk, we show that the critical ... More
Presented by Dr. Yoshimasa HIDAKA on 17 Aug 2012 at 14:00
Hydrodynamics predicts long-lived sound and shear waves. Thermal fluctuations in these waves can lead to the diffusion of momentum density, contributing to the shear viscosity and other transport coefficients. Within viscous hydrodynamics in 3+1 dimensions, this leads to a positive contribution to the shear viscosity, which is finite but inversely proportional to the microscopic shear viscos ... More
Presented by Paul ROMATSCHKE on 16 Aug 2012 at 14:20
Type: Poster Session: Poster Session Reception
Track: QCD at finite temperature and density
We propose a QCD-like theory with the Z_{Nc} symmetry. The flavor-dependent twisted boundary condition (TBC) is imposed on Nc degenerate flavor quarks in the SU(Nc) gauge theory. The QCD-like theory is useful to understand the mechanism of color confinement. Dynamics of the QCD-like theory is studied by imposing the TBC on the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. The Z_{Nc} symm ... More
Presented by Dr. Yuji SAKAI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 5C: High pt and Jets (Chair B. Cole)
The CUJET1.0 Monte Carlo Jet Energy loss model is applied to predict the jet flavor, centrality and density dependence of the nuclear modification factor $R_{AA}$ and the elliptic flow $v_2$ at RHIC and LHC. Running coupling effects due to combined $x$, $k_\perp$ and $q_\perp$ evolution are included for the first time in the dynamical DGLV opacity expansion framework and are shown to provide a nat ... More
Presented by Alessandro BUZZATTI on 16 Aug 2012 at 15:40
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
Conceived and constructed over a decade ago, the PHENIX detector was designed to discover the Quark-Gluon Plasma (QGP). Following on this discovery,the PHENIX collaboration has embarked on a number of upgrades to study the QGP properties in detail, with the next step being a significant overhaul of the PHENIX detector called sPHENIX. sPHENIX includes upgrading the central detector with a compa ... More
Presented by Eric MANNEL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
Dileptons are unique probes of the strongly-coupled Quark Gluon Plasma (QGP) created in relativistic heavy-ion collisions. Compared to hadrons, leptons have little interaction with the QGP medium and can thus travel through the entire system with most of the original information intact. This feature allows us to study the properties of the medium during its space-time evolution. The low mass reg ... More
Presented by Kurt JUNG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The PHENIX experiment at the Relativistic Heavy Ion Collider recently took data in p+p and Au+Au collisions with a new silicon vertex detector (VTX). This upgrade detector is capable of measuring the off-vertex decay of heavy flavor decay electrons via distance of closest approach (DCA). The resulting measured DCA distributions will be a convolution of the parent meson momenta, decay lifetimes, an ... More
Presented by Michael MCCUMBER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
In this talk, I present an effective model based on the linear representation of the chiral U(N_f)_r x U(N_f)_l symmetry of QCD. It is demonstrated that a reasonable fit of the mass parameters and coupling constants of the model to hadron vacuum properties can be obtained. This study can contribute to answering the question about the quark content of the scalar isoscalar mesons. The model is used ... More
Presented by Dirk RISCHKE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The flexibility of the beam species available at the Relativistic Heavy Ion Collider has enabled the PHENIX Collaboration to examine open heavy flavor production across a wide range of temperature, energy density, and system size. Charm and bottom production in $p+p$ collisions, which is dominated by gluon fusion, is largely consistent with FONLL pQCD calculations. New analysis techniq ... More
Presented by J. Matthew DURHAM on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
The radial flow parameters are important quantities in relativistic heavy ion collisions [1]. They constrain the equation of state [2] and in particular, the anisotropic parameter relates to shear viscosity [3]. They are usually extracted from the spectrum of transverse momentum by the parameterizations of Blast-wave model [4]. In the present work, we suggest a direct measure of radial veloc ... More
Presented by Prof. Yuanfang WU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
A high momentum particle identification detector is under discussion by the ALICE experiment at CERN as part of its plan for high luminosity data taking in the next decade. The VHMPID detector is improving on well established ring imaging Cerenkov technology by using a pressurized gas volume in a focussing geometry to minimize the radial depth of the device. In this configuration the VHMPID can be ... More
Presented by Austin Vincent HARTON on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: New theoretical developments
We calculate a way to acquire some current quark mass from a general relativistic effect. For a bare quark, we model that boundary conditions on the spacetime metric can plausibly couple the value of current quark mass to the charge, via external pressure (e.g., as supplied by a background field) at sub-fm length scales. This mechanism acquires some (up to ~ 40%) current quark mass “from” th ... More
Presented by Dr. Thomas KIESS on 16 Aug 2012 at 16:00
Presented by Adam TRZUPEK on 13 Aug 2012 at 17:40
Presented by Barbara Krystyna WOSIEK on 13 Aug 2012 at 12:00
Type: Oral Presentation Session: Plenary IIA: Jets (Chair M. Gyulassy)
Presented by Martin SPOUSTA on 14 Aug 2012 at 08:50
Type: Oral Presentation
Presented by Dr. Phil PLAIT on 17 Aug 2012 at 20:45
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
A forward electromagnetic calorimeter (FoCal), to be placed in the pseudorapidity range of $2.5<\eta<4.5$, is being discussed as one of the upgrade plans for the LHC-ALICE experiment. One of the motivations for building such a detector is the study of direct photons, as well as correlations including photons, pions and jets in pp,pA and AA collisions at the highest LHC energies. Such measurements ... More
Presented by Nikola for the ALICE-FoCal collaboration POLJAK on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Neutral pion production measured with the ALICE detector in Pb-Pb collisions at the LHC is an important tool to study the properties of the hot and dense medium created in heavy-ion collisions. The neutral pion yield, obtained with the ALICE electromagnetic calorimeter in pp collisions at sqrt(s) = 2.76 and 7 TeV, as well as in Pb-Pb collisions at sqrt(s_NN) = 2.76, is analyzed in terms of x_t ... More
Presented by Xiangrong ZHU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
We calculate flow observables with the NeXSPheRIO ideal hydrodynamic model and make the first comparison to the complete set of mid- rapidity flow measurements made by the PHENIX collaboration in top energy Au+Au collisions. A simultaneous calculation of v2, v3, v4, and the first event-by-event calculation of quadrangular flow defined with respect to the v2 event plane (v4{psi2}) gives good ... More
Presented by Dr. Frederique GRASSI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 7D: Correlations & Fluctuations (Chair B. Wosiek)
Track: Correlations and fluctuations
The properties of the produced matter in a heavy-ion collision can be experimentally studied by measuring the azimuthal anisotropy in the momentum distribution of the produced particles. Quantified by the anisotropic flow coefficients, v_n, and corresponding symmetry planes, psi_n, such anisotropy is expected to reflect the shape of the initial energy density of the collision. We report on the mea ... More
Presented by Ante BILANDZIC on 17 Aug 2012 at 17:10
The anisotropic flow of identified particles is an important observable to probe the freeze-out properties, the parton energy loss and the partonic phase of the system created in heavy-ion collisions. We report on the elliptic and triangular flow measurements for a number of identified particles such as charged pions, kaons and (anti-)protons, as well as K0s , Λ/anti-Λ, Ξ, and Ω. The results a ... More
Presented by Francesco NOFERINI on 17 Aug 2012 at 14:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
The $\phi$-meson flow is seen as an important observable to study hydrodynamic behavior and partonic collectivity of heavy-ion collisions. We present detailed measurements of $\phi$-meson flow in $\sqrt{s_{NN}}$=2.76 TeV Pb--Pb collisions with the ALICE detector. The results are compared to the flow of other identified particles (kaons, pions, antiprotons, lambdas, cascades ) to investigate the ma ... More
Presented by You ZHOU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: QCD at finite temperature and density
Quantum vortices in the color-flavor locked (CFL) phase of QCD have bosonic degrees of freedom localized on them, called the orientational zero modes. We show that the orientational zero modes are electromagnetically charged. As a result, a vortex in the CFL phase nontrivially interacts with photons. We show that a lattice of vortices acts as a polarizer of photons with wavelengths larger than som ... More
Presented by Mr. Yuji HIRONO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
Anomalous soft photon production beyond that predicted by standard Bremsstrahlung calculations is a ubiquitous feature in high energy processes, from e+e- to heavy ion collisions. We calculate the electromagnetic current due to the QCD vacuum polarization induced by the qq jets in e+e- annihilation using the Schwinger model, and source Maxwell’s equations with it. The predicted soft photon emiss ... More
Presented by Joshua ILANY on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Information about the evolution of the system formed during the high energy p + p collisions can be obtained by investigating the charged particle ratios. The particle ratios serve as an important indicator of the collision dynamics [1]. These can be used to probe the process of hadronization in high energy collisions. In this poster, we will present measurements of mid-rapidity antiparticle to pa ... More
Presented by Shikshit GUPTA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The main difficulty in precise and systematically controlled jet measurements in heavy-ion collisions is the correction for the soft underlying background fluctuation as well as for additional hard scatterings occurring in the nucleus-nucleus collision. To minimize non-trivial biases in jet-quenching measurements by imposing kinematical constraints on the jet fragmentation and to suppress backgrou ... More
Presented by Mr. Christopher YALDO on 16 Aug 2012 at 16:00
Presented by Daniel CEBRA on 13 Aug 2012 at 15:55
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
We present the azimuthal correlation of charm, anti-charm pairs produced at LHC energies. We show our results for both proton on proton collision as well as lead on lead collision. An empirical model has been included to show the effect of energy loss on the correlation . Separately an effect of collective flow using blast wave model on the correlation is also shown.
Presented by Mohammed YOUNUS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
Single inclusive hadron production in the forward rapidiy region in deuteron-gold collisions is well understood in the Color Glass Condensate (CGC) framework. As a complement to single inclusive spectra, detailed information is obtained with two-particle correlations. Recent measurements of the azimuthal angle correlations at RHIC have shown that there is a strong suppression of the away side pe ... More
Presented by Heikki MäNTYSAARI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The measurement of heavy-flavour (charm and beauty) production in ultra-relativistic heavy ion collisions provides an important test of the parton energy loss mechanism and its predicted color charge and parton mass dependencies. The suppression of electron yields from semi-leptonic decays of D and B mesons in Pb-Pb collisions at the LHC has been observed to be large. Because of the dead-cone effe ... More
Presented by Deepa THOMAS on 16 Aug 2012 at 16:00
Di-hadron azimuthal angular correlations in the forward rapidity region of deuteron-nucleus collisions at RHIC show a disappearance of the away side peak with centrality and transverse momentum. This can be understood, in the Color Glass Condensate (CGC) formalism, to be due to multi-gluon exchanges between the projectile and target. We show that CGC formalism predicts a similar disappearance of t ... More
Presented by Jamal JALILIAN-MARIAN on 15 Aug 2012 at 09:10
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Azimuthal anisotropy harmonics have been measured in ultra-central PbPb collisions at a center-of-mass energy per nucleon pair of 2.76 TeV. Top central 0.2\% PbPb collisions have been collected using a unique trigger on total energy at forward hadronic calorimeter and total multiplicity of hits on pixel tracker by the CMS experiment during 2011 LHC PbPb run. A total of about 1.8 million ... More
Presented by Wei LI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 1C: Correlations & Fluctuations (Chair J. Schukraft)
Track: Jets
Measurements of the azimuthal anisotropy of charged hadrons are presented for PbPb collisions at 2.76 TeV over an extended transverse momentum range up to approximately 60 GeV/c. The data were collected with the CMS detector at the LHC. Utilizing a novel and unique high-pT single-track high-level trigger, the analysis explores the full 2011 PbPb data set corresponding to an integrated luminosity o ... More
Presented by Victoria ZHUKOVA on 14 Aug 2012 at 15:55
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
In ultra-relativistic heavy-ion collisions, charm and beauty quarks are a sensitive tool to probe the flavour and mass dependence of the parton interaction with the medium created in such interactions, the Quark-Gluon Plasma. The level of thermalization of heavy quarks can be studied via the azimuthal anisotropy of their emission in the transverse plane, the elliptic flow v2, at low transverse mo ... More
Presented by Bogdan Theodor RASCANU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
The possible creation of a strongly interacting deconfined phase (Quark-Gluon plasma) in relativistic heavy ion collisions would be measurable in a delayed hadronization time. It was proposed to test this hypothesis via the measurement of correlations between positive and negatively charged pairs pairs as a function of rapidity, the so-called Balance functions, which was done at SPS and RHIC energ ... More
Presented by Alis RODRIGUEZ MANSO on 16 Aug 2012 at 16:00
A baryon anomaly – an increase baryon-to-meson production ratio at intermediate transverse momenta in heavy-ion collisions when compared to proton–proton collisions – is observed at RHIC and the LHC. This effect is usually explained by recombination of constituent quarks during QGP hadronisation, or as a consequence of a strong radial flow developed during the heavy-ion collision. In this co ... More
Presented by Karel SAFARIK on 15 Aug 2012 at 11:40
Type: Oral Presentation Session: Parallel 7B: Exploring the QCD Phase Diagram (Chair H. Huang)
Track: Exploring the QCD phase diagram
We discuss the effects of the global baryon and electric charge conservation on the cumulants of net baryon and net proton fluctuations [1], which are considered to be sensitive probes of the QCD critical point. We show that the cumulants are substantially suppressed if the conservation laws are taken into account. We propose a new observable that is not influenced by the global baryon conservatio ... More
Presented by Adam BZDAK on 17 Aug 2012 at 17:10
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We discuss the influence of the chiral phase transition on the properties of the probability distribution of conserved charges based on effective chiral models and on the Landau theory of phase transition [1]. Statistical fluctuations of the net baryon number have been regarded as a diagnostic tool of the chiral phase transition in QCD and in heavy ion collisions. Normally, they are discuss ... More
Presented by Dr. Kenji MORITA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
The study of resonances production in p-p collisions provides constraints on QCD-inspired particle production models. In Pb-Pb collisions, resonances are good probes to estimate the collective properties of the fireball and may add constraints to the estimate of its lifetime. $p_T$ spectra have been measured for the baryonic resonances $\Lambdastar$, $\Sigmastar$ and $\Xistar$ using data col ... More
Presented by Enrico FRAGIACOMO on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 1A: Global & Collective Dynamics (Chair U. Heinz)
Track: Global and collective dynamics
A primary goal of the RHIC Beam Energy Scan (BES) is to search for evidence of a transition between a hadron gas and a Quark Gluon Plasma. The dependence of $v_{1}$ and higher flow harmonics on system size and beam energy may be sensitive to the degrees of freedom in the system, as a consequence of early pressure gradients and a potential softening in the equation of state. In this talk, we ... More
Presented by Yadav PANDIT on 14 Aug 2012 at 14:55
Type: Oral Presentation Session: Parallel 5A: Hadron Thermodynamics and Chemistry (Chair R. Stock)
Track: Global and collective dynamics
The hyperon-nucleon(Y-N) interaction is of great physical interest because it introduces a new quantum number strangeness in nuclear matter. It is predicted to be the decisive interaction in some high-density matter systems, such as neutron stars [1]. RHIC, the Relativistic Heavy Ion Collider, provides an ideal laboratory to study Y-N interaction because hyperons and nucleons are abundantly produc ... More
Presented by Ms. Yuhui ZHU on 16 Aug 2012 at 15:40
Type: Oral Presentation Session: Parallel 5A: Hadron Thermodynamics and Chemistry (Chair R. Stock)
Track: Global and collective dynamics
Strange hadron production is sensitive to parton dynamics in nucleus-nucleus collisions. In particular, the strange quark production rate and its subsequent evolution in the dense partonic medium depend on the beam energy and the net baryon density. We will present STAR measurements of $K^{0}_{s}$, $K^{\pm}$, $\phi$, $\Lambda$, $\Xi$, and $\Omega$ at mid-rapidity from Au+Au collisions at $\sqrt{s_ ... More Presented by Dr. Xiaoping ZHANG on 16 Aug 2012 at 15:00 Type: Poster Session: Poster Session Reception Track: Exploring the QCD phase diagram The study of correlations between opposite sign charge pairs can provide a powerful tool to probe the properties of the quark-gluon plasma (QGP). The balance function, which measures the correlations between opposite sign charge pairs, is sensitive to the mechanisms of charge formation and the subsequent relative diffusion of the balancing charges. The study of the balance function can provide inf ... More Presented by Hui WANG on 16 Aug 2012 at 16:00 In part to search for a possible critical point (CP) in the phase diagram of hot nuclear matter, a beam energy scan was performed at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory. The STAR experiment collected significant Au+Au data sets at beam energies,$\sqrt{\rm s_{\rm NN}}$, of 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV. Lattice and phenomenological calculations ... More Presented by Daniel MCDONALD on 17 Aug 2012 at 16:50 Presented by Urs WIEDEMANN on 13 Aug 2012 at 09:30 Type: Poster Session: Poster Session Reception Track: Hadron thermodynamics and chemistry The short lifespan of the QCD phase at RHIC and LHC suggests fast filamenting disintegration of the supercooled QGP state of matter. The ensemble of all produced hadrons carry information about the physical properties of the disintegrating QGP. For example the energy content is obtained evaluating the energy carried by all hadrons. Considering that many of the particles have not been measured, ex ... More Presented by Michal PETRAN on 16 Aug 2012 at 16:00 Type: Oral Presentation Session: Parallel 3A: Global & Collective Dynamics (Chair T. Kodama) Track: Global and collective dynamics We study the effects of bulk viscosity on$p_T$spectra and elliptic flow in heavy ion collisions. For this purpose we compute the dissipative correction$\delta f$to the single particle distribution functions in leading-log QCD, and in kinetic models of a hadronic resonance gas. We find that for a near conformal fluid the bulk viscosity is suppressed by two powers of the conformal bre ... More Presented by Thomas SCHAEFER on 15 Aug 2012 at 08:30 The in-medium modification of a hard jet is reformulated to consider the process of a hard parton propagating through a finite sized QCD medium, held at a fixed high temperature and vanishing chemical potential. The process is factorized into a hard part representing the propagation and scattering of the parton, and a soft part representing the non-perturbative color field experienced by the jet i ... More Presented by Dr. Abhijit MAJUMDER on 16 Aug 2012 at 14:00 Type: Poster Session: Poster Session Reception Track: Correlations and fluctuations Azimuthal emission spectra of various hadron species in ultra-relativistic heavy ion collisions at$\sqrt{s_{NN}} \approx $200 GeV exhibit a curious hierarchy at intermediate$p_t$($\approx 2-3$GeV). Rather than being ordered by mass, the spectra seem to be ordered by whether the species is a baryon or meson. It is seen that when the elliptic flow$v_2$and transverse momentum$p_T$are both sc ... More Presented by John CAMPBELL on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: New theoretical developments We present new solutions for holographic falling string models of light quark jet energy loss that suggest a linear path dependence of energy loss, dE/dx ~ x^1, without the nonlinear x^2 dependence assumed previously. This effect, combined with non-conformal deformations and higher curvature corrections of AdS geometry, is shown to be able to account for the small relative reduction of the jet-med ... More Presented by Andrej FICNAR on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Electroweak probes Dilepton production has been proposed to serve as a penetrating probe for the hot and dense medium created in high-energy nuclear collisions. Their small final-state interaction cross sections, let dileptons escape the interaction region undistorted. Since dileptons originate from all stages of a heavy ion reaction, their sources vary with the kinematic phase space under consideration: In the ... More Presented by jie ZHAO on 16 Aug 2012 at 16:00 The RHIC Beam Energy Scan (BES) program aims to study the QCD phase diagram. The main focus is to search for signals of the hypothesized critical point and the onset of the quark-hadron phase transition. The BES program covers a large part of the QCD phase diagram ($T$vs.$mu_{B}$). With its uniform acceptance and excellent particle identification, STAR has collected large event samples in the$mu ... More
Presented by SABITA DAS on 17 Aug 2012 at 15:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Di-leptons are ideal probes of the strongly interacting hot and dense medium created at RHIC. They are not affected by the strong interaction once produced, therefore they can probe the whole evolution of the collision. The di-leptons spectra in the intermediate mass range ($1.1<M_{ll}<3.0$ GeV/$c^{2}$) are directly related to thermal radiation of the Quark-Gluon Plasma (QGP). In the low mass ran ... More
Presented by Xiangli CUI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
A recent theoretical study indicates that a chiral magnetic wave at finite baryon density could induce an electric quadrupole moment in the quark-gluon plasma produced in heavy ion collisions. The quadrupole deformation will lead to a difference in azimuthal anisotropy $v_2$, between positive and negative pions, and the magnitude of this difference is predicted to be proportional to net charge asy ... More
Presented by Hongwei KE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
With a multi-phase transport model including initial charge separation and string melting, the charge azimuthal correlations for Au+Au collisions at center of mass energies 200, 39, 11.5, 7.7 GeV and Pb+Pb collisions at 2.76 TeV are investigated. Initial charge separations of about 10 % for 200 GeV, 5 % for 39 GeV, 0 % for 11.5 GeV appear to be necessary. This is consistent with decreasing Chiral ... More
Presented by Guo-Liang MA on 16 Aug 2012 at 16:00
The puzzle of the fall-off of the same-side ridge in relative pseudorapidity, found in unbiased two-particle correlations, is solved. We show that the event-by-event hydrodynamics followed by statistical hadronization with proper charge conservation provides the crucial non-flow component and leads to agreement with the data at soft transverse momenta (p_T < 2 GeV). The fall-off of the same-side r ... More
Presented by Piotr BOZEK on 14 Aug 2012 at 18:05
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Three-particle correlations have been used to probe for local parity violation (LPV) in the quark-gluon plasma (QGP) formed during Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV at RHIC [1]. Further expanding on this analysis, we present our results on looking at these correlations through pairing kaons and pions produced during the collision events (while fixing the third particle to be another pi ... More
Presented by Charles RILEY on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Charge dependent azimuthal correlations relative to the reaction plane measured by the STAR collaboration at RHIC and ALICE at the LHC are consistent with expectations from the strong local parity violation in QGP manifesting itself via the Chiral Magnetic Effect. The background to these measurements comes from interplay of strong anisotropic flow and correlations not related to CME. In this stud ... More
Presented by Jocelyn MLYNARZ on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 5C: High pt and Jets (Chair B. Cole)
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 energy loss mechanism. The ATLAS detector at the LHC accumulated 150µb-1 of lead-lead data at 2.76 TeV per nucleon-nucleon pair. Due to the excellent cap ... More
Presented by Petr BALEK on 16 Aug 2012 at 14:40
Type: Poster Session: Poster Session Reception
Almost all charm in heavy ion collisions is produced in the hard 'first interaction' processes before partons thermalize into a drop of QGP. Charm survives the QGP evolution and as hadrons emerge in soft hadronization processes, practically every charm or anticharm quark turns into a charmed hadron, small fraction of the charm yield enters multi-charmed hadrons and charmonium states. We assume t ... More
Presented by Michal PETRAN on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
The charm quark production will be reasonably large at LHC energies, both in p+p and Pb+Pb collisions. In heavy ion collisions even quark coalescence channels will strongly influence the charmed baryon and meson production. Furthermore, the formation of an intense coherent gluon field in Pb+Pb collisions results in additional heavy quark-antiquark pairs. Thus the primary charm quark momentum distr ... More
Presented by Peter LEVAI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: QCD at finite temperature and density
The question of the existence of a confining matter with restored chiral symmetry at low temperatures and large density has been studied within the confining and chirally symmetric model, assuming a rigid quark Fermi surface. However, in the confining matter near the Fermi surface quarks group into color-singlet baryons. Due to the interaction between quarks the quark Fermi surface gets diffuse ... More
Presented by Mr. Vasily SAZONOV on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
One of today's main goals in high energy physics is the exploration of the phase diagram of nuclear matter. On the theoretical side, much effort has been put into the investigation of quantum chromodynamics (QCD), its phase diagramm and symmetries. An important property of the QCD Lagrangian is its approximate chiral symmetry in the light-quark sector. At low temperatures and density this appr ... More
Presented by Christian WESP on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
For about a decade it is known that topological fluctuations -- instantons -- are modified by the nonzero Polyakov line VEV and split into Nc dyons. By now there is extensive lattice literature confirming this fact and explaining certain observations by properties of such dyons, mostly at T=(1-2)Tc. This talk report the first direct simulations of the statistical mechanics of the dyonic ... More
Presented by Edward SHURYAK on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
The shear to viscosity ratios ($\eta/s$) are obtained for the QGP 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 $\sqrt{s_{NN}}$ = 2.76 TeV at LHC \cite{per}. The experimental transverse momentum spectrum is used to measure the percolation density parameter $\xi$ in Au-Au collisions (STAR)\cite ... More
Presented by Dr. brijesh SRIVASTAVA on 16 Aug 2012 at 16:00
While the study of the quark-gluon plasma has been the primary focus of the RHIC experiments, much work has also been done to understand so-called cold nuclear matter (CNM) effects through $d$+Au collisions where no hot plasma is produced. Effects such as nuclear shadowing, Cronin enhancement, and initial-state parton energy loss, among others, are not only interesting in their own right, but hav ... More
Presented by Baldo SAHLMUELLER on 15 Aug 2012 at 09:30
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
$\Upsilon(1S+2S+3S)$ are measured in $d$ + Au and $p$ + $p$ collisions at $\sqrt{s_{NN}}$= 200 GeV by the PHENIX experiment in the di-muon decay channel at 1.2 < |y| < 2.2. Compared to the $J/\psi$, the $Upsilon$'s heavier mass makes it possible to study the nuclear effects on the gluon distribution in different kinematic regions than those probed by the $J/\psi$. The measured results are ... More
Presented by Kwangbok LEE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: QCD at finite temperature and density
I discuss the structure and composition of massive (two solar-mass) neutron stars containing deconfined quark matter in color superconducting states. Stable configurations featuring such matter are obtained if the equation of state of hadronic matter is stiff above the saturation density, the transition to quark matter takes place at a few times the nuclear saturation density, and the repulsive ve ... More
Presented by Dr. Armen SEDRAKIAN on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
The collective flow of charged hadrons emitted in heavy ion collisions can be characterized using the Fourier coefficient $v_2$ (elliptic flow), as well as with the higher order coefficients, $v_3$, $v_4$, etc, which result primarily from fluctuations in the initial conditions of the colliding nuclei.The latter is of paramount importance since it can provide insight on the hydrodynamic behavior of ... More
Presented by Damian REYNOLDS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Heavy-ion collisions at relativistic energies ofer an unique opportunity to probe highly excited dense nuclear matter with properties very diferent from that of a hadron gas or ordinary nuclear matter in the laboratory. An interesting phenomenon at the kinetic freeze-out stage of the system evolution is the collective transverse expansion as it is entirely generated during the collision and theref ... More
Presented by Prof. Alexandru JIPA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 1A: Global & Collective Dynamics (Chair U. Heinz)
Track: Global and collective dynamics
We present a systematic study on the evolution of hadron spectra and their azimuthal anisotropy from the lowest collision energy studied at the Relativistic Heavy Ion Collider (RHIC), √s = 7.7A GeV, to the highest energy reachable at the Large Hadron Collider (LHC), √s = 5500A GeV [1]. As the collision energy increases, the resulting increases of the initial temperature, and fireball lifetime, ... More
Presented by Chun SHEN on 14 Aug 2012 at 15:15
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
The observed suppression of high transverse momentum ($p_{T}$) hadrons in central Au+Au collisions at $\sqrt{s_{NN}}$ = 200GeV, expressed via the nuclear modification factor $R_{AA}$ ($R_{CP}$), is a clear indication of partonic energy loss due to the strongly-coupled medium created in heavy-ion collisions. That result is supported by high-$p_{T}$ triggered azimuthal di-hadron correlations which c ... More
Presented by Stephen HORVAT on 16 Aug 2012 at 16:00
The recent jet measurements at RHIC and the LHC have challenged the heavy-ion community to a better understanding of jet fragmentation in the presence of the Quark-Gluon-Plasma (QGP). Jet fragmentation in vacuum is well described by perturbative QCD and is characterized by color coherence effects that lead to the angular ordering of successive branchings along the jet. To investigate the alter ... More
Presented by Dr. Yacine MEHTAR-TANI on 16 Aug 2012 at 15:20
Type: Oral Presentation Session: Parallel 1D: Heavy Flavor & Quarkonia (Chair R. Granier de Cassagnac)
Track: Heavy flavor and quarkonium production
We employ a kinetic rate-equation approach in a thermally expanding medium to compute the suppression and regeneration of quarkonia in heavy-ion collisions [1]. The in-medium properties of quarkonia figuring into the rate equation (widths, binding energies and heavy-quark masses) are constrained by euclidean correlators from lattice QCD. Input cross sections for heavy quarks and quarkonia, as wel ... More
Presented by Ralf RAPP on 14 Aug 2012 at 15:55
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Constraining properties of the strongly interacting state of matter produced in relativistic heavy ion collisions at RHIC and LHC, such as eta/s and T_{init} is one of the biggest priorities in the field of heavy ion physics. For this purpose, we have developed CHIMERA, a framework for performing global statistical evaluation of multiple QGP signatures by comparing key soft observables (spectra, ... More
Presented by Dr. Irakli GARISHVILI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
Recently, the mass of the pulsar PSR J1614-2230 has been measured at a one-percent accuracy to be roughly two solar masses. This, in addition to the statistical analysis of neutron-star radii by Steiner, Lattimer, and Brown lead to tight constraints for the equation of state of dense baryonic matter inside the neutron star. We combine a realistic phenomenological equation of state at low densities ... More
Presented by Dr. Thomas HELL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
Data taken over the last several years have demonstrated that the Relative Heavy Ion Collider (RHIC) has created dense and rapidly thermalizing matter. The next objective at RHIC is to study properties of this partonic matter in detail in terms of color degrees of freedom and the equation of state. The precise measurement of transverse momentum distributions of quarkonia at different centralities, ... More
Presented by Yi WANG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Higher cumulant ratios of conserved charges are suggested to be sensitive probe of QCD critical end point [1] in relativistic heavy ion collisions. Their behaviors at current relativistic heavy ion collisions are highly interested and studied intensively [2,3]. Before we draw the critical-like fluctuations from the measured higher cumulants, it is necessary to know what the contributions of conven ... More
Presented by Prof. Yuanfang WU on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 1B, Jets (Chair X.N. Wang)
Gamma-hadron correlations measured in heavy-ion collisions produced at the LHC allow to investigate medium induced jet modifications in a transverse momentum (p_t) range below 50 GeV/c, where jet reconstruction is challenging because of the relatively large contribution from the underlying event. At high p_t direct photons, produced in Compton and annihilation QCD leading order processes, are asso ... More
Presented by Nicolas ARBOR on 14 Aug 2012 at 15:15
Previous top-down studies of jet stopping in strongly-coupled QCD-like plasmas with gravity duals have been in the infinite 't Hooft coupling limit $\lambda \to \infty$. They have found that, though a wide range of jet stopping distances are possible depending on initial conditions, the maximum jet stopping distance $\ell_{\rm max}$ scales with energy as $E^{1/3}$ at large energy. But it has alw ... More
Presented by Peter ARNOLD on 16 Aug 2012 at 14:40
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Higher moments of net-baryon are suggested to be sensitive probe of QCD critical end point [1] in relativistic heavy ion collisions. Their critical fluctuations are highly interesting and instructive for the exploration of QCD phase diagram from both theoretical and experimental sides. According to the universality of critical behavior, the QCD critical end point, and the chiral phase trans ... More
Presented by Prof. Yuanfang WU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The measurement of J/psi production in proton-proton collisions at the LHC energy regime allows to test QCD calculations. In addition, it provides the necessary reference for the ALICE Pb-Pb program. ALICE collected proton-proton collisions at sqrt{s} = 7 and 2.76 TeV in 2010 and 2011. In this talk, we present the latest results on J/psi production in proton-proton collisions, measured by ALICE a ... More
Presented by Fiorella FIONDA on 16 Aug 2012 at 16:00
The properties of the hot and dense QCD medium formed in ultra-relativistic heavy ion collisions, as well as the mechanism of in-medium partonic energy loss, can be accessed via the measurement of the nuclear modification factor of particle production. The measurement of D meson production provides key tests of parton energy-loss models, which predict that charm quarks should experience less in-m ... More
Presented by Alessandro GRELLI on 17 Aug 2012 at 14:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The ALICE experiment at the Large Hadron Collider (LHC) has been designed in order to characterize the quark gluon plasma (QGP) in high-energy heavy-ion collisions. D mesons are powerful probes of the medium since the charm quarks are produced at the early stage of the collision and experience its entire evolution. In particular, the anisotropy parameter $v_2$ of D mesons is sensitive to the degre ... More
Presented by Grazia LUPARELLO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Due to their relatively high mass, heavy-flavour quarks, produced in high-energy heavy-ion collisions, are sensitive probes of the interaction dynamics inside the hot and dense QCD matter. Since heavy quarks are produced in pairs during the initial stage of the collision, before the formation of the QGP, the measurement of heavy-flavour hadron production provides profound information on the prop ... More
Presented by Sandro BJELOGRLIC on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Angular di-hadron correlation studies in Au+Au collisions at 200 GeV have revealed a nearisde elongated structure in delta eta. This is often referred to as the ridge, and was found to extend to delta eta 9 units at the LHC. Using preliminary STAR data [3], we discuss methods to decompose 2D di-hadron correlations in Au+Au 200 GeV collisions on the nearside. Our analysis is performed as a function ... More
Presented by Chanaka DE SILVA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
We study the nonequilibrium dynamics of a quark fluid coupled to a sigma field and a Polyakov loop near the QCD phase boundary. As the system evolves through the first order transition line, baryon density fluctuations are enhanced in comparison with an evolution through the crossover or the critical point.
Presented by Christoph HEROLD on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 7E: New Theoretical Developments (Chair P. Levai)
Track: New theoretical developments
We derive the splitting kernels for partons produced in large Q^2 scattering processes that subsequently traverse a region of strongly-interacting matter using a recently-developed effective theory Soft Collinear Effective Theory with Glauber Gluons (SCETG). We include all corrections beyond the small-x approximation, consistent with the power counting of SCETG. We demonstrate how medium recoil, g ... More
Presented by grigory OVANESYAN on 17 Aug 2012 at 16:50
Type: Oral Presentation Session: Parallel 1A: Global & Collective Dynamics (Chair U. Heinz)
Track: Global and collective dynamics
We present a general derivation of relativistic fluid dynamics from the relativistic Boltzmann equation using the method of moments [1]. The main difference between our approach and the traditional 14-moment approximation is that we do not close the fluid-dynamical equations of motion by truncating the expansion of the single-particle momentum distribution function. Instead, we keep all the terms ... More
Presented by Gabriel DENICOL on 14 Aug 2012 at 15:55
The HBT measurement provides the information on the space-time evolution of particle emitting source in relativistic heavy ion collisions. Azimuthal component of 3D HBT radii relative to event plane gives us the information of the source shape at freeze-out. It also provides the information of the system evolution by comparing with the initial source shape. The recent measurement of higher harmon ... More
Presented by Takafumi NIIDA on 14 Aug 2012 at 14:15
Type: Oral Presentation Session: Parallel 2D: Heavy Flavor & Quarkonia (Chair J.-P. Blaizot)
Track: Heavy flavor and quarkonium production
The three Y states (1S, 2S, 3S) can be separated using the CMS experimental apparatus via their dimuon decays in both pp and heavy-ion collisions. A suppression of the Y(1S) and Y(2S) mesons is observed in PbPb collisions at sqrt(sNN) = 2.76 TeV, compared to the yield in pp collisions scaled by the number of inelastic nucleon-nucleon collisions. Furthermore, a suppression of the excited Y states h ... More
Presented by Guillermo BRETO RANGEL on 14 Aug 2012 at 16:45
Type: Oral Presentation Session: Parallel 1D: Heavy Flavor & Quarkonia (Chair R. Granier de Cassagnac)
Track: Heavy flavor and quarkonium production
CMS has measured the nuclear modification factors of prompt J/psi in PbPb collisions at sqrt(sNN) = 2.76 TeV. For prompt J/psi with relatively high pT (6.5 < pT < 30 GeV/c), a strong, centrality-dependent suppression is observed in PbPb collisions, compared to the yield in pp collisions scaled by the number of inelastic nucleon-nucleon collisions. During the 2011 data taking period the data sample ... More
Presented by Dong Ho MOON on 14 Aug 2012 at 14:15
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The W+Si electromagntic sampling calorimeter has been proposed as one of the upgrade plans for the LHC-ALICE experiment. The role of this calorimeter is to add capabilities to measure direct photons, pi0's and jets over full azimuth in a forward rapidity region (2.5<eta<4.5). The physics goal with the calorimeter is to understand the dynamics and properties of strongly interacting matter create ... More
Presented by Taku for the ALICE-FOCAL Collaboration GUNJI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The Compressed Baryonic Matter (CBM) experiment will conduct a comprehensive research programme on nuclear matter at high net baryonic densities. The Silicon Tracking System (STS) is the central detector of the CBM experiment. Its task is the standalone trajectory reconstruction of the high multiplicities of charged particles originating from high-rate beam-target interactions. The detector system ... More
Presented by Dr. Juergen ESCHKE on 16 Aug 2012 at 16:00
The number of quark ($n_q$) scaling, which is manifested as $v^{hadron}_{2}(p_T) \approx n_q*v_2(p_T/n_q)$, is an approximate scaling that comes from the addition of the valence quark momenta at hadronization. The observation of $n_q$ scaling has been claimed that a partonic matter with quark-like degrees of freedom and significant collectivity has been generated in heavy ion collisions~\ref ... More
Presented by Dr. shengli HUANG on 15 Aug 2012 at 11:00
Presented by Frank GEURTS on 16 Aug 2012 at 08:30
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
Di-electrons are among the most promising probes for studying the early, hot and dense stages created in relativistic heavy-ion collisions. They are color neutral and so interact only electromagnetically, thus carrying to the detectors information about the conditions and properties of the medium at the time of their creation. The di-electrons are emitted over the the entire space-time evol ... More
Presented by Deepali SHARMA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3C: Electro-Weak Probes (Chair J. Kapusta)
Track: Electroweak probes
Di-leptons serve as clean and bulk penetrating probes to study the properties of the strongly interacting hot and dense medium created in heavy ion collisions. They are produced in all stages of the heavy-ion collisions and are not affected by strong interactions, hence can probe the entire evolution of the collision. Di-lepton production in the low mass range ($M_{ll}<1.1$ GeV/$c^{2}$) allo ... More
Presented by Dr. Huang BINGCHU on 15 Aug 2012 at 09:10
Type: Poster Session: Poster Session Reception
Track: Jets
A di-jet produced by a hard scattering of partons plays a vital role to characterize the properties of hot and dense QCD matter produced in Pb-Pb collisions at LHC. In particular, a di-jet is one of the key probes to look for a medium response due to a strong jet quenching effect, as reported by the CMS and ATLAS collaborations. In this analysis, we used the data collected by the ALICE collaborati ... More
Presented by Tatsuya CHUJO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
In the years 2010/11, the Solenoidal Tracker At RHIC (STAR) conducted a Beam Energy Scan (BES) over a wide range of center-of-mass energies with the purpose of studying the properties of the Quark-Gluon-Plasma (QGP) as well as searching for the onset of deconfinement and the critical point of the QCD phase diagram. The installation of the Barrel Time-Of-Flight-Detector (TOF) has enabled STAR to id ... More
Presented by Mr. Patrick HUCK on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3C: Electro-Weak Probes (Chair J. Kapusta)
Track: Electroweak probes
Measurements of lepton pair spectra are a crucial tool to map out the evolution of the hot dense matter created in ultra-relativistic heavy ion collisions. At low pair mass, direct photons and low mass vector mesons are the main center of interest. Interpretation of lepton pair production rates in excess of expectations from hadronic decays observed by PHENIX and how the data constrains theoretica ... More
Presented by Dr. Ermias ATOMSSA on 15 Aug 2012 at 08:50
Type: Oral Presentation Session: Parallel 6E: Initial State and p-A (Chair E. Wang)
As the foundation of high energy hadronic physics, QCD factorization enables us to separate the short distance perturbative physics from the long distance non-perturbative effects. Its prediction power relies on the universality of the parton distributions among different processes. In our recent publication [1], we established an effective factorization in hard processes in nuclei scattered by a ... More
Presented by Feng YUAN on 17 Aug 2012 at 15:20
Type: Poster Session: Poster Session Reception
Track: Jets
Recent experimental data measured in \sqrt{s}=2.76 TeV Pb+Pb collisions by ATLAS and CMS showed a significant imbalance in the transverse momenta of the two reconstructed jets with the highest transverse momenta. This momentum imbalance is assumed to be caused by the different energy and momentum loss of the di-jets by scatterings within the created medium. To investigate this momentum loss we ext ... More
Presented by Mr. Florian SENZEL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
The ALICE experiment is dedicated to the study of the quark gluon plasma in heavy-ion collisions at the CERN LHC. The Muon Forward Tracker (MFT) is under consideration by the ALICE Experiment to be part of its programme of detectors upgrade to be installed during the LHC shutdown planned for 2018. The MFT is a silicon pixel detector added in the Muon Spectrometer acceptance ($2.5 < \eta < 4$) upst ... More
Presented by Antonio URAS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The direct photon - hadron pair correlations serve as an excellent probe of the hot and dense medium created in the heavy ion collision at RHIC. The unmodified photon is used as a reference for the modification of the jet energy by the medium. The low cross section of QCD Compton scattering that produces direct photon - quark pairs added with the enormous production of the background photons requi ... More
Presented by Nowo RIVELI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Direct photons are a unique probe that allows studying the different stage of ultrarelativistic heavy-ion collisions. The direct photon yield is sensitive to different production mechanisms, which dominate the expected direct photon spectra at different transverse momenta. Their production is also influenced by modifications of the initial state in heavy nuclei. Such modifications can be studied i ... More
Presented by Baldo SAHLMUELLER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: New theoretical developments
We have studied the effect of shear viscosity effects on direct photons as well as lepton pair production from Quark Gluon Plasma (QGP). The production rate for both these two thermodynamic signals gets modified due to: (i) changed space-time evolution of the viscous fluid and (ii) non-equilibrium correction to the equilibrium distribution function. The non-equilibrium correction grows with viscos ... More
Presented by Bikash SINHA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The proposed MPC-EX detector is a Si-W preshower extension to PHENIX's existing Muon Piston Calorimeter (MPC). The MPC-EX consists of eight layers of alternating W absorber and Si mini-pad sensors. Located at large rapidities, 3.1 < |$\eta$| < 3.8, the MPC-EX and MPC access low-x partons in the Au nucleus in d+Au collisions. With the addition of the MPC-EX, the neutral pion reconstruction rang ... More
Presented by Sarah CAMPBELL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We present the first extraction of the recently-proposed rapidity-even directed flow observable v1, obtained from an analysis of published two-particle correlation data from the ALICE Collaboration. An accounting of the correlation due to the conservation of transverse momentum restores the factorization seen in all other Fourier harmonics and thus indicates that the remaining correlation gives a ... More
Presented by Ekaterina RETINSKAYA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Directed flow, v1, is measured over a wide range of pseudo-rapidity, |eta|<5.1, in Pb-Pb collisions at 2.76 TeV with ALICE at the LHC. The results of v1 are reported as a function of the pseudo-rapidity and the transverse momentum for different collision centrality classes. Using the neutral spectator deflection at beam rapidity we investigate both the rapidity asymmetric v1 which is sensitiv ... More
Presented by Gyulnara EYYUBOVA on 16 Aug 2012 at 16:00
on 17 Aug 2012 at 09:50
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
The first results of the heavy ion program at LHC [1] suggest that the near-perfect fluidity discovered at RHIC is a universal property of the quark-gluon plasma (QGP) above and around the crossover temperature. The recent developments in hydrodynamic studies take account of the effects of shear and bulk viscosities as well as fluctuations for the quantitative understanding of the hot medium. On t ... More
Presented by Akihiko MONNAI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 7E: New Theoretical Developments (Chair P. Levai)
Track: New theoretical developments
We demonstrate that the shear viscosity of a two-component mixture of point-like partices has a non-trivial time dependence, which is induced by the intrinsic coupling between the two particle species. The shear viscosity coefficient of a mixture calculated using the Green-Kubo relation does not have this time dependence and hence is not sufficient to describe dissipatie hydrodynamic behavior of a ... More
Presented by Andrej EL on 17 Aug 2012 at 17:10
Type: Oral Presentation Session: Parallel 6E: Initial State and p-A (Chair E. Wang)
We have recently performed a numerical study of the forward correlations between the lepton-pair and associated hadrons in Drell-Yan process in pA collisions. Using the present knowledge of the dipole gluon distribution from the modified Golec-Biernat-Wusthoff model and from the solution of the Balitsky-Kovchegov evolution equation, we are able to compute and predict the forward correlations betwe ... More
Presented by David ZASLAVSKY on 17 Aug 2012 at 14:40
Type: Oral Presentation Session: Parallel 6B: Exploring the QCD Phase Diagram (Chair K. Rajagopal)
Track: Exploring the QCD phase diagram
Strong fluctuations in observables are believed to provide decisive signals for identifying phase transitions of QCD in relativistic heavy-ion collisions. To study this possibility under realistic conditions of the expansion and the cooling of the fireball we performed dynamic simulations within our approach of nonequilibrium chiral fluid dynamics. Based on an effective phase transition model, chi ... More
Presented by Dr. Marlene NAHRGANG on 17 Aug 2012 at 15:40
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
In hydrodynamical modeling of the ultrarelativistic heavy-ion collisions the freeze-out is typically performed at a constant temperature. In this work we introduce a dynamical freeze-out criterion, which compares the hydrodynamical expansion rate with the pion scattering rate [1]. Previous studies [2] have shown that differences between constant temperature and dynamical freeze-out criteria are sm ... More
Presented by Pasi HUOVINEN on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
Higher cumulants of baryon number are suggested to be good probe of Critical Point of QCD phase transition in relativistic heavy ion collisions [1]. However, since the number of produced protons is still small at RHIC, it is pointed out [2] that the statistical fluctuation is not negligible, and should be subtracted from directly measured cumulants. So the dynamical cumulant ratios are sugge ... More
Presented by Mr. Zhiming LI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 2A: Global & Collective Dynamics (Chair A. Poskanzer)
Track: Global and collective dynamics
Hydrodynamic models enjoy much success in describing and predicting the bulk dynamics of relativistic heavy ion collisions. Recent studies have clearly shown that including initial and final fluctuations is essential for detailed study of the evolving QGP. So far, however, not many studies appeared which incorporate both fluctuations at the same time. Here we present our first results in inclu ... More
Presented by Sangyong JEON on 14 Aug 2012 at 18:05
Presented by Abhay DESHPANDE on 17 Aug 2012 at 11:50
Presented by Hannah PETERSEN on 17 Aug 2012 at 10:05
Type: Oral Presentation Session: Parallel 4D: Pre-Equilibrium & Initial State (Chair T. Ludlam)
Track: Global and collective dynamics
Hadron spectra and elliptic flow in high-energy heavy-ion collisions are studied within a (3+1)D ideal hydrodynamic model with fluctuating initial conditions given by the AMPT Monte Carlo model and compared to experimental data. Fluctuation in the initial energy density comes from not only the coherent soft interaction of overlapping nucleons but also the number of mini-jets within each binary nuc ... More
Presented by Long-Gang PANG on 15 Aug 2012 at 11:20
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
The TOTEM experiment at LHC measured the differential cross-section of elastic p+p scattering at 7 TeV, with the help of Roman Pot detectors placed as close as seven times the transverse beam size from the outgoing beams [1]. Results indicate an initial exponential decrease of dsigma/dt, followed by a significant diffractive minimum at |t| = (0.53 +- 0.01(stat) +- 0.01(syst)) GeV**2. For large |t| ... More
Presented by Mate CSANAD on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
One of the most advocated probes of the quark gluon plasma (QGP) properties is the $J/\psi$ suppression. However, the comparison between experimental data and theoretical scenarios is still rather inconclusive, as several mechanisms might participate to explain the observed suppression (sequential suppression, dynamical or statistical recombination, formation time,...), not to mention the cold nuc ... More
Presented by Hamza BERREHRAH on 16 Aug 2012 at 16:00
We calculate electric and baryonic charge fluctuations on the lattice. Results have been obtained with the highly improved staggered quark action (HISQ) and almost physical quark masses on lattices with temporal extent of N_tau=6,8,12. Higher cumulants of the net-charge distributions are increasingly dominated by a universal scaling behavior, which is arising due to a critical point of QCD in the ... More
Presented by Dr. Christian SCHMIDT on 16 Aug 2012 at 14:40
Type: Oral Presentation Session: Parallel 1B, Jets (Chair X.N. Wang)
Track: Jets
Tagged jet measurements provide a promising experimental channel to quantify the similarities and differences in the mechanisms of jet production in proton-proton and nucleus-nucleus collisions. We present the first calculation of the transverse momentum asymmetry of $Z^0/\gamma^*$-tagged jet events in $\sqrt{s}=2.76$~TeV reactions at the LHC. Our results combine the ${\cal O}(G_F\alpha_s^2)$ pert ... More
Presented by Dr. Ivan VITEV on 14 Aug 2012 at 15:35
Charmonium production in heavy ion collisions has been studied at diff erent energies and with diff erent collision systems over the last few decades, ever since the J/psi suppression induced by color screening of its constituent quarks was proposed as a signature of the formation of a quark gluon plasma (QGP) in heavy-ion collisions. The recent measurement of the J/psi production in Pb-Pb collisi ... More
Presented by Hongyan YANG on 17 Aug 2012 at 17:30
Type: Oral Presentation Session: Parallel 6D: Correlations & Fluctuations (Chair O. Evdokimov)
Track: Correlations and fluctuations
The elliptic flow anisotropies of charged particles and neutral pions (pi0s) have been measured by the CMS collaboration for PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV. The second Fourier components of the anisotropic azimuthal distribution are obtained using an event-plane technique for pi0s and four different analysis techniques for charged particles: event plane, two ... More
Presented by Eric Andrew APPELT on 17 Aug 2012 at 14:20
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The first measurements of the elliptic azimuthal anisotropy of neutral pions, pi0s, produced in 2.76 TeV PbPb collisions will be presented. The results are based on data collected by the CMS experiment during the 2010 LHC running period. The amplitudes of the second Fourier component (v2) of the pi0 azimuthal distributions are extracted using an event-plane technique. The values of v2 are studied ... More
Presented by Monika SHARMA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Heavy quarks, charm and bottom, are produced in early stages of heavy-ion collisions. Propagating through the created matter they serve as a probe of the dynamics of the strongly-interacting, hot and dense plasma of quarks and gluons (QGP). The transverse momentum dependence of the elliptic flow (v2) of heavy quarks is sensitive to the properties of the QGP. A non-zero v2 of low transverse momen ... More
Presented by Denise Aparecida MOREIRA DE GODOY on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Anisotropic flow of identified particles provides important information about the properties of the matter created in a heavy-ion collisions.We report the elliptic flow of strange (K$^0_s$ $\Lambda$) and multi-strange ($\Xi$ $\Omega$) hadrons measured at mid rapidity (|eta|<0.8) in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. The results are compared to measurements at RHIC energies and available ... More
Presented by Carlos PEREZ LARA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Plenary VIB: Flash Talks
Track: Jets
Hot and dense QCD matter, namely the quark gluon plasma, is created in high energy heavy ion collisions. High energy partons are also created through initial hard scatterings and have to traverse the QGP medium. These energetic partons are subject to lose their energy due to strong interactions with the medium. So jets in heavy ion collisions are expected to give information about the stopping pow ... More
Presented by Mr. Yasuki TACHIBANA on 18 Aug 2012 at 10:20
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
NA61/SHINE at the CERN SPS is a fixed-target experiment pursuing a rich physics program including measurements for heavy ion, neutrino and cosmic ray physics. The main goal of the ion program is to explore the most interesting region of the phase diagram of strongly interacting matter. Within the expected (T - mu_B) interval we plan to study the properties of the onset of deconfinement and to s ... More
Presented by Maja Katarzyna MACKOWIAK-PAWLOWSKA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
The study of event-by-event (e-by-e) fluctuations of chemical (particle-type) composition in high-energy nucleus-nucleus collisions is a helpful tool to pin-down the properties of strongly interacting matter. Indeed, according to theoretical calculations, the QCD critical point may be signalled by a characteristic pattern in the measured fluctuations. On the other hand, an incomplete particle ide ... More
Presented by Dr. Anar RUSTAMOV on 16 Aug 2012 at 16:00
Type: Oral Presentation
Presented by Prof. Wolfgang BAUER on 14 Aug 2012 at 19:00
Type: Poster Session: Poster Session Reception
Track: Jets
We investigate the possibility of enhanced jet quenching in the vicinity of the critical temperature similar to the scenario proposed by Liao and Shuryak [PRL 102, 202302(2009)]. We discuss the consequences of the fact that the "shells" of such enhanced, critical quenching grow thinner as a function of the center-of-mass energy sqrt(s) of the collision. A systematic scan of jet quenching as a func ... More
Presented by Prof. Ricardo RODRIGUEZ on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
Possible thermalization mechanism in heavy-ion collisions is explored in classical Yang-Mills(CYM) theory with the initial condition of color-glass condensate with noise varied. We calculate the Lyapunov exponents and show that even a tiny noise triggers instability of the system and then a chaotic behavior sets in as described by the positive Lyapunov exponents, or Kolmogorov-Sinai(K-S) entro ... More
Presented by Hideaki IIDA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The production of heavy quarks is a powerful tool for investigating the dense partonic medium created in high energy heavy ion collisions. Due to their large masses, heavy quarks are mainly produced at the initial stage of the collisions. Therefore the heavy quark probes is sensitive to the full time evolution of the heavy ion collision. The PHENIX experiment measured the strong flow (v_2 ... More
Presented by Dr. Takashi HACHIYA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6B: Exploring the QCD Phase Diagram (Chair K. Rajagopal)
Track: Exploring the QCD phase diagram
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 is one of the main goals of the RHIC Beam Energy Scan(BES). One of the most important observables from high-energy nuclear collisions to study the early evolution of the expanding system is the elliptic flow $v_{2}$. At the top RHIC energy, $\sqrt{s_{N ... More Presented by Shusu SHI on 17 Aug 2012 at 15:20 Type: Poster Session: Poster Session Reception Track: Correlations and fluctuations The large multiplicities at the LHC permit flow harmonics to be determined on an event by event basis in Pb+Pb collisions. We extract these harmonics from inclusive event by event di-hadron correlations, where the minimum track pT is larger than 0.15 GeV. Within a fine centrality bin, we find the correlation function varies substantially on an event by event basis, indicating large fluctuations in ... More Presented by Anthony Robert TIMMINS on 16 Aug 2012 at 16:00 Type: Oral Presentation Session: Parallel 1C: Correlations & Fluctuations (Chair J. Schukraft) Track: Correlations and fluctuations Strong fluctuations of the anisotropic flow and the large acceptance of the ALICE detector allow an efficient selection of the events corresponding to a specific initial geometry. This opens many new possibilities to study the properties of the system created in ultra-relativistic nuclear collisions. In this talk, using the Pb-Pb collisions at$\sqrt{s_{NN}} = 2.76$~TeV data, we demonstrate the ab ... More Presented by Alexandru Florin DOBRIN on 14 Aug 2012 at 15:35 Type: Poster Session: Poster Session Reception Track: Global and collective dynamics To investigate the physics of the strongly interacting system of quarks and gluons under extreme conditions, heavy-ion collision experiments are performed at Large Hadron Collider (LHC) and Relativistic Heavy Ion Collider (RHIC). One of the major discoveries is that elliptic flow v_2 was comparable with an ideal hydrodynamic prediction and, as a result, that a new paradigm of strongly coupled ... More Presented by Koichi MURASE on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Global and collective dynamics Nowadays, relativistic dissipative fluid dynamics is a common tool to describe the space-time evolution of the quark-gluon plasma (QGP) created in ultrarelativistic heavy-ion collisions. The validity of the fluid-dynamical approach is experimentally confirmed by the fact that initial-state anisotropies are directly converted into nonvanishing (event-averaged) Fourier coefficients$\langle v_n ... More
Presented by Dr. Harri NIEMI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We compute the electromagnetic fields generated in heavy-ion collisions by using the HIJING model. Although after averaging over many events only the magnetic field perpendicular to the reaction plane is sizable, we find very strong electric and magnetic fields both parallel and perpendicular to the reaction plane on the event-by-event basis. We study the time evolution and the spatial distributio ... More
Presented by Xu-Guang HUANG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Results on event-by-event fluctuations of the mean transverse momentum of charged particles measured by the ALICE experiment at the LHC are compared to different Monte Carlo approaches. For these studies pp collisions at $\sqrt{s}$~=~0.9, 2.76 and 7~TeV and Pb--Pb collisions at $\sqrt{s_{\rm NN}}$~=~2.76~TeV are used. The analysis is performed within $|\eta| < 0.8$ and $0.15 < p_{\rm T} < 2$~GeV/ ... More
Presented by Stefan Thomas HECKEL on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 7E: New Theoretical Developments (Chair P. Levai)
Track: New theoretical developments
One of the most difficult problems still to be understood is the mechanism of fast thermalization in heavy ion collisions. The problem involves dynamics in strong coupling regime and physics far from equilibrium, therefore is hardly tractable by usual method. The gauge/gravity duality naturally maps the formation of quark gluon plasma to another fundamental problem in black hole physics: informati ... More
Presented by Shu LIN on 17 Aug 2012 at 16:30
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
The strong electromagnetic fields generated in the collision of Pb ions at the LHC allow photon-photon and photonuclear interactions to be studied in a kinematic regime unexplored so far. The exclusive photoproduction of vector mesons was studied with the ALICE detector in ultra-peripheral PbPb collisions, where the impact parameter is larger than the sum of the nuclear radii and hadronic interact ... More
Presented by Christoph MAYER on 16 Aug 2012 at 16:00
Presented by Gunther ROLAND on 13 Aug 2012 at 12:25
Type: Oral Presentation Session: Parallel 7C: New Experimental Developments (Chair T. Peitzmann)
Track: Experiment upgrades, new facilities, and instrumentation
Heavy nuclei probed in deep inelastic scattering and diffraction with leptonic probes in the high-energy (small-x) regime open a new precision window into answering fundamental questions in QCD. The proposed electron-ion collider at BNL (eRHIC) will be a new high-energy and high-luminosity electron-ion/proton machine. The design offers unprecedented access to study the nature of QCD mat ... More
Presented by J.H. LEE on 17 Aug 2012 at 16:50
Type: Oral Presentation Session: Plenary VIB: Flash Talks
Track: Jets
Proton-nucleus (p+A) collisions can be used to investigate cold nuclear matter effects on hard-scattered partons and serve as an important baseline for heavy-ion collisions. In particular, p+A collisions at different centrality selections can probe the impact parameter dependence of nuclear parton distribution functions, initial state energy loss and final state parton interactions in the cold nuc ... More
Presented by Dennis PEREPELITSA on 18 Aug 2012 at 09:30
Presented by Huichao SONG on 13 Aug 2012 at 18:05
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
We investigate the nontrivial correlation between the chiral and deconfinement transition in the two-color QCD. To extract the information, the imaginary chemical potential is taken into account. At $\theta = \pi/2$ where $\theta$ is the imaginary chemical potential divided by the temperature, there is the exact nontrivial center symmetry which is the $Z_2$ symmetry and this symmetry can be spo ... More
Presented by Kouji KASHIWA on 16 Aug 2012 at 16:00
Measurement of correlations of pair of particles with small relative momenta provides insight into geometry and lifetime of particle emitting source in relativistic heavy ion collisions. Kaon femtoscopy extends the range of pair transverse mass covered and provides a sample less affected by decay resonances as compared to pions. The correlation functions of non-identical particles in the three- ... More
Presented by Neha SHAH, neha SHAH on 14 Aug 2012 at 14:35
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
In this work, we propose a new ow correlation observable that provide valuable information about the geometrical properties of the QGP at the thermalization time. An event-by-event analysis within a longitudinal tube initial condition model shows that emitted particles high pt higher than 1 GeV are extremely sensitive to the level of granularity present in the initial conditions. Therefore, ... More
Presented by Philipe MOTA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Interest in the development of the theory of fluctuating hydrodynamics is growing [1]. Early efforts suggested that viscous diffusion broadens the rapidity dependence of transverse momentum correlations [2]. That work stimulated an experimental analysis by STAR [3]. We attack this new data along two fronts. First, we compute STAR’s fluctuation observable using the NeXSPheRIO code, which combines ... More
Presented by Sean GAVIN on 16 Aug 2012 at 16:00
Presented by Vladimir SKOKOV on 17 Aug 2012 at 09:30
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
We report on the new design of a forward electromagnetic calorimeter (FoCal) to be placed in the pseudorapidity region of $2.5 < \eta < 4.5$, which is under consideration as an upgrade of the ALICE experiment at the CERN-LHC. The physics goals of including the calorimeter in the forward direction are to study outstanding fundamental QCD problems at low Bjorken-x values, such as parton distribution ... More
Presented by Taku GUNJI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
One of the fundamental objectives of experiments with ultra-relativistic heavy ions is the study of hadronic matter at high density and high temperature. In this investigation we study in particular the information which can be obtained by analyzing baryonic and mesonic resonances in both hadronic and leptonic decay channels. The decay products of these resonances carry information on the resonanc ... More
Presented by Dr. Sascha VOGEL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
One important theoretical model of heavy ion collisions expects that the collision zone can be divided into two distinct regions: the core and the corona. The corona region is a low density p+p or p+A like region which may be a more favorable for J/psi production as opposed to the hot, dense core. From a Glauber model, this region is found to be symmetric about the reaction plane in Au+Au collis ... More
Presented by Dr. Aneta IORDANOVA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 4D: Pre-Equilibrium & Initial State (Chair T. Ludlam)
Track: Pre-equilibrium and initial state dynamics
The proton gluon distribution function increases rapidly with decreasing x at fixed $Q^{2}$, but cannot increase indefinitely as x goes to 0. Gluon saturation is expected at a low x value when gluon recombination balances gluon splitting. The nuclear (with atomic mass number A) gluon distribution is approximately $A^{1/3}$ larger than the nucleon gluon distribution function at the same x [1]. STAR ... More
Presented by Xuan LI on 15 Aug 2012 at 12:20
The flexibility of RHIC to collide different nuclei provides experiments with a rich resource to systematically test models and scaling behaviors and compare the results to those from Au+Au collisions. For an initial evaluation of the Cu+Au collision system, PHENIX has earmarked several measurements for fast analysis, in particular, forward/backward and central-rapidity J/psi production. These co ... More
Presented by Dr. Richard HOLLIS on 17 Aug 2012 at 16:30
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
A scaling law for the multiplicity distribution in high-energy hadronic collisions has been proposed by Koba, Nielsen, and Olesen (KNO). Experiments at the LHC observed that multiplicities in the central region of proton-proton collisions follow a negative binomial distribution and that they do exhibit KNO scaling. The negative binomial distribution has been theoretically reproduced in the Color G ... More
Presented by Elena PETRESKA on 16 Aug 2012 at 16:00
Traditionally the freeze-out conditions in the heavy-ion collision experiments are obtained by comparing the experimentally measured hadron yields with that from the statistical hadron resonance gas model. In this talk we will present how the freeze-out chemical potentials and the freeze-out temperature can be obtained in a model independent way from ab-initio lattice QCD calculations by utilizing ... More
Presented by Swagato MUKHERJEE on 16 Aug 2012 at 15:20
Type: Poster Session: Poster Session Reception
Track: QCD at finite temperature and density
The medium modifications of vector and axial-vector spectral functions are investigated using Weinberg and QCD sum rules in an attempt to establish chiral symmetry restoration. Such a study is essential for the interpretation of a pertinent signal from dilepton data in heavy-ion collisions. We start from vacuum spectral functions which include both ground- and excited-state resonances for both the ... More
Presented by Paul HOHLER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
We present fully dynamic simulations of central and non-central heavy ion collisions at LHC and at RHIC energies within the perturbative QCD-based partonic transport model BAMPS (Boltzmann Approach to Multi-Parton Scatterings). We focus on the simultaneous investigation of bulk properties, such as elliptic flow, viscosity and thermalization, and of high-pT observables, such as jet quenching. Th ... More
Presented by Oliver FOCHLER on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Plenary VIA: Future Developments II (Chair W. Zajc)
Presented by Harald APPELSHAEUSER on 18 Aug 2012 at 08:55
Type: Oral Presentation Session: Plenary VIA: Future Developments II (Chair W. Zajc)
Presented by jamie NAGLE on 18 Aug 2012 at 08:30
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We explore the relation between proton and nucleon numberfluctuations in the final state in relativistic heavy ion collisions. It is shown that the correlations between the isospins of nucleons in the final state are almost negligible over a wide range of collision energy. This leads to a factorization of the distribution function of the proton, neutron, and their antiparticles in the final state ... More
Presented by Prof. Masayuki ASAKAWA on 16 Aug 2012 at 16:00
We discuss the gluon saturation/color glass condensate effects on J/Psi production in high energy pA and AA collisions. We report the results of numerical calculations of the corresponding nuclear modification factors. We found a good agreement between our calculations and the experimental data on J/Psi production in pA collisions. We also observe that cold nuclear modification effects alone canno ... More
Presented by Kirill TUCHIN on 14 Aug 2012 at 17:45
A remarkable result from heavy ion collisions at the Relativistic Heavy Ion Collider and Large Hadron Collider is that, shortly after the collision event, the quark-gluon plasma produced behaves as a nearly ideal liquid. Understanding the dynamics responsible for such rapid "hydroization" is a challenge using traditional perturbative field theory. In recent years holography has emerged as a po ... More
Presented by Paul CHESLER on 15 Aug 2012 at 10:10
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
HBT measurements are sensitive to the expansion dynamics of the system and they can provide information on the size of the source in space and time at freeze-out (hadron decoupling). Previously, the size of the region of homogeneity has been shown to have an almost linear dependence with particle multiplicity at different beam collision energies. A question of interest is whether the same trend ex ... More
Presented by Alex MWAI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We use the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) to explore HBT/Femtoscopic correlation in proton-proton and heavy ion collisions up to LHC energies. We discuss a) the scaling of HBT radii in proton-proton reactions at top LHC energies and b) the scaling of HBT radii from proton-proton to heavy-ion reactions from RHIC-BES to LHC energies for various systems. [1] G. Graef et al. ... More
Presented by Gunnar GRäF on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
In static picture a quarkonium bound state in deconfined medium is either completely dissociated above some threshold temperature or just stays in the speciﬁc state below the threshold. In contrast, some recent studies suggest that the static quark antiquark potential for describing bound quarkonia should include an imaginary part. This shows a ﬁnite life time of the bound state in the medium ... More
Presented by Mr. Nirupam DUTTA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Heavy-ion experiments at the highest beam energy in the world (Pb-Pb at sqrt(s_NN) = 2.76 TeV) have started in 2010 at the Large Hadron Collider (LHC) at CERN. At the LHC, jet production is more abundant than at RHIC. Jet measurements play a critical role not only for probing the hot and high energy density matter in heavy ion collisions through parton energy loss, but also to observe possible mod ... More
Presented by Daisuke WATANABE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The RHIC physics programs will benefit from developments in hadronic calorimetry. Hadronic calorimetry serves to identify and characterize jets in p+p and A+A collisions and enables studies of the mechanisms of partonic energy dissipation in the medium at high densities and temperatures. The sPHENIX detector concept requires development of a hadronic calorimeter with fairly high sampling fraction ... More
Presented by Dr. Edouard KISTENEV on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
With an effective hadronic chiral flavor SU(3) model we investigate properties of QCD matter for a wide range of temperatures and baryochemical potentials. With our model, including all hadronic resonances up to masses of 2.6 GeV, we show that the strengths of the resonance couplings to the attractive scalar and the repulsive vector fields have a major impact on the order and location of the chira ... More
Presented by Mr. Philip RAU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The PHENIX detector was designed and built at the Relativistic Heavy Ion Collider to explore matter created in collisions of heavy nuclei. PHENIX, as an infrastructure of technologically different systems, has been recording data since 2000. Research results by the PHENIX experiment have already made an impact on the broad field of experimental nuclear physics. Being in its second decade of rese ... More
Presented by Dmitri KOTCHETKOV on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
We study the absorption of hadronic molecules such as the X(3872) by pions and rho mesons during the hadronic stage of heavy ion collisions. We also investigate the possibilities of formation of hadronic molecules during different evolution stages of the hadronic phase. We show that the absorption cross section and its thermal average are strongly dependent on the structure and quantum number of X ... More
Presented by Sungtae CHO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
We analyze hadrochemical freeze-out in central Pb+Pb collisions at CERN SPS energies, employing the hybrid version of the Ultrarelativistic Quantum Molecular Dynamics model, which describes the transition from a hydrodynamic stage to hadrons by the Cooper-Frye mechanism, and matches to a final hadron-resonance cascade. We fit the results both before and after the cascade stage using the Stati ... More
Presented by Francesco BECATTINI, Mr. Tim SCHUSTER on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Student Day B (Chair G. Roland)
Presented by Yen-Jie LEE on 12 Aug 2012 at 14:30
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We show that initial state fluctuations in concert with later-stage hydrodynamic flow describes a range of observables including both even and odd flow harmonics, the ridge, and multiplicity, momentum and flow fluctuations [1]. This is the first comparison between multiplicity and transverse momentum fluctuations and flow fluctuations in the same framework. The simultaneous investigation of these ... More
Presented by George MOSCHELLI on 16 Aug 2012 at 16:00
on 14 Aug 2012 at 12:35
Type: Oral Presentation Session: Plenary IIB: Heavy Flavor (Chair: P. Giubellino)
Presented by Wei XIE on 14 Aug 2012 at 11:15
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Heavy quarks (charm and bottom) are produced early in the collisions and therefore are important probes of the hot and dense matter created in the reactions at RHIC energies. Electrons from semileptonic decays of heavy flavour mesons (so called non-photonic electrons, NPE) are the most feasible tool so far for studying heavy quarks in-medium interactions. NPE azimuthal anisotropy, $v_2$, is of par ... More
Presented by Dr. Daniel KIKOLA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
One of the most promising probes to study deconfined matter created in high energy nuclear collisions 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. In this investigation we study the energy loss for he ... More
Presented by Dr. Sascha VOGEL on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6A: Heavy Flavor & Quarkonia (Chair Y. Akiba)
Track: Heavy flavor and quarkonium production
Heavy quarks serve as valuable probes of the transport properties of the quark-gluon plasma created in relativistic heavy-ion collisions. Within the framework of a Langevin approach, coupled to a realistic 3D hydrodynamic calculation of the medium, we study the heavy quark energy loss due to quasi-elastic multiple scatterings. We extend this algorithm to include medium-induced gluon radiation in h ... More
Presented by Shanshan CAO on 17 Aug 2012 at 15:20
We calculate different types of Wilson loops of temporal size t < 1/T at non-zero temperatures on the lattice using Highly Improved Staggered Quark (HISQ) action and temporal extent Nt=8 and 12. Unlike other static correlators which go around the periodic boundary these Wilson loops are not related to the free energy of static quark anti-quark pair. Therefore from the analysis of the Wi ... More
Presented by Peter PETRECZKY on 14 Aug 2012 at 14:55
Type: Oral Presentation Session: Plenary IIB: Heavy Flavor (Chair: P. Giubellino)
Presented by William HOROWITZ on 14 Aug 2012 at 12:15
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The measurement of single muons from the semi-leptonic decay of D and B mesons is a well-developed method for the study of heavy quark production at forward rapidity. Previous PHENIX results from p+p and Cu+Cu collisions at sqrt(s) = 200 GeV have reported the suppression of heavy quark production in central Cu+Cu collisions at rapidity = 1.65. The measurement of heavy quark production at forward r ... More
Presented by Sanghoon LIM on 16 Aug 2012 at 16:00
Recently, we have proposed a microscopic approach for the quenching and thermalisation of heavy quarks (HQ) in URHIC \cite{Gossiaux:2008,Gossiaux:2009,Gossiaux:2010}, assuming that they interact with light partons through both elastic and radiative processes evaluated by resorting to some parameterization of the running coupling constant, while those partons are spatially distributed along hydro ... More
Presented by Pol GOSSIAUX on 17 Aug 2012 at 17:50
Presented by Tetsuo HATSUDA on 16 Aug 2012 at 11:45
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Heavy charm and bottom quarks provide an important probe of the transport properties of the quark-gluon plasma, created in heavy-ion collisions at the Large Hadron Collider (LHC). They are produced in the early hard collisions and then interact with the hot and dense medium, consisting of light quarks and gluons, undergoing a phase transition to a hot and dense hadron gas. Using a hybrid mode ... More
Presented by Dr. Hendrik VAN HEES on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 2D: Heavy Flavor & Quarkonia (Chair J.-P. Blaizot)
Track: Heavy flavor and quarkonium production
We calculate the yields of quarkonia in heavy ion collisions at RHIC and the LHC as a function of the transverse momentum. We focus on the consistent implementation of dynamically calculated nuclear matter effects, such as coherent power corrections, cold nuclear matter energy loss, and the Cronin effect in the initial state, and collisional dissociation of quarkonia in the final state as they tr ... More
Presented by Dr. Rishi SHARMA on 14 Aug 2012 at 18:05
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
One of the most exciting goals for the field of high-energy nuclear collisions is to understand the phase structure of matter with partonic degrees of freedom especially the transition from hadronic phase to partonic phase, the quark-gluon plasma (QGP). It is believed that the QGP phase dominates the evolution briefly during the early time of the Universe. In high-energy nuclear collisions at RHI ... More
Presented by Prof. Feng LIU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
We discuss a production of direct photons at large transverse momenta p_T in nuclear collisions at different energies and rapidities corresponding to RHIC and LHC experiments. Direct photons are very convenient tool for investigation of nuclear effects since they are not expected to be accompanied by any final state interaction, either energy loss or absorption. Therefore, besides the Cronin enh ... More
Presented by Jan CEPILA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Neutral-pion spectra were measured at midrapidity ($|y|<0.35$) in AuAu collisions at sqrt{sNN} = 39 and 62.4 GeV and compared to earlier measurements at 200 GeV in the $1<p_T<10$ GeV/c transverse-momentum (p_T) range. The nuclear-modification factors (RAA) show significant suppression and a distinct energy dependence at moderate p_T in central collisions. At high p_T, RAA is similar for sqrt ... More
Presented by Norbert NOVITZKY on 16 Aug 2012 at 16:00
Collective flow is one of the key measurements to study the hot and dense matter created in heavy ion collisions, because it relates closely to early evolution of the matter. In particular, higher harmonic flow measurements plays an important role in constraining theoretical model calculations describing properties of the matter. The silicon vertex tracker (VTX) was installed into the PHENIX ... More
Presented by Dr. maki KUROSAWA on 15 Aug 2012 at 09:10
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
The Relativistic Heavy-Ion Collider (RHIC) , at BNL, has started its beam energy scan program by colliding high energy heavy-ions corresponding to baryonic chemical potentials within the range of 20 - 550 MeV. One of the main goals of this beam energy scan program is to locate the critical point which is postulated to lie at the end of the phase transition boundary between partonic ... More
Presented by amal SARKAR on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
To prob e the critical p oint (CP) of QCD phase transition, the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory has undertaken the beam energy scan program, colliding high energy heavy-ions corresponding to baryonic chemical potentials within the range of 20 - 550 MeV. QCD based model calculations reveal that the correlation length of the system diverges at the CP. The ... More
Presented by NIHAR R SAHOO on 16 Aug 2012 at 16:00
Recently formulated model of highly-anisotropic and strongly dissipative hydrodynamics is used in 3+1 dimensions to study behavior of matter produced in ultra-relativistic heavy-ion collisions. We search for possible effects of the initial high anisotropy of pressure on the final soft-hadronic observables. We find that by appropriate adjustment of the initial energy density and/or the initial pseu ... More
Presented by Wojciech FLORKOWSKI, Michael STRICKLAND on 15 Aug 2012 at 08:50
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Quarkonia spectral functions at finite temperature are studied using QCD sum rules in combination with the maximum entropy method. This approach enables us to directly obtain the spectral function from the sum rules, without having to introduce any specific assumption about its functional form [1]. QCD sum rules incorporate finite temperature effects in form of changing values of the v ... More
Presented by Philipp GUBLER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
In this work we study how highly energetic jets affect the hydrodynamic evolution of the quark-gluon plasma in an event-by-event basis. This is done by the introduction of a source term [1] in the energy-momentum conservation equation that describes the evolution of inviscid hydrodynamics (with a realistic equation of state [2]). The source is parametrized in terms of the direction of the jet in ... More
Presented by Rone ANDRADE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Jets propagating through dense matter are modified due to the scattering between the patrons of the jet with the constituents of the medium. Such scattering leads to an exchange of momenta between the medium and the jet, and has components that are both parallel and perpendicular to the direction of jet propagation. These scatterings introduce both drag and diffusion, and also change the rate of p ... More
Presented by Guang-You QIN on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Student Day B (Chair G. Roland)
Presented by Dr. Bjoern SCHENKE on 12 Aug 2012 at 13:30
Presented by Dr. Jean-Yves OLLITRAULT on 13 Aug 2012 at 15:30
Type: Oral Presentation Session: Plenary VIB: Flash Talks
Track: New theoretical developments
We investigate contributions from local hydrodynamic fluctuations to the near side ridge in the two‐particle correlation data from heavy ion collisions. We introduce a local perturbation on top of a hydrodynamic flow which respects conformal symmetry and incorporates radial flow. The subsequent evolution of the perturbation is determined by hydrodynamics; after freeze‐out, we examine the ... More
Presented by Todd SPRINGER on 18 Aug 2012 at 10:30
Type: Oral Presentation Session: Parallel 6D: Correlations & Fluctuations (Chair O. Evdokimov)
Track: Correlations and fluctuations
We describe intrinsic hydrodynamic fluctuations of the expanding boost-invariant (Bjorken) solution. We find that these fluctuations are correlated over a wide rapidity range due to the propagation of the sound modes, whose dispersion is nontrivial because of the expansion. Since the magnitudes of these correlations are proportional to viscosities, their measurement can, in principle, be used ... More
Presented by Prof. Misha STEPHANOV on 17 Aug 2012 at 15:20
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Using hydrodynamics we explore the effects of the initial state, baryon stopping and baryon number transport on various observables such as spectra, elliptic flow and particle yields for heavy ion collisions at beam energies from sqrt{s_{NN}}=7.7 to 200 GeV. We find that observed phenomena such as the centrality dependent freeze out parameters as well as the apparent difference in particle an ... More
Presented by Dr. Jan STEINHEIMER-FROSCHAUER on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 5A: Hadron Thermodynamics and Chemistry (Chair R. Stock)
Identified particle spectra are a basic observable to understand the behaviour of the matter created in high-energy heavy-ion collisions. The transverse momentum distributions of identified hadrons contain informations about the transverse expansion of the system and constrain the freeze-out properties of the matter created. The ALICE experiment has very good particle identification capabilities o ... More
Presented by Leonardo MILANO on 16 Aug 2012 at 14:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Femtoscopic correlations allow one to measure the space-time characteristics of particle production thanks to the effects of quantum statistics for identical particles and final state interactions for both identical and non-identical particles. The main features of the femtoscopy measurements in heavy-ion collisions from SPS to RHIC and LHC are i) the increase of the correlation radii with increa ... More
Presented by Matthew Donald STEINPREIS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Heavy flavor particles, due to their production at the early stages of a collision, are of interest to study the properties of the matter created in heavy ion collisions at RHIC. Previous measurements of $D$ and $B$ mesons at RHIC[1, 2] using semi-leptonic probes show a suppression similar to that of light quarks, which is in contradiction with theoretical models including only a gluon radiative e ... More
Presented by Joseph VANFOSSEN, Jonathan BOUCHET on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 4D: Pre-Equilibrium & Initial State (Chair T. Ludlam)
Track: Pre-equilibrium and initial state dynamics
The precise value of the QGP kinematic shear viscosity eta/s is a question of intense topical interest. Viscous hydrodynamic simulations are a tool for extracting this information from experiment. The key observables are the anisotropic flow coefficients v_n which (i) can be measured very precisely and (ii) are very sensitive to eta/s which controls the "conversion efficiency" v_n/ecc_n for turnin ... More
Presented by Mr. J. Scott MORELAND on 15 Aug 2012 at 11:40
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
We assess the theoretical uncertainties on the inclusive $J/\psi$ production cross section in the Color Evaporation Model using values for the charm quark mass, renormalization and factorization scales obtained from a fit to the charm production data [1]. We use our new results to provide improved baseline comparison calculations at RHIC. We also study the rapidity, $p_T$ and centrality d ... More
Presented by Prof. Ramona VOGT on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
It has been proposed that one signal of the critical point could be a non-­monotonic change in the value of transverse momentum ( $p_t$ ) correlations as a function of centrality and/or incident energy [1]. Accordingly, we present results for two-­particle $p_t$ correlations as a function of event centrality for Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV at ... More
Presented by John NOVAK on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 4C: Electro-Weak Probes (Chair D. D'Enterria)
Track: Electroweak probes
Final data on isolated photon production will be presented, measured in both pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV with the CMS detector at the LHC. The isolated photon transverse energy (ET) spectra, covering the pseudorapidity range |eta| < 1.44 and transverse energy ET > 20 GeV, are found to be in good agreement with next-to-leading-order perturbative QCD ... More
Presented by George STEPHANS on 15 Aug 2012 at 11:20
Type: Oral Presentation Session: Parallel 2B: Jets (Chair P. Jacobs)
Track: Jets
Measurements of charged hadron and inclusive jet transverse momentum (pT) spectra in pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV with the CMS detector will be reported. These measurements make use of the high-statistics jet-triggered data recorded in 2011, including the total available PbPb luminosity of 150/ub. Charged particles are reconstructed using an iterati ... More
Presented by Marguerite Belt TONJES on 14 Aug 2012 at 17:25
Type: Oral Presentation Session: Parallel 2B: Jets (Chair P. Jacobs)
Measurements of high-pt particle production in heavy-ion collisions at RHIC have shown that medium-induced energy loss affects the partons produced in the early stage of a heavy-ion collision. The increased initial production cross section for partons at LHC energies makes fully reconstruted jets available in a wide kinematic range, which allows for a differential investigation of parton energy l ... More
Presented by Rosi Jan REED on 14 Aug 2012 at 18:05
Type: Oral Presentation Session: Parallel 6B: Exploring the QCD Phase Diagram (Chair K. Rajagopal)
Track: Exploring the QCD phase diagram
Hydrodynamic fluctuations are inherent in any small space-time varying system. They may be significantly impacted by the presence of a critical point in the QCD equation of state during the expansion phase of a heavy ion collision. Simple models are studied to gain insight into the essential physics. This study suggests which observables are most sensitive to a critical point, although much more ... More
Presented by Joseph KAPUSTA on 17 Aug 2012 at 14:40
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Strong jet quenching and high-pT hadron suppression as observed in relativistic heavy-ion collisions are striking experimental signatures for the formation of a deconfined QCD plasma, in which partons suffer from medium-induced energy loss. In particular, heavy quarks represent key probes for revealing the properties of the produced matter. In this talk, we discuss the consequences of a realist ... More
Presented by Dr. Marlene NAHRGANG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
In order to get information about the characteristics of the medium produced in high-energy heavy-ion collisions using reconstructed jets, the effect of background subtraction has to be well under control. In this study, we address this issue by embedding jets in a heavy-ion event and then considering the influence of the subtraction method and of different backgrounds, characterized by different ... More
Presented by Liliana APOLINáRIO on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6E: Initial State and p-A (Chair E. Wang)
Track: Electroweak probes
Thermal emission of photons from relativistic heavy ion collisions is believed to have a very strong temperature dependence and the high p_T thermal photons are expected to provide a glimpse of the early part of the expansion history when the system is still in the plasma phase. Photons having p_T > 1 GeV/c are thus specially suitable for probing fluctuations in the initial QCD matter density dist ... More
Presented by Dr. Rupa CHATTERJEE on 17 Aug 2012 at 15:40
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
One of the most promising probes to study deconfined matter created in high energy nuclear collisions is the energy loss of (heavy) quarks. Theoretically however there exist various ambiguities, which still need to be resolved. In this work we investigate the dependence on the medium description of heavy quark energy loss. We find that by only changing the theoretical medium description and keepin ... More
Presented by Dr. Sascha VOGEL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
Recently there has been much discussed the appearance of inhomogeneous chiral phases in the vicinity of the chiral restoration [1,2]. The critical end point should be the Lifshitz point, which properties have not been explored so much.Here we discuss an implication of inhomogeneous phase on cooling of hybrid stars. We consider the dual-chiral-density-wave (DCDW) specified by the spatially modulat ... More
Presented by Prof. Toshitaka TATSUMI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
The initial conditions play a fundamental role in the fluid-dynamical modeling of the quark-gluon plasma (QGP) created in ultrarelativistic heavy-ion collisions. Many observables that are important in determining the properties of the QGP, such as elliptic flow (v2) and triangular flow (v3), appear to be generated mainly from the initial geometry of the energy density profile. Since the initial ... More
Presented by Ioannis BOURAS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The hydrodynamic behavior of the strongly interacting Quark-Gluon Plasma (QGP) has mostly been studied at mid-rapidity and important additional constraints on the longitudinal expansion of the medium are needed, in particular to help in constraining the initial state. The forward rapidity bulk medium initial state is also sensitive to low-x partons in one nucleus and high-x partons in the other. ... More
Presented by Dr. Cesar L. for the PHENIX Collaboration SILVA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3A: Global & Collective Dynamics (Chair T. Kodama)
Track: Global and collective dynamics
We present recent developments in describing anisotropic flow in heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory and the Large Hadron Collider (LHC) at CERN with a relativistic 3+1 dimensional viscous event-by-event hydrodynamic simulation. We present results for elliptic, triangular and higher harmonic flow coefficients, including comparisons ... More
Presented by Bjoern SCHENKE on 15 Aug 2012 at 08:50
Presented by Kevin DUSLING on 13 Aug 2012 at 14:40
I study the properties of the Euclidean Dirac equation for a light fermion in the presence of both a constant abelian magnetic field and an SU(2) instanton. In particular, I analyze the zero modes analytically in various limits, both on R^4 and on the four-torus, in order to compare with recent lattice QCD results, and study the implications for the electric dipole moment of the instanton induced ... More
Presented by Gokce BASAR on 17 Aug 2012 at 17:30
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
A very intense magnetic field is expected in non-central nucleus-nucleus collisions, and to reach ~ 10^14 T at the LHC energies. Not only being the strongest magnetic field in the Universe (cf. ~ 10^11 T on the surface of magnetars), various consequences of physics interests are in discussion, including chiral magnetic effects, synchrotron radiation, and non-linear behaviors of QED e.g. photon sp ... More
Presented by Kenta SHIGAKI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Triggered di-hadron correlation studies using Au+Au collisions at #sqrt(S_{NN}) = 200GeV in STAR revealed a novel “ridge-like” structure in two dimensions (#Delta#eta, #Delta#phi) [1] for high p_{T} particles. Similar structure was also present in an inclusive un-triggered di-hadron correlation analysis [2]. We study the <p_{T}> evolution of un-triggered analysis by increasing the lower p_{T} ... More
Presented by Mr. L. Chanaka DE SILVA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
Quark matter is expected in the core region of neutron stars because of the central density is sufficiently high for nucleons to dissolve into quarks. The compact stars consist of not only nuclear matter but also hypeons and quarks, we call such stars "hybrid stars". However, the equation of state (EOS) is still not clear and many theoretical studies try to elucidate the EOS in the high density a ... More
Presented by Prof. Tomoki ENDO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The STAR results [1] from dihadron correlations as a function of the high-pt trigger azimuth relative to the event plane (phi_s) show a significant change from in-plane (phi_s~0) to out-of-plane direction (phi_s~90 degree). The near-side correlation is composed of two components: the jet-like correlation and the ridge; The former is found to be invariant over phi_s while the ridge is primarily obs ... More
Presented by Joshua KONZER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
Photons are of great interest in relativistic heavy-ion collisions due to the fact that they do not interact strongly, and thus are used to make a tomographic view of those collisions. Of special interest are the directly produced high-transverse momentum photons. The ratio of their yield in Pb-Pb to pp collisions is sensitive to initial state effects. Furthermore, direct photons can be u ... More
Presented by Mauro Rogerio COSENTINO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
The Relativistic Heavy Ion Collider (RHIC) is built to search for the Quark-gluon Plasma (QGP) and to study its properties in laboratory through high energy heavy-ion collisions. J/$\psi$ suppression in heavy-ion collisions due to color screening of quark and anti-quark has been proposed as a signature of QGP formation. But other mechanisms are likely to contribute to the observed J/$\psi$ in heav ... More
Presented by Wangmei ZHA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
We study charmonium physics in heavy-ion collisions within the framework of the non-equilibrium transport model UrQMD at SPS, RHIC and LHC energies. For pp collisions at LHC energies we find a considerable J/Psi suppression in dependence of the particle multiplicity.
Presented by Thomas LANG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
J/psi measurements can be performed with ALICE through the dilepton decay into electrons (for rapidity |y|<0.9) and muons (for rapidity -4.0<y<-2.5) pairs, in proton-proton, proton-nucleus and nucleus-nucleus collisions. J/psi measurements are very important in Pb-Pb as a probe of the Quark Gluon Plasma (QGP), in order to study mechanisms of suppression or regeneration. Proton-proton collisions ar ... More
Presented by Marcel ARAUJO SILVA FIGUEREDO on 16 Aug 2012 at 16:00
The hot and dense nuclear matter created in nuclear collisions at relativistic energies consists of a plasma of deconfined quarks and gluons. Due to their large mass, the charm quarks are mainly formed in the first instants of the nuclear collision and will consequently experience the full history of the system. It was predicted that the strongly bound J/Ã state will be suppressed in the hot and ... More
Presented by Ionut Cristian ARSENE on 14 Aug 2012 at 17:25
on 14 Aug 2012 at 10:30
Type: Poster Session: Poster Session Reception
Track: Jets
The first stage of the sPHENIX upgrade focuses on the measurement of jet observables at RHIC energies. The enhanced acceptance and high rate capabilities of this upgrade allow for the measurement of a large set of jet observables, including dijet and gamma-jet properties, across a large kinematic range. The sensitivity of the proposed upgrade to the medium modification of such observables and the ... More
Presented by Dr. J. Ali HANKS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The AdS/CFT correspondence has been widely used to study the jet quenching of hard probes traveling in the strongly-coupled plasma. Nevertheless, in most of studies, the hard probes were assumed to be created at the late time within the thermalized medium. To understand the thermalization of the medium and its influence on high-energy probes generated in the early time in the strongly-coupled scen ... More
Presented by Di-Lun YANG on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3B: Jets (Chair S. Mioduszewski)
The recent measurements of jet suppression at LHC indicate a presence of "jet quenching" -- strong energy loss of energetic jets in hot and dense QCD medium which has been already observed at RHIC experiments. We present a measurement of jet properties which sheds more light on the mechanism of jet energy loss. We will discuss the results of measurement of longitudinal, and transverse structure of ... More
Presented by Martin RYBAR on 15 Aug 2012 at 09:30
Type: Oral Presentation Session: Parallel 3B: Jets (Chair S. Mioduszewski)
Track: Jets
The jet fragmentation function of inclusive jets with pT > 100 GeV/c in PbPb collisions is measured for reconstructed charged particles with pT > 1 GeV/c within the jet cone. A data sample of PbPb collisions collected in 2011 at a center of mass energy of √sNN =2.76 TeV corresponding to an integrated luminosity of Lint = 129 μb−1 is used. The results for PbPb collisions as a function of colli ... More
Presented by Frank MA on 15 Aug 2012 at 09:50
Type: Poster Session: Poster Session Reception
Track: Jets
Collimated sprays of particles associated with hard partons, jets, are an important tool in testing QCD and probing the hot and dense nuclear matter created in high energy heavy-ion collisions. Jets enable to study hard scattering, fragmentation and hadronisation and their modification in presence of a partonic medium with respect to baseline vacuum measurements with proton-proton collisions. We ... More
Presented by Michal VAJZER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The poster presents the jet response and inclusive pT spectra of jets reconstructed in PbPb collisions with the CMS detector at a center-of-mass energy of 2.76 TeV. The jets are found and reconstructed using both the calorimeters and the tracker system, through iterative cone and anti-kT algorithms, separately. The high-pT jet triggers and their efficiencies are studied for both PbPb and pp collis ... More
Presented by Ying LU on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3D: Pre-Equilibrium & Initial State (Chair K. Eskola)
Track: Jets
Parton energy loss in the hot QCD medium will manifest itself not only in leading hadron spectra but also in reconstructed jet productions in high-energy nucleus-nucleus collisions. With its more differential power full jets in heavy-ion collisions can then provide excellent tools to study the properties of the QGP and impose constraints on different parton energy loss models. With this motivat ... More
Presented by Prof. Ben-Wei ZHANG on 15 Aug 2012 at 09:50
Type: Oral Presentation Session: Plenary VIB: Flash Talks
Track: Heavy flavor and quarkonium production
The flavor dependence of jet quenching is a powerful handle to discriminate models of parton energy loss in heavy ion collisions. While there is evidence for a strong energy loss of heavy quarks from single particle measurements, heavy flavor tagging of fully reconstructed jets has thus far not been achieved in heavy ion collisions. In this talk we demonstrate the capacity of CMS to identify jets ... More
Presented by Jorge A ROBLES on 18 Aug 2012 at 09:50
Type: Oral Presentation Session: Plenary VIB: Flash Talks
Track: Jets
The poster presents jet shapes, defined as the fractional transverse momentum distribution as a function of the distance r from the jet axis, where the jets are reconstructed by the anti-kT clustering algorithm. We determine the energy flow inside the jet by using particles reconstructed and calibrated using the Particle Flow algorithm. Different background subtraction methods are employed to subt ... More
Presented by Ms. Yaxian MAO on 18 Aug 2012 at 09:40
Type: Oral Presentation Session: Parallel 3B: Jets (Chair S. Mioduszewski)
Track: Jets
Jet shape measurements are important for many applications. When measured in pp collisions they can be used to constrain generator and showering settings. When measured in PbPb collisions they can be used to probe for distortions from energy loss in the hot and dense medium. Fully unfolded jet shape measurements will be presented and compared with generator expectations in 7 TeV pp collisions, cor ... More
Presented by Pelin KURT on 15 Aug 2012 at 09:10
Type: Oral Presentation Session: Parallel 3B: Jets (Chair S. Mioduszewski)
To capture the full dynamics of the mechanisms of energy loss of hard partons in their passage through the dense medium created in Heavy Ion Collisions, jet reconstruction is required. In this analysis we explore the radiation pattern of jets in Pb–Pb collisions at sqrt(s_NN) = 2.76 TeV and compare it to that of baseline pp jets at the same collision energy. Di-jets are selected by requiring a ... More
Presented by Leticia CUNQUEIRO on 15 Aug 2012 at 08:50
Type: Poster Session: Poster Session Reception
Track: Jets
In heavy-ion collisions, jet properties are expected to be modified by the interaction with the hot and dense medium. The modification is strongly related with properties of hot and dense matter and the study of jet properties is a versatile probe for the properties of the QGP. However, in heavy-ion collisions it is difficult to recover the jet quenching effects at small particle momentum due to ... More
Presented by Dosatsu SAKATA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3C: Electro-Weak Probes (Chair J. Kapusta)
We investigate the correlations of photons produced by back scattering of fast partons in quark gluon plasma  with their away‐side jets. Back scattering with photon emission, or jet‐photon conversion,  was originally proposed as a novel source of photons in Phys. Rev. Lett. 90, 132301 (2003).  The unique appeal of this photon source lies  ... More
Presented by Prof. Rainer FRIES on 15 Aug 2012 at 09:30
Type: Oral Presentation Session: Parallel 4B: Jets (Chair N. Armesto)
Previous experimental measurements from nuclear collisions have indicated modifications of jets by interaction with the medium created in the collision. Observables from particle correlations in the ALICE detector continue to provide access to key properties of the hot deconfined nuclear matter. New results from two- and three-particle number and transverse momentum correlations are presented. Sp ... More
Presented by Jason Glyndwr ULERY on 15 Aug 2012 at 11:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Different from the Jpsi yield which is almost identical at SPS, RHIC and LHC energies, the Jpsi transverse momentum distribution is sensitive to the nature of the medium and can be used to probe the quark-gluon plasma formation in heavy ion collisions. We calculated in a detailed transport approach the nuclear modification factor as a function of transverse momentum, the averaged transverse moment ... More
Presented by Pengfei ZHUANG on 16 Aug 2012 at 16:00
ALICE is the LHC experiment dedicated to the study of heavy ion collisions. The main purpose of ALICE is to investigate the properties of a new state of deconfined nuclear matter, the Quark Gluon Plasma. Quarkonium measurements will play a crucial role in this investigation. In particular, the sequential suppression of the quarkonium states by color screening has long being suggested as a signatur ... More
Presented by Roberta ARNALDI on 14 Aug 2012 at 14:35
Type: Poster Session: Poster Session Reception
Track: Jets
We address a recent puzzling result from the LHC: the jet fragmentation functions measured in $PbPb$ and $pp$ collisions appear very similar in spite of a large medium-induced energy loss (we will call this jet fragmentation scaling", JFS). To model the real-time non-perturbative effects in the propagation of a high energy jet through the strongly coupled QCD matter, we adopt an effective dime ... More
Presented by Frasher LOSHAJ on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Angular correlations with respect to a back-to-back trigger pair of high-p_T hadrons with similar momenta (above 4 GeV/c) have shown no differences between d+Au and Au+Au collisions suggesting tangential emission of selected di-jets. In this talk we increase the p_T threshold of the leading hadron in the pair (8, 10 and 12 GeV/c) to vary the degree of the surface bias. The di-jet energy imbalance ... More
Presented by Hua PEI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We study Lambda-Lambda correlation in high-energy heavy-ion collisions based on the Lambda-Lambda interactions proposed so far. Lambda-Lambda interaction and the existence of H-dibaryon are long-standing problems in hadron physics. Since high-energy heavy-ion collisions at RHIC and LHC can be utilized as the exotic hadron factories [1], they would also provide information on exotic interactions su ... More
Presented by Akira OHNISHI on 16 Aug 2012 at 16:00
The measurement of heavy-flavour production provides insights on the properties of the high-density QCD medium created in heavy-ion collisions. In particular, the comparison of charm production in pp and in Pb-Pb collisions allows to study the mechanism of in-medium energy loss of heavy quarks. Furthermore, since strange quarks are abundant in the medium, the relative yield of D+s mesons with res ... More
Presented by Gian Michele INNOCENTI on 15 Aug 2012 at 12:20
Type: Oral Presentation Session: Parallel 5B: QCD at Finite Temperature and Density (Chair F. Karsch)
Track: QCD at finite temperature and density
We present our estimate for the charm quark's contribution to the equation of state and to the fluctuations of conserved charges. Our results are based on simulations with dynamical charm at physical quark masses. We also address the question, to what extent staggered simulations are reliable. We give comparisons with the Wilson formulation as well as with results using dynamical overlap ferm ... More
Presented by Dr. Claudia RATTI on 16 Aug 2012 at 15:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
In the dense and high-temperature systems formed in relativistic heavy-ion collisions, final-state composites - light nuclei and antinuclei - are formed close to the freeze-out hypersurface. Their spectra, compared to those of the constituent (anti)nucleons, can be described by picturing the formation process as the coalescence of a number of nucleons that are close to each other in phase spa ... More
Presented by W.J. LLOPE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Multiple parton interactions are expected to produce large long-range multiplicity correlations in high energy proton-proton and nucleus-nucleus collisions. Color glass condensate models explain the long range forward-backward (F-B) correlations by introducing strong color fields extended longitudinally in rapidity. Clustering of color sources also leads to F-B correlations. The measurement of the ... More
Presented by Sudipan DE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
An enhancement of low-mass di-electron production which is compared to expected yields from known hadron sources was observed by the CERES experiment at CERN SPS in 158 A GeV central Pb+Au collisions (sqrt(s)=17.3GeV). More recently, NA60 reported their di-muon measurements in 158 A GeV In+In collisions. The enhancement of di-muon at $M_{\mu\mu} < 1$ GeV/$c^{2}$ can be described by a broadened s ... More
Presented by Dr. Huang BINGCHU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
Luminosity is an essential ingredient for the measurement of the cross section of physical processes. Luminosity determination in ALICE at the LHC is based on the visible cross sections measured in dedicated calibration experiments (van der Meer scans). Besides serving as reference for the determination of integrated luminosities, the cross sections measured in van der Meer scans can, with suitab ... More
Presented by Emilia LEOGRANDE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
Confinement phenomenon for a long time was associated with Bose-Einstein condensation (BEC) of cirtain magnetic objects. In a series of previous works we had shown that it is indeed the case for lattice monopoles, which in pure gauge theory are about as numeroous near $T_c$ as gluons. We can now show that with increasing number of quark flavors to $N_f\sim 10$ the deconfinement transition mo ... More
Presented by Edward SHURYAK on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6D: Correlations & Fluctuations (Chair O. Evdokimov)
Track: Correlations and fluctuations
Presented by Sooraj Krishnan RADHAKRISHNAN on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 5D: New Theoretical Developments (Chair B. Sinha)
Track: QCD at finite temperature and density
An effective theory for the region near the critical temperature, the "semi"-QGP, has been developed. In QCD, this is dominated by the partial ionization of color, up to temperatures about 300 MeV. Using the effective model, the temperature dependence for the ratio of the shear viscosity, to the entropy, is computed. This predicts a sharp increase in this ratio between ~ 160 MeV and ~ 300 MeV.
Presented by Dr. Robert PISARSKI on 16 Aug 2012 at 15:40
The major long-term goal of the ALICE experiment at the LHC is to provide precision measurements of the properties of the Quark-Gluon Plasma, the state of deconfined matter produced in high-energy heavy-ion collisions. Experiments towards the characterisation of strongly interacting matter at high density will need to focus on rare probes and the study of their collective properties and hadronizat ... More
Presented by Roy Crawford LEMMON on 17 Aug 2012 at 15:20
Type: Oral Presentation Session: Parallel 6C: New Experimental Developments (Chair J. Stroth)
Track: Experiment upgrades, new facilities, and instrumentation
The Compressed Baryonic Matter (CBM) Experiment will explore the phase diagram of strongly interacting matter in the region of high net baryon densities. The experiment is laid out to process nuclear collisions at rates up to 10 MHz, the highest in the field. A unique wide spectrum of observables will be accessible, including rarest probes like hadrons containing charm quarks, or multi-strange hyp ... More
Presented by Johann HEUSER on 17 Aug 2012 at 15:40
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
We employ a grid based stochastic technique to solve the on-shell Boltzmann transport equation including inelastic 3<->2 processes. The case of an interacting massless partonic gas in a longitudinally expanding Bjorken geometry is considered. The numerical accuracy of the algorithm is first rigorously established from comparisons to both static box calculations and earlier results from the MPC ... More
Presented by Mr. Dustin HEMPHILL on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: New theoretical developments
One of the main discoveries at RHIC is the strongly coupled quark-gluon plasma (sQGP), based particularly on the observed "perfect fluid" and strong jet quenching. One of the most interesting physics to see at LHC is whether and how such sQGP properties will change. Based on the deep and generic electric-magnetic duality, we've suggested that the QCD plasma contains the quarks and gluons (color-el ... More
Presented by Jinfeng LIAO on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
We investigate the impact of interactions in the hadron resonance gas (HRG) modelled by a volume assigned to the hadrons in a thermodynamically consistent way. We discuss the influence of the hadron radius, a parameter of the model, on thermodynamic quantities as energy density, entropy density and pressure. The consideration of interactions is followed by us arguing that the commonly used free ... More
Presented by Michael WINN on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 7C: New Experimental Developments (Chair T. Peitzmann)
Track: Experiment upgrades, new facilities, and instrumentation
The project of a new experimental facility at CERN, the Large Hadron-electron Collider, which will collide electrons against the LHC beams at center-of-mass energies around 1 TeV per nucleon, will be presented. After a brief introduction and showing the proposals for accelerator and detector, the physics opportunities for QCD studies will be discussed. Specifically, I will focus on the possibiliti ... More
Presented by Anna STASTO on 17 Aug 2012 at 17:10
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The Compressed Baryonic Matter Experiment (CBM) is one of the core experiments of the future FAIR facility at Darmstadt/Germany. The experiment will explore the phase diagram of hadronic matter in the regime of highest baryon densities. Nuclear fireballs created in heavy ion collisions of 8-45 AGeV beam energy will be studied with numerous probes, among them open charm. Reconstructing those rare ... More
Presented by Tobias TISCHLER on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6E: Initial State and p-A (Chair E. Wang)
Recently, by performing the complete next-to-leading order calculation, we have demonstrated the one-loop factorization for inclusive hadron productions in pA collisions in the saturation formalism. The differential cross section is written into a factorization form in the coordinate space at the next-to-leading order, while the naive form of the convolution in the transverse momentum space does ... More
Presented by Dr. Bowen XIAO on 17 Aug 2012 at 15:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Two Forward Silicon Vertex Trackers (FVTX) have been installed at the PHENIX Experiment at RHIC, and extend the precision vertex capability of the PHENIX Silicon Vertex Trackers (VTX) to forward rapidity. The FVTX consists of two endcaps, with four silicon mini-strip planes each, covering the angles from ~10 to 35 degrees (1.2< |y|<2.2) that match the two existing PHENIX muon spectrometer arms. E ... More
Presented by J. Matthew DURHAM on 16 Aug 2012 at 16:00
The physics of the Quark-Gluon Plasma (QGP), currently explored experimentally in heavy-ion collisions, is non-perturbative for temperatures below approximately 1 GeV. One of the fundamental properties of the QGP, the Equation of State, is a subject of extensive studies in lattice QCD. The lattice QCD Equation of State is now an essential requirement for the correct hydrodynamic modeling of heavy- ... More
Presented by Alexei BAZAVOV on 16 Aug 2012 at 15:40
Type: Oral Presentation Session: Student's Day A (Chair S. Bass)
Presented by Prof. Misha STEPHANOV on 12 Aug 2012 at 09:00
Many recent lattice QCD calculations predict that there may be a first order phase transition from hadronic matter to a Quark-Gluon Plasma that ends in a critical point, with a continuous phase transition on the other side of the critical point. The Relativistic Heavy Ion Collider (RHIC) has conducted a program to probe different regions of the QCD phase diagram in the vicinity of the possible cri ... More
Presented by Jeffery MITCHELL on 17 Aug 2012 at 16:30
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The Compressed Baryonic Matter experiment, CBM, is being built at the Facility for Antiproton and Ion Research, FAIR, at Darmstadt. The goal is to investigate the QCD phase diagram in particular in the region of high net baryonic density, using heavy ion collisions in a fixed target experiment at beam energies ranging from 8 to 45 GeV/nucleon. The high beam intensity and -quality of the SIS300 acc ... More
Presented by Jan KOPFER on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
The PHENIX Experiment is planning a major upgrade to enhance its capabilities to measure jets in heavy ion collisions, as well as in p+A, polarized proton, and eventually e-A collisions at the Electron Ion Collider. One of the major new components of this upgrade will be a new compact electromagnetic calorimeter covering ±1 units in pseudorapidity and 2 in phi. It will consist of a matrix of t ... More
Presented by Dr. Craig WOODY on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The effect of initial fluctuations on partonic jet energy loss in a hydrodynamical background in high-energy heavy-ion collisions is studied within a next-to-leading order (NLO) perturbative QCD parton model. An energetic parton jet is found to lose more energy loss with fluctuating initial conditions than that with smooth initial conditions due to initial dominative positive correlation between ... More
Presented by Dr. Hanzhong ZHANG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
In heavy-ion collisions, measurement of azimuthal anisotropy in emitted particle momentum distribution is a one of the important themes for the investigation of Quark Gluon Plasma (QGP). For this measurements, we need to be able to measure the reference reaction/event planes direction with good accuracy. In 2011 the Silicon Vertex detector (VTX) was installed in the RHIC-PHENIX experiment. Th ... More
Presented by Mr. Hiroshi NAKAGOMI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
Over the last decade, there has been a plethora of new and exciting results in heavy-ion collisions emanating from the CERN and Brookhaven Laboratories. These results have led to a sea change of the view on how the evolution of a high energy heavy-ion collision proceeds. What has become apparent is that in order to validate claims of perfect fluidity, for example, the initial conditions at small ... More
Presented by Matthew LAMONT on 16 Aug 2012 at 16:00
The past decade of heavy ion physics at RHIC has produced many surprising discoveries and puzzles. Currently the experiments at the LHC are providing a first look at things to come: a burgeoning program for studying the Quark Gluon Plasma with reconstructed jets. The PHENIX collaboration is in the process of developing a long term plan involving a series of aggressive upgrades designed to exp ... More
Presented by John HAGGERTY on 17 Aug 2012 at 14:20
During 12 years of operations, PHENIX has discovered a strongly coupled QGP and studied many of its basic properties, examined effects in cold nuclear matter, measured the gluon helicity structure of the proton, and probed the proton transverse spin structure. PHENIX is planning a large upgrade for the next decade, sPHENIX, to answer many of the questions spurred by our discoveries during the last ... More
Presented by Joseph SEELE on 17 Aug 2012 at 15:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We report results from a new study of lattice QCD with decreased lattice spacing and using two flavours of light dyanamical quarks at finite temperature and chemical potential through the method of Taylor series expansions. With a factor of two in lattice spacings covered to date, the approach to the continuum limit is controlled better. In units of the inverse Compton wavelength of the light pion ... More
Presented by Sourendu GUPTA on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 4D: Pre-Equilibrium & Initial State (Chair T. Ludlam)
Track: Pre-equilibrium and initial state dynamics
We outline significant recent progress in a program to include quantum corrections to the evolution of the classical color fields produced in high-energy ultra-relativistic heavy ion collisions. Previous work in this direction for a scalar \phi^4 theory [1] has now been extended to QCD. Leading contributions from unstable quantum modes can be resumed to all loop orders and expressed in terms of a ... More
Presented by Raju VENUGOPALAN on 15 Aug 2012 at 12:00
Type: Oral Presentation Session: Parallel 5A: Hadron Thermodynamics and Chemistry (Chair R. Stock)
We investigate, using the newest LHC data, the energy dependence of hadron production within the framework of the statistical hadronization model. The data are confronted with predictions based on extrapolation from lower (RHIC) energies. While the yields of hadrons made from light (u,d,s) quarks generally exhibit little change apart from the overall increase in multiplicity, a characterist ... More
Presented by Peter BRAUN-MUNZINGER on 16 Aug 2012 at 14:20
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
We have discussed the tunnelling effect in FL model. The tunnelling coefficient is derived in the field configuration space by calculating the transition amplitude using the path integral at SPA and the dilute instanton gas approximation. By studying the tunnelling effect between the two degenerating vacuums at the critical temperature and chemical potential, we find that the system could be ... More
Presented by Dr. Song SHU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: New theoretical developments
ALICE, ATLAS and CMS detectors at LHC and previously PHENIX and STAR detectors at RHIC have provided compelling evidence for higher order flow components apart from the elliptic flow v2. It is by now well established that both RHIC and LHC have produced a ”perfect fluid” of Quark Gluon Plasma with eta/s close to zero, as predicted by AdS/CFT limit. One expects that higher order harmonics an ... More
Presented by Bikash SINHA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
Asymmetric high-energy proton-nucleus collision can give unique test of the high-energy nuclear effects. This case nuclear modification and rapidity asymmetry can be describe in parallel [1]. Moreover, measurements might enable us to separate or at least understand better the the mechanisms of the final and initial state nuclear effects in nucleus-nucleus collisions. Predictions for nuclear eff ... More
Presented by Gergely BARNAFOLDI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Plenary IIA: Jets (Chair M. Gyulassy)
Presented by Guilherme TEIXEIRA DE ALMEIDA MILHANO on 14 Aug 2012 at 08:30
Type: Poster Session: Poster Session Reception
Track: Jets
We generalize the percolating transition discovered in [1] to the full phase diagram, exploring the onset of "quarkyonic percolation" for SU(N) Yang-Mills matter when baryon density, temperature and number of colors are varied. We show that percolation's dependence on number of colors is different from deconfinement, suggesting that the two phases are generally distinct, with the percolating pha ... More
Presented by Giorgio TORRIERI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
Photons are believed to be clean and penetrating probes of the medium created in ultra-relativistic heavy-ion collisions. The thermal photon spectra and their anisotropy are known to be very sensitive to the thermalization time, the specific shear viscosity, the equation of state of produced matter, and the initial state fluctuations [1]. Previous computations of photon emission spectra have been ... More
Presented by Chun SHEN on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
The hot and dense fireball produced in high energy heavy ion collisions, such as that at RHIC, exhibits complicated dynamics and time evolution. Thermal photons have a negligible cross-section with the medium and so pass through unmodified, thus measuring their properties gives access to the entire time evolution of the fireball. Thermal photons are expected to be observable at low momentum. The ... More
Presented by Richard PETTI on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3C: Electro-Weak Probes (Chair J. Kapusta)
Track: Electroweak probes
The penetrating nature of dileptons makes them suitable probes to explore the properties of the strongly-interacting medium created in relativistic nuclear collisions. This study investigates thermal dilepton production using MUSIC (a Monotone Upstream-centered Scheme for Ion Collisions): a 3+1D hydrodynamic simulation with or without shear viscosity. We utilize dilepton emission rates that are ... More
Presented by Gojko VUJANOVIC on 15 Aug 2012 at 08:30
Type: Poster Session: Poster Session Reception
Track: QCD at finite temperature and density
I will review recent and ongoing work on thermal meson properties relevant for the hadron gas regime in Relativistic Heavy Ion Collisions. These include transport coefficients, chemical nonequilibrium, susceptibilities, isospin breaking and different aspects on chiral symmetry restoration and the QCD transition. The basic framework is the use of Chiral Effective Lagrangians which ensure the model ... More
Presented by Prof. Angel GOMEZ NICOLA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
While experimentally very demanding, thermal (low pT) photons and dileptons offer unique, direct access to the medium formed in heavy ion collisions, its size, temperature, lifetime, viscosity and other properties. Higher pT jet-medium photons can serve as a control (complementary) probe. On the other hand these measurements are very involved and the interpretation of the results is challenging. ... More
Presented by Dr. Gabor DAVID on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
We calculate explicitly the thermal quark propagator in presence of magnetic field that is relevant for heavy ion collision experiments at RHIC and LHC. Using this propagator, we calculate the momentum dependent polarization tensor and discuss the relevant collective excitations. Using the same, we also evaluate the thermal photon rate of quark matter in presence of magnetic field. We estimate the ... More
Presented by Dr. Bhaswar CHATTERJEE on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 6E: Initial State and p-A (Chair E. Wang)
Track: New theoretical developments
We report on a recently proposed scenario for thermalization of hot QCD matter after the "Little Bang" in heavy ion collisions. A distinctive feature of the pre-equilibrium system (the Glasma) is the high over-population of phase space for gluons, which we argue plays a central role for the thermalization of the Quark-Gluon Plasma. In particular, the over-population (1) coherently amplifies scatte ... More
Presented by Jinfeng LIAO on 17 Aug 2012 at 14:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
We investigate theta-vacuum effects on the QCD phase diagram for the realistic 2+1 ﬂavor system, using the three-ﬂavor Polyakov-extended Nambu-Jona-Lasinio (PNJL) model and the entanglement PNJL model as an extension of the PNJL model. The theta-vacuum effects make the chiral transition sharper. For large theta-vacuum angle the chiral transition becomes ﬁrst order even if the quark number ch ... More
Presented by Takahiro SASAKI on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
Tri-hadron azimuthal correlations are studied in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV in ALICE. They are analyzed with one intermediate $p_T$ trigger to preferentially select on jets and two lower $p_T$ associated particles. With these correlations interaction of the jets and the medium can be studied. Three-particle correlations can give insight into the sources of modification to the jet ... More
Presented by Jason Glyndwr ULERY on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
The time evolution of the strongly interacting quark gluon plasma (sQGP) created in relativistic heavy ion collisions can be described by hydrodynamical models. Hadrons are created at the freeze-out of this fluid, thus their distributions reveal information about the final state. To access the time evolution and the initial state, one needs either additional information about the Equation of State ... More
Presented by Mate CSANAD on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Pre-equilibrium and initial state dynamics
The Quark-Gluon Plasma can be produced in high energy heavy ion collisions and how it equilibrates is important for the extraction of the properties of strongly interacting matter. A radiative transport model can be used to reveal interesting characteristics of Quark-Gluon Plasma thermalization. For example, screened parton interactions always lead to partial pressure isotropization. Systems with ... More
Presented by Bin ZHANG on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: New theoretical developments
We argue, using the AdS/CFT correspondence, that the transient dynamics of the shear stress tensor in a strongly coupled N = 4 SYM plasma is not described by relaxation-type, fluid dynamical equations: at long times the equations of motion should contain a second-order comoving derivative of the shear stress tensor. This occurs because in this strongly-coupled system the lowest “non-hydrody ... More
Presented by Jorge NORONHA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Using a microscopic transport model we investigate the evolution of conical structures originating from the supersonic projectile moving through the hot matter of ultrarelativistic particles. Using different scenarios for the interaction between projectile and matter, and different transport properties of the matter, we study the formation and structure of Mach cones. Especially, a dependence of t ... More
Presented by Ioannis BOURAS on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
In this work, we present how shear viscosity and entropy density behave in the Hadronic system as the number of Resonances produced are increasing. Shear viscosity is calculated by so called Chapman-Enskog approximation and cross-sections used in this calculation are taken from experiments and UrQMD model. One interesting results is we are able to approach the famous 1/4\pi limit for the ratio of ... More
Presented by Anton WIRANATA on 16 Aug 2012 at 16:00
We calculate P(k_perp), the probability distribution for an energetic parton propagating for a distance L through a medium to pick up transverse momentum k_perp, for a medium consisting of weakly coupled quark-gluon plasma. We use full or HTL self-energies in appropriate regimes, resumming each in order to find the leading large-L behavior. We estimate the jet quenching parameter and compare to r ... More
Presented by Mindaugas LEKAVECKAS on 16 Aug 2012 at 14:20
Type: Poster Session: Poster Session Reception
Track: Correlations and fluctuations
We report on the first study of transverse momentum differential correlation, $\la \Delta p_t \Delta p_t \ra$, in Pb - Pb collisions at \snn~= 2.76~TeV measured with the ALICE detector at the CERN Large Hadron Collider. We measure the two-particle correlation functions for $++$, $--$, and $+-$ charged particle pairs as a function of the pair azimuthal, $\Delta\phi$, and pseudorapidity, $\Delta\et ... More Presented by Claude Andre PRUNEAU on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Electroweak probes PHENIX has measured the e^{+}e^{-} pair continuum in sqrt(s_{NN})=200 GeV Au+Au and p+p collisions over a wide range of mass and transverse momenta. The e^{+}e^{-} yield is compared to the expectations from hadronic sources, based on PHENIX measurements. We investigate the effects of radial flow on the transverse mass dependence of the dilepton spectrum in min. bias Au+Au collisions in the low mas ... More Presented by Marton VARGYAS on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Global and collective dynamics Results of event-by-event simulations of a 3+1D viscous hydrodynamic model for Au-Au collisions at 200 GeV are presented. The fluctuations of the average transverse momentum in an event are determined by the fluctuations of the initial transverse size of the fireball. The mechanism involving transverse-momentum fluctuations from the initial size fluctuations, transmitted to the final statistica ... More Presented by Piotr BOZEK on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Global and collective dynamics Flow asymmetries are in focus of present heavy ion studies. In head-on collisions there would be no reason to have an azimuthal or longitudinal asymmetry, nevertheless, new observations for the higher harmonics show [1] that even in central collisions there is a strong azimuthal asymmetry in the emitted hadrons, and this asymmetry arises from transverse fluctuations of the initial state. This pose ... More Presented by Laszlo Pal CSERNAI on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Correlations and fluctuations Two particle correlations in azimuth and pseudorapidity encapsulate a wealth of information from jet correlations from medium response to bulk collective flow. The PHENIX Silicon Vertex Detector (VTX) is a cylindrical, 4-layer detector close to the beampipe which extends the PHENIX tracking capability to a pseudorapidity from -1 to +1 and over nearly the full azimuth. The first heavy ion data set ... More Presented by Theodore Koblesky THEO on 16 Aug 2012 at 16:00 Two particle correlations provide key information on the interactions between hard-scattered partons and the hot dense medium created by ultra-relativistic heavy ion collisions. An important aspect of extracting jet functions from correlation measurements in heavy ion collisions is to estimate the underlying event background level and its modulation by vn. This is essential for the goal of d ... More Presented by Takahito for the PHENIX Collaboration TODOROKI on 17 Aug 2012 at 15:00 Type: Poster Session: Poster Session Reception Track: Experiment upgrades, new facilities, and instrumentation The Compressed Baryonic Matter experiment at the future Facility for Antiproton and Ion Research will use a time-of-flight (TOF) wall for hadron identification, based on the MRPC technology. The challenge is to keep high efficiencies (above 90%) and good time resolutions (less than 80ps) at particle fluxes up to 20kHz/cm2, which is not accessible to conventional float-glass MRPCs. For this purpose ... More Presented by Mr. Jingbo WANG on 16 Aug 2012 at 16:00 Azimuthal anisotropic flows vn, arising from the anisotropic collision geometry, reflect the hydrodynamic properties of the quark gluon plasma created in relativistic heavy-ion collisions. A long standing issue in vn measurements is the contamination of nonflow, caused by intrinsic particle correlations unrelated to the collision geometry. Nonflow limits, in part, the precise extraction of the vis ... More Presented by Li YI on 15 Aug 2012 at 09:30 Type: Poster Session: Poster Session Reception Track: Correlations and fluctuations In heavy-ion collisions produced at the LHC a significant number of baryons is emitted in each collision. Two-particle correlations of those baryons carry important information about the emitting source and the interaction between them. At low relative momentum femtoscopic correlations arise, which are sensitive to the homogeneity lengths of the system. Hydrodynamic models predict that these w ... More Presented by Jai SALZWEDEL on 16 Aug 2012 at 16:00 Type: Poster Session: Poster Session Reception Track: Jets Correlations on transverse momentum$p_t$include important aspects of the six dimensional correlation space ($p_t1,\eta_1,\phi_1,p_t2,\eta_2,\phi_2$) [1]. Two-particle 2D correlations,$(p_t1,p_t2)$, for minimum-bias Au+Au collisions at$\sqrt{s_{NN}}=200$GeV from STAR show a broad peak extending from 0.5-4.0 GeV/c [2]. These correlations are formed from all charged particles with$p_t \geq 0. ... More
Presented by Elizabeth OLDAG on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 3B: Jets (Chair S. Mioduszewski)
Track: Jets
Hard probes are a cornerstone in the ongoing program to determine the properties of hot and dense QCD matter as created in ultrarelativistic heavy ion collisions. The first two runs at the LHC have resulted in a wealth of measurements of both reconstructed jets and single inclusive high P_T hadrons, opening new kinematic windows and offering high statistics. Yet on first glance, several observatio ... More
Presented by Thorsten RENK on 15 Aug 2012 at 08:30
Type: Oral Presentation Session: Teacher's Day
Presented by Paul CHESLER on 12 Aug 2012 at 14:35
Type: Poster Session: Poster Session Reception
Track: Jets
Observables involving fully reconstructed jets provide access to key properties of the quark-gluon plasma via partonic energy loss. In order to obtain the inclusive transverse momentum distribution of fully reconstructed jets using the ALICE tracking detectors and electromagnetic calorimeter, the smearing effect of non-ideal detector responses must be understood and corrected. The procedure for as ... More
Presented by Andrew Marshall ADARE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
Studies of proton (deuteron) - nucleus collisions allow for the detailed examination of cold nuclear matter effects (including gluon saturation, initial state parton energy loss, nuclear break up and others), while also providing a crucial baseline for nucleus-nucleus collisions with additional hot quark-gluon plasma effects. The PHENIX experiment is planning an ambitious upgrade program re ... More
Presented by Prof. Seto RICHARD on 16 Aug 2012 at 16:00
At the LHC the ALICE experiment is taking data in p+p, p+A and A+A collisions, which is providing unique insights on strongly interacting matter at an unprecedented energy density. Many important questions in heavy-ion physics will, however, remain unanswered in this first running period up to 2017. Only by increasing the luminosity beyond 10^27 and exploiting recent advances in technology ALICE w ... More
Presented by Thomas PEITZMANN on 17 Aug 2012 at 14:40
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
We suggest that the combined effect of screening, gluon-induced dissociation, Landau damping, and reduced feed-down explains most of the suppression of Y states that has been observed by CMS [1] in PbPb relative to pp collisions at sqrt(s_NN) = 2.76 TeV at the CERN LHC. The suppression is thus a clear, albeit indirect, indication for the presence of a qgp. In particular, we calculate the suppre ... More
Presented by Georg WOLSCHIN on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
We study the interesting similarities between the physics of cosmic microwave background radiation anisotropies and the flow anisotropies in relativistic heavy ion collision experiments. Further we explore how the techniques in CMBR analysis could be utilized in studying the flow anisotropies in RHICE. We argue that the initial state fluctuations of the matter formed in heavy ion collisio ... More
Presented by Ms. P S SAUMIA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Electroweak probes
The HADES experiment, installed at the Helmholtzzentrum für Schwerionenforschung (GSI) accelerator facility in Darmstadt, investigates dielectron emission and strangeness production in various collision systems (p+p, p+n, p+A and A+A) in the 1-3.5 AGeV regime. The observed low-mass dielectron and Ξ- enhancement in intermediate heavy-ion collisions indicates the onset of medium effects, on the ... More
Presented by Mr. Manuel LORENZ on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
Comparing hydrodynamic simulations to data inevitably requires the conversion of the fluid to particles. This conversion is ambiguous for viscous fluids as an infinite class of phase space densities can produce the same hydrodynamic variables. We compute self-consistent phase space corrections for hadron species by solving the linearized Boltzmann equation. These distribution functions are then ... More
Presented by Mr. Zachary WOLFF on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Teacher's Day
Presented by Hannah PETERSEN on 12 Aug 2012 at 13:00
on 13 Aug 2012 at 08:30
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
\bc {\large \bf{ Why the formula\\ $\mean{dN_{\rm ch}^{AA}/d\eta}=\mean{dN_{\rm ch}^{pp}/d\eta} [x N_{\rm part}/2 +(1-x) N_{\rm coll}]$\\ should be deprecated}} \bs Abstract for Quark Matter 2012 poster \bs \underline{Michael J. Tannenbaum}~$^{a)}$ $^{a)}$ Physics Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA The fact that the multiplicity density in A+A colli ... More
Presented by Michael TANNENBAUM on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
We calculate the expectation of Xi yields in nuclear collisions at SIS energies for the case that the produces strangeness is distributed statistically over S<0 species. By taking into account that cascades are produced only in events where two kaons are produced we obtain theoretical value which is about 1/2 of that reported in previous calculations. Even possible modifications of hadron properti ... More
Presented by Boris TOMASIK on 16 Aug 2012 at 16:00
Type: Oral Presentation Session: Parallel 4C: Electro-Weak Probes (Chair D. D'Enterria)
Track: Electroweak probes
The Compact Muon Solenoid (CMS) is fully equipped to measure leptonic decays of electroweak probes in the high multiplicity environment of nucleus-nucleus collisions. Electroweak boson production is an important benchmark process at hadron colliders. Precise measurements of W and Z production in heavy-ion collisions can help to constrain nuclear PDFs as well as serve as a standard candle of the in ... More
Presented by Lamia BENHABIB on 15 Aug 2012 at 12:00
Type: Poster Session: Poster Session Reception
Track: Heavy flavor and quarkonium production
Measurement of different quarkonia states is a well known tool for study of hot and dense matter produced in heavy ion collisions. The PHENIX experiment at RHIC have successfully measured chi_c production in p+p and d+Au collisions at 200 GeV. The chi_c decays were reconstructed through their decays to J/Psi+gamma. Results from the 2006 p+p and 2008 d+Au datasets at 200GeV will be present ... More
Presented by Dr. Alexandre LEBEDEV on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
We will address the possibility of QGP formation in pp at 7TeV and 14 Tev with given life scan and size of QGP based on quantitative model estimation and constrained with all available data at LHC from the four collaborations. Then discuss the possible QGP signals in pp collisions, which certainly differ to the QGP signals in AA collisions. To theoreticians: Most of you think QGP formation ... More
Presented by Fuming LIU on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Exploring the QCD phase diagram
The study of phi meson and multi-strange production in heavy ion collision are the most interesting observables for exploring the new phase of matter named Quark Gluon Plasma. We will investigate the phi-meson and multi-strange production at FAIR energies using transport models like Ultra Relativistic Quantum Molecular Dynamics (UrQMD)[1] and A Multi Phase Transport Model (AMPT)[2]. The UrQMD mode ... More
Presented by Mr. Mukesh MUKESH KUMAR SHARMA on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Experiment upgrades, new facilities, and instrumentation
Reconstructed jets in heavy ion collisions are a crucial tool for understanding the quark-gluon plasma. The separation of jets from the underlying event is necessary, particularly in central heavy ion collisions, in order to quantify medium modifications of the parton shower. Here, we describe a method for quantifying the underlying event contributions in Au+Au collisions at \$\sqrt{s_{NN}} ... More
Presented by Anne SICKLES on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Jets
The PHENIX Experiment is proposing an exciting suite of upgrades called sPHENIX, with a first stage including a world class jet detector with full electromagnetic and hadronic calorimetry capable of sampling up to 50 billion Au+Au collisions annually and measuring jets over a broad kinematic range and with high statistics (over 10 million jets above 20 GeV and over 100,000 jets above 40 GeV). Th ... More
Presented by Prof. Jamie NAGLE on 16 Aug 2012 at 16:00
Type: Poster Session: Poster Session Reception
Track: Global and collective dynamics
vSPheRIO is a new second order viscous hydrodynamic code for ultrarelativistic heavy ion collisions that can be consistently run on an event-by-event basis. This code, which is the viscous generalization of the well known SPheRIO code \cite{Aguiar:2000hw}, solves second order viscous hydrodynamic equations. In this talk, we use vSPheRIO to investigate the time evolution of a boost invariant QGP, ... More
Presented by Jacquelyn NORONHA-HOSTLER on 16 Aug 2012 at 16:00