Description
Posters will be displayed in the Ambassador Room and part of the Regency Room. They will be available for viewing from Tuesday to Thursday.
Prof.
Vincenzo Greco
(University of Catania)
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
Riccardo Russo
(Universita e INFN (IT))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Dirk Rischke
(U)
16/08/2012, 16:00
Electroweak probes
Poster
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...
J. Matthew Durham
(Los Alamos National Laboratory)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Prof.
Yuanfang Wu
(Institute of Particle Physics, CCNU, Wuhan China)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Taku Gunji
(University of Tokyo (JP))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
499.
A novel high momentum particle identification detector for the next generation ALICE experiment
Austin Vincent Harton
(Chicago State University (US))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Dr
Yuji Sakai
(RIKEN)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
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}...
Eric Mannel
(B)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Kurt Jung
(Purdue University (US))
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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...
Michael McCumber
(University of Colorado)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Dr
Thomas Kiess
(self)
16/08/2012, 16:00
New theoretical developments
Poster
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”...
Nikola for the ALICE-FoCal collaboration Poljak
(NIKHEF/Univeristy of Utrecht)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Xiangrong Zhu
(Central China Normal University CCNU (CN))
16/08/2012, 16:00
Jets
Poster
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...
Dr
Frederique Grassi
(Universidade de Sao Paulo, Brazil)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
You Zhou
(Nikhef and Utrecht University (NL))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Mr
Yuji Hirono
(The University of Tokyo)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
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...
Joshua Ilany
(Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Shikshit Gupta
(University of Jammu)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Mr
Christopher Yaldo
(Wayne State University)
16/08/2012, 16:00
Jets
Poster
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...
Heikki Mäntysaari
(University of Jyväskylä, Department of Physics)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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...
Deepa Thomas
(University of Utrecht (NL))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Wei Li
(MIT)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Mohammed Younus
(Variable Energy Cyclotron Centre)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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.
Bogdan Theodor Rascanu
(Johann-Wolfgang-Goethe Univ.)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Alis Rodriguez Manso
(NIKHEF (NL))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Dr
Kenji Morita
(Kyoto University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Enrico Fragiacomo
(Universita e INFN (IT))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
Hui Wang
(Michigan state university)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Michal Petran
(Czech Technical University (CZ))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
John Campbell
(T)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Andrej Ficnar
(Columbia University in the City of New York)
16/08/2012, 16:00
New theoretical developments
Poster
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...
jie zhao
(lbl&sinap)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Xiangli Cui
(U)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
387.
Charge Asymmetry Dependency of $\pi^+/\pi^-$ Azimuthal Anisotropy in Au + Au Collisions at STAR
Hongwei Ke
(Central China Normal University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Guo-Liang Ma
(Shanghai INstitute of Applied Physics (SINAP), CAS)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Charles Riley
(Yale University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Jocelyn Mlynarz
(Wayne State University (US))
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Michal Petran
(Czech Technical University (CZ))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
Peter Levai
(Hungarian Academy of Sciences (HU))
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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...
Dr
Alexandre Lebedev
(Iowa State University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Mr
Vasily Sazonov
(University of Graz)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
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...
Christian Wesp
(Goethe Universität Frankfurt)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Edward Shuryak
(stony brook university)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Dr
brijesh srivastava
(Purdue University)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Kwangbok Lee
(Losalamos National Laboratory)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
$\Upsilon(1S+2S+3S)$ 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...
Dr
Armen Sedrakian
(Frankfurt University)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
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...
Prof.
Alexandru Jipa
(Faculty of Physics, University of Bucharest)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Damian Reynolds
(S)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Stephen Horvat
(Y)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Dr
Irakli Garishvili
(Lawrence Livermore National Laboratory)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Dr
Thomas Hell
(Technische Universität München)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Yi Wang
(Department of Engineering Physics, Tsinghua University)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Prof.
Yuanfang Wu
(Institute of Particle Physics, CCNU, wuhan China)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Prof.
Yuanfang Wu
(Institute of Particle Physics, CCNU, Wuhan, China)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Fiorella Fionda
(Universita e INFN (IT))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Grazia Luparello
(NIKHEF (NL))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Sandro Bjelogrlic
(University of Utrecht (NL))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Chanaka De Silva
(Wayne State University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Christoph Herold
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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.
Dr
Juergen Eschke
(GSI Helmholtzzentrum)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Taku for the ALICE-FOCAL Collaboration Gunji
(University of Tokyo (JP))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Deepali Sharma
(S)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Tatsuya Chujo
(University of Tsukuba (JP))
16/08/2012, 16:00
Jets
Poster
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...
Mr
Patrick Huck
(CCNU/LBNL)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Mr
Florian Senzel
(Goethe-Universität Frankfurt)
16/08/2012, 16:00
Jets
Poster
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...
Antonio Uras
(Universite Claude Bernard-Lyon I (FR))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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 ($2.5 < \eta < 4$)...
Nowo Riveli
(O)
16/08/2012, 16:00
Jets
Poster
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...
Bikash Sinha
(V)
16/08/2012, 16:00
New theoretical developments
Poster
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...
Sarah Campbell
(I)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Baldo Sahlmueller
16/08/2012, 16:00
Jets
Poster
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...
Ekaterina Retinskaya
(IPhT Saclay)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Gyulnara Eyyubova
(University of Oslo (NO))
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Akihiko Monnai
(The University of Tokyo)
16/08/2012, 16:00
Global and collective dynamics
Poster
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....
Pasi Huovinen
(Johann Wolfgang Goethe-Universität)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Mr
Zhiming Li
(Institute of Particle Physics, CCNU, Wuhan, China)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Mate Csanad
(for the TOTEM Collaboration)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Hamza Berrehrah
(Subatech)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Monika Sharma
(Vanderbilt University (US))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Denise Aparecida Moreira De Godoy
(Universidade de Sao Paulo (BR))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Carlos Perez Lara
(Nikhef, Utrecht University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Maja Katarzyna Mackowiak-Pawlowska
(Johann-Wolfgang-Goethe Univ. (DE))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Dr
Anar Rustamov
(Frankfurt University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Prof.
Ricardo Rodriguez
(Ave Maria University)
16/08/2012, 16:00
Jets
Poster
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...
Hideaki Iida
(Kyoto University)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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)...
Dr
Takashi Hachiya
(RIKEN)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Anthony Robert Timmins
(University of Houston (US))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Dr
Harri Niemi
(University of Jyväskylä, Department of Physics)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Koichi Murase
(The University of Tokyo)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Xu-Guang Huang
(Institute for Theoretical Physics)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Stefan Thomas Heckel
(Johann-Wolfgang-Goethe Univ. (DE))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Christoph Mayer
(Polish Academy of Sciences (PL))
16/08/2012, 16:00
Electroweak probes
Poster
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...
Kouji Kashiwa
(RIKEN BNL Research Center)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Philipe Mota
(Goethe Universität Frankfurt)
16/08/2012, 16:00
Global and collective dynamics
Poster
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....
354.
Fluctuating Hydrodynamics Confronts the Rapidity Dependence of Transverse Momentum Fluctuations
Sean Gavin
(Wayne State University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Taku Gunji
(University of Tokyo (JP))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Dr
Sascha Vogel
(Frankfurt Institute for Advanced Studies)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Dr
Aneta Iordanova
(University of California, Riverside)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Elena Petreska
(Graduate Center/Baruch College CUNY)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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...
Paul Hohler
(Texas A&M University)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
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...
Oliver Fochler
(Goethe-Universität Frankfurt)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Prof.
Masayuki Asakawa
(Osaka University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Daisuke Watanabe
(University of Tsukuba (JP))
16/08/2012, 16:00
Jets
Poster
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...
Dr
Edouard Kistenev
(Brookhaven National Laboratory)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Dmitri Kotchetkov
(Ohio University (US))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Sungtae Cho
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
Mr
Philip Rau
(Goethe University Frankfurt, Germany)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Francesco Becattini
(Unversity of Florence), Mr
Tim Schuster
(Yale University (US))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
George Moschelli
(Frankfurt Institute for Advanced Studies)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Alex Mwai
(Stony Brook University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Gunnar Gräf
(Frankfurt Institute for Advanced Studies)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Dr
Daniel Kikola
(Purdue University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Dr
Sascha Vogel
(Frankfurt Institute for Advances Studies)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Sanghoon Lim
(Yonsei University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Mr
Nirupam Dutta
(Doctoral Student, Bielefeld University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Dr
Hendrik van Hees
(Goethe University Frankfurt)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Prof.
Feng Liu
() College of Physical Science and Technology, Central China Normal University, Wuhan, 430079, China)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Jan Cepila
(Czech Technical University (CZ))
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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...
Norbert Novitzky
(Helsinki Institute of Physics (FI))
16/08/2012, 16:00
Jets
Poster
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...
amal sarkar
(Indian Institute of Technology, Mumbai)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
NIHAR R SAHOO
(Variable Energy Cyclotron Centre)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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....
Philipp Gubler
(RIKEN)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Rone Andrade
(Universidade de São Paulo USP)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Guang-You Qin
(Duke University/Wayne State University)
16/08/2012, 16:00
Jets
Poster
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...
Dr
Jan Steinheimer-Froschauer
(Lawrence Berkeley National Laboratory)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Matthew Donald Steinpreis
(Ohio State University (US))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Jonathan Bouchet
(Kent State University),
Joseph Vanfossen
(Kent State University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Prof.
Ramona Vogt
(LLNL and UC Davis)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
John Novak
(M)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Dr
Marlene Nahrgang
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Liliana Apolinário
(Universidade de Santiago de Compostela)
16/08/2012, 16:00
Jets
Poster
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...
Dr
Sascha Vogel
(Frankfurt Institute for Advanced Studies)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Prof.
Toshitaka Tatsumi
(Department of Physics, Kyoto University)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Ioannis Bouras
(University of Frankfurt a.M.)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Dr
Cesar L. for the PHENIX Collaboration Silva
(Los Alamos National Lab)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Kenta Shigaki
(Hiroshima University (JP))
16/08/2012, 16:00
Electroweak probes
Poster
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....
Mr
L. Chanaka De Silva
(University of Houston)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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}...
Prof.
Tomoki Endo
(Division of Physics, Department of General Education, Kagawa National College of Technology, Japan.)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Mauro Rogerio Cosentino
(Lawrence Berkeley National Lab. (US))
16/08/2012, 16:00
Electroweak probes
Poster
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...
Wangmei Zha
(U)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Marcel Araujo Silva Figueredo
(Universidade de Sao Paulo (BR))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Thomas Lang
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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.
Michal Vajzer
(Acad. of Sciences of the Czech Rep. (CZ))
16/08/2012, 16:00
Jets
Poster
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...
Dr
J. Ali Hanks
(PHENIX)
16/08/2012, 16:00
Jets
Poster
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...
Ying Lu
(University of Maryland (US))
16/08/2012, 16:00
Jets
Poster
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...
Di-Lun Yang
(D)
16/08/2012, 16:00
Jets
Poster
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...
Dosatsu Sakata
(University of Tsukuba (JP))
16/08/2012, 16:00
Jets
Poster
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...
Pengfei Zhuang
(Tsinghua University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Hua Pei
(University of Illinois at Chicago)
16/08/2012, 16:00
Jets
Poster
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...
Akira Ohnishi
(Kyoto University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
W.J. Llope
(Rice University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Sudipan De
(Department of Atomic Energy (IN))
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Dr
Huang Bingchu
(Brookhaven National Lab)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Frasher Loshaj
(S)
16/08/2012, 16:00
Jets
Poster
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...
Emilia Leogrande
(Universita e INFN (IT))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Edward Shuryak
(stony brook university)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Ryohji (for the PHENIX collaboration) Akimoto
(University of Tokyo)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Heavy quarks (charms and bottoms) are interesting probes with which to study the properties of quark gluon plasma (QGP). Heavy quarks are created by initial hard scatterings, and thus are good probe to investigate the full time evolution of heavy ion collisions. Due to their heavy mass, the energy loss within the QGP is expected to be different for heavy quarks than for light quarks....
Shawn Whitaker
(Iowa State University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
The suppression of quarkonia in heavy ion collisions has long been thought to provide an indication of the temperature dependent Debye screening length of color charge in the quark gluon plasma. A large sample of Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV have been collected by PHENIX in 2010. Using the PHENIX measurement of Upsilon production in p+p collisions as a reference, we will present...
Zubayer Ahammed
(Department of Atomic Energy (IN))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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Christoph Baumann
(Johann-Wolfgang-Goethe Univ. (DE)),
Markus Kohler
(GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))
16/08/2012, 16:00
Electroweak probes
Poster
Direct photons are an important probe of the hot and dense medium created in heavy-ion collisions because they do not interact with the medium and therefore carry information of all stages of the collision.
At low momenta, thermal emission, which would provide the ideal measurement of temperature of the quark-gluon plasma, is expected to dominate over other sources of direct photons. However,...
Satyajit Jena
(IIT- Indian Institute of Technology (IN))
16/08/2012, 16:00
Correlations and fluctuations
Poster
Charge fluctuations are considered to provide a possible signature for the existence of the de-confined Quark Gluon Plasma phase (QGP). Charge fluctuations are sensitive to the number of charges in the system, thus the fluctuations in the QGP, with fractionally charged partons, are significantly different from those of hadron gas with unit charged particles. The study of charge fluctuations...
Satoshi Yano
(Hiroshima University (JP))
16/08/2012, 16:00
Jets
Poster
The $\omega$ meson is a promising probe to investigate the properties of the QGP. It is well known that the yield of high-p_t particles is suppressed in nucleus-nucleus collisions relative to that in pp collisions.
The effect is attributed to the energy loss of the energetic parent partons traversing the created medium.
Since $\pi^0$ and $\omega$ mesons have the same quark content (u and d),...
Tomasz Bold
(AGH Univ. of Science amp; Technology, Krakow)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
The results of the study of ultraperipheral (gamma-gamma and gamma-Pomeron) interactions are presented. The analysis was performed with the data recorded by the ATLAS experiment during LHC Pb-Pb run in year 2011. The data, taken at the beam energy of 2.75 TeV per nucleon, correspond to an integrated luminosity of 141/microbarn. Muon pairs, produced in pure electromagnetic two-photon...
Bernard Richard Hicks
(Yale University (US))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Heavy quarks, being produced in the initial stages of heavy-ion collisions, provide an excellent probe for the properties of the quark-gluon plasma (QGP). The expected in-medium energy loss of quarks is predicted to have a mass-dependence; however, recent results indicate that heavy-quarks lose more energy than expected. The measurement of electrons from heavy flavor decays provides insight...
326.
Measurements of anisotropic flow($v_n$, n=1,2,3,4) in Cu + Au collisions at 200 GeV from PHENIX
Dr
shengli huang
(PHENIX Collaboration)
16/08/2012, 16:00
Global and collective dynamics
Poster
Measurements of the anisotropic flow with different order harmonic
coefficients ($v_n$, n=1,2,3,4) have played a pivotal role in the
discovery of the strongly coupled quark-gluon plasma (sQGP) at
RHIC. They are also important for the study of the viscous
hydrodynamics and the extraction of the shear viscosity over
entropy density ($\eta/s$). The anisotropic flow is strongly
coupled with...
Sidharth Kumar Prasad
(Wayne State University (US))
16/08/2012, 16:00
Jets
Poster
We present results of a study of charged particle jet properties in pp
collisions at $\sqrt{s}$ = 7 TeV using the ALICE detector.
Jets are reconstructed using charged tracks at mid-rapidity with the
anti-$\rm k_{t}$ [1] jet finding algorithm from FastJet.
We will discuss the transverse momentum dependence of three jet
properties: charged particle multiplicity, jet size, and...
Rongrong Ma
(Yale University (US))
16/08/2012, 16:00
Jets
Poster
Jet properties are expected to be modified in the dense, colored medium formed in Pb-Pb collisions at the LHC. To quantify such modifications, the measurement of reference distributions in pp collisions is essential. Jets are reconstructed from charged tracks measured in the ALICE central barrel, as well as the neutral energy measured in the Electromagnetic Calorimeter (EMCal). In this poster,...
Szymon Mateusz Pulawski
(University of Silesia (PL))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
Preliminary NA61/SHINE results on π+, π-, K+, K-, p and pbar spectra in p+p interactions at 20-158 GeV/c will be presented. NA61/SHINE at the CERN SPS is a fixed-target experiment pursuing a rich physics program [1]. Thanks to its large acceptance and excellent particle identification capability NA61/SHINE is well suited for performing high-precision particle production measurements in p+p,...
Benjamin Bannier
16/08/2012, 16:00
Electroweak probes
Poster
Photons are produced at all stages of a nuclear collision. Because of their
extremely small interaction rate with the hadronic medium any information they
carry about their production environment is accessible nearly undistorted in
their final state. Photons are produced in hadronic decays, hard scatterings
of initial state partrons, jet-photon conversions and from thermal radiation
of...
Karoly Uermoessy
(Hungarian Academy of Sciences (HU))
16/08/2012, 16:00
New theoretical developments
Poster
For the description of hadronic spectra in high-energy nuclear reactions, it is essential to understand the process of hadronisation. However, hadron creation is still an unsettled matter from the theoretical point of view.
In the talk, I show that hadron distributions inside jets (fragmentation functions) created in s^1/2 = 7 TeV (LHC) proton-proton [1] and also in high-energy...
Dr
Daniel Kikola
(Purdue University)
16/08/2012, 16:00
Global and collective dynamics
Poster
Anisotropic flow, which arises from correlations to the common collision geometry, is sensitive to the early stage of the expansion of the medium created in relativistic heavy-ion collisions. Azimuthal anisotropy is measured by final state particle correlations and is thus contaminated by correlations unrelated to the common geometry (nonflow). The contamination of nonflow hampers further...
Dr
Paul Stankus
(Oak Ridge National Lab)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
The large majority of observations made of high-energy heavy-ion collisions at RHIC and LHC have been within a narrow range at mid-rapidity. These have been greatly informative, of course; but they've provided a window only onto a central "slice" of the created medium, leaving the full 3-D picture of the collision as a relatively unexplored frontier. How the initially locally thermalized...
Jussi Auvinen
(University of Jyväskylä)
16/08/2012, 16:00
Jets
Poster
A strong suppression of heavy-flavor hadrons has been seen in ultrarelativistic heavy ion collisions at BNL-RHIC and CERN-LHC. This surprising result has challenged the view of gluon radiation dominating over elastic 2-to-2 processes as a cause of parton energy loss in a quark-gluon plasma. To study the effectiveness of elastic collisions as the suppression mechanism in detail, we have...
Clint Young
(McGill University)
16/08/2012, 16:00
Jets
Poster
Jets have proven to be an important observable of heavy-ion collisions at the LHC; recent analysis has also made jets an important probe at RHIC energies as well. Unlike the spectrum of single hadrons, the spectrum of jets is highly sensitive to $\hat{q}_{\perp}$, as well as being sensitive to partonic energy loss and radiative processes. We use MARTINI, an event generator, to study how...
Prof.
Jens Jorgen Gaardhoje
(Niels Bohr Institute)
16/08/2012, 16:00
Global and collective dynamics
Poster
We discuss opportunities that may arise from subjecting high-multiplicity events in relativistic heavy ion collisions to an analysis similar to the one used in cosmology for the study of fluctuations of the Cosmic Microwave Background (CMB). To this end, we discuss examples of how pertinent features of heavy ion collisions including global characteristics, signatures of collective flow and...
Ms
Dronika Solanki
(University of rajasthan)
16/08/2012, 16:00
Global and collective dynamics
Poster
The main goal of the STAR experiment at Relativistic Heavy Ion Collider (RHIC) is to study the properties of the QCD matter at extremely high energy density and parton density, created in the heavy ion collisions. Photons are produced at all stages of the colliding system and through decay of produced particles like neutral pions. The multiplicity measurement of photons on an event-by-event...
Fengchu Zhou
(Central China Normal University (CN))
16/08/2012, 16:00
Global and collective dynamics
Poster
A central goal of the heavy-ion program at LHC is to study the properties of the quark-gluon plasma (QGP). The azimuthal anisotropy of particle production is a sensitive tool to study the features of the QGP. The anisotropy is typically characterized by $v_2$, the second harmonic coefficient of the Fourier series expansion of the particle azimuthal distribution with respect to the reaction...
Paraskevi Ganoti
(Oak Ridge National Laboratory - (US))
16/08/2012, 16:00
Jets
Poster
In this poster, $\pi^0$ and $\eta$ spectra in pp collisions at sqrt(s) = 7 TeV from the ALICE 2010 and 2011 runs (extended calorimeter acceptance) will be presented.
The neutral mesons are reconstructed via their two photon decay channel where both photons are measured with the ALICE EMCal. For the ALICE 2011 run both, minimum bias and EMCal triggered data, have been analyzed. A precise...
Mr
Matthias Drews
(Technische Universitaet Muenchen)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
Recently a two-solar-mass neutron star was observed. This puts new constraints on effective models at zero temperature and high chemical potential. In our approach we include mesonic degrees of freedom as well as nucleons in the framework of the Functional Renormalization Group. In this way, fluctuations beyond the mean-field approximation are taken into account.
Gyulnara Eyyubova
(University of Oslo (NO))
16/08/2012, 16:00
Global and collective dynamics
Poster
Recently significant effort is made to study azimuthal flow asymmetries in ultra-relativistic heavy ion reactions. At finite impact parameters the directed flow and the elliptic flow were dominant observables for many years.
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...
Amaresh Jaiswal
(Tata Institute of Fundamental research, Mumbai)
16/08/2012, 16:00
New theoretical developments
Poster
Starting with the relativistic Boltzmann equation where the collision term is generalized to include nonlocal effects, and using Grad's 14-moment approximation for the single-particle distribution function, we derive equations for the relativistic dissipative fluid dynamics. We compare them with the corresponding equations obtained in the standard Israel-Stewart and related approaches. Our...
Mr
Risto Paatelainen
(University of Jyvaskyla, Finland)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
The EKRT model [1] which combines pQCD minijet production with the saturation of produced gluons and (ideal) hydrodynamics, has predicted the measured multiplicities in central A + A collisions both at RHIC and LHC remarkably well [2]. Also the published pT spectra of bulk hadrons (at RHIC) have been reproduced quite nicely [3]. We now bring this closed framework to NLO as rigorously as...
Erike Cazaroto
(University of Sao Paulo)
16/08/2012, 16:00
Global and collective dynamics
Poster
At high energies the amount of gluons in a hadron is much larger than the amount of any other constituent, for example it is much larger than the amount of sea quarks. Therefore, at high energies the hadronic cross sections are basically a function only of the gluons distribution. The color dipole formalism applied to photon-photon collisions implies that, before interacting, each of the...
Dr
Min He
(Cyclotron Institute, Texas A&M University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
We compute open heavy-flavor (HF) transport in relativistic heavy-ion collisions by combining a strong-coupling treatment in both macro- and microscopic dynamics (hydro and nonperturbative diffusion interactions) [1]. The hydrodynamic bulk evolution is quantitatively constrained by bulk and multi-strange hadron spectra and elliptic flow [2]. In the Quark-Gluon Plasma (QGP) phase, heavy-quark...
Mauricio Martinez Guerrero
(Universidade de Santiago de Compostela)
16/08/2012, 16:00
New theoretical developments
Poster
Radiative interferences in the multiparton shower is the building block of QCD jet physics in vacuum. The presence of a QCD medium is expected to alter this interference pattern. We investigate color coherence effects in the medium modification to the initial state radiation in a simple setup which allows to include these effects in a clean way. We derive the medium induced gluon spectrum of...
Alexander Schmah
(Lawrence Berkeley National Lab)
16/08/2012, 16:00
Global and collective dynamics
Poster
The RHIC Beam Energy Scan covers a wide range in the QCD phase diagram temperature vs. baryon chemical potential. A phase transition between the Quark Gluon Plasma and the hadron gas phase is expected in this region of the QCD phase diagram. The elliptic flow $v_{2}$ is one of the observables which is sensitive to the pressure gradients in the initial stage of heavy-ion collisions. Hence it...
Joshua Konzer
16/08/2012, 16:00
Jets
Poster
Particle production mechanisms vary with $p_T$. At low $p_T$ soft processes dominate whereas hard processes dominate at higher $p_T$. Experimental data has shown drastic change from d+Au to Au+Au collision in $p_T$ spectra, collective phenomena, and baryon/meson ratio at intermediate $p_T$. This indicates that the relative mixture of particles produced by hard and soft processes differ...
Anthony Robert Timmins
(University of Houston (US))
16/08/2012, 16:00
Correlations and fluctuations
Poster
The large multiplicities at the LHC potentially permit azimuthal flow to be accurately determined on an event by event basis in heavy-ion collisions. I will discuss methods one can obtain full vn distributions from such measurements. In particular, any measurement of event-wise flow will be subject to statistical smearing, and I will review unfolding techniques to recover the true vn...
Fuming Liu
(Central China Normal University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Tamal Kumar Mukherjee
(Institute of High Energy Physics, TPCSF)
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
We follow chiral effective model [1] of a quarkonia nonet and a tetraquark nonet as well as a complex iso-singlet (glueball) field to study the lowest lying scalar mesons on the basis of chiral symmetry and UA(1) symmetry. By virtue of the isospin symmetry, the isospin 1 and isospin 1/2 physical states are assumed to have two and four bare quark components whereas I = 0 physical scalar and...
Jan Uphoff
(Goethe University Frankfurt)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
The production and space-time evolution of heavy quarks and J/psi in the quark gluon plasma is studied within the partonic transport model Boltzmann Approach to MultiParton Scatterings (BAMPS). An updated version of BAMPS is presented which allows interactions among all partons: gluons, light quarks and heavy quarks. Heavy quarks, in particular, interact with the rest of the medium via binary...
Mr
Hongxi Xing
(Institute of Particle Physics, Central China Normal University)
16/08/2012, 16:00
Jets
Poster
Within the framework of generalized collinear factorization in perturbative QCD (pQCD), we study the effect of initial multiple parton scattering and induced parton energy loss in Drell–Yan (DY) process in proton–nucleus collisions. We express the contribution from multiple parton scattering and induced radiative energy loss to the DY dilepton spectra in terms of nuclear modified effective...
Hidemitsu Asano
(Kyoto Univ.)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) at
Brookhaven National Laboratory has been upgraded by installing a
Silicon Vertex Tracker (VTX). The VTX has been developed for heavy flavor (charm and bottom) measurements and dedicated to precise tracking of primary and secondary vertices. Resolution of primary vertex reconstruction and distance of closet approach (DCA)...
Chi Yang
(U)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
A larger area of muon telescope detector(MTD) at mid-rapidity will provide excellent muon identification and trigger capabilities at mid-rapidity in the high-luminosity era at RHIC. This novel and compact detector can provide crucial measurements for many exciting physics perspectives. We can measure different Upsilon states and J/psi over a broad transverse momentum range through di-muon...
Libor Skoda
(Czech Technical University (CZ))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
We present a performance study of a compact electromagnetic calorimeter meant to serve in a forward region (2 < eta < 4.5) in collider experiments in pp, pA and AA collisions. This kinematic region at LHC energies allows one to study very low Bjorken x physics. Measurement of direct photons in this region enables one to improve the precision of (nuclear) parton distribution functions.
Our...
Pilar Staig
(Stony Brook University)
16/08/2012, 16:00
Global and collective dynamics
Poster
We study the effect that perturbations and their propagation through the medium have in the final particle distributions of heavy ion collisions. Our work is constrained to central collisions only, where the medium can be described by the solution to conformally invariant hydrodynamics developed by Gubser and Yarom, which is a generalization of Bjorken flow where the boost-invariant medium...
Kyohei Fukuda
(Nagoya)
16/08/2012, 16:00
Global and collective dynamics
Poster
We discuss the evolution of the fluctuation in the initial conditions
of entropy densities (energy densities) using 1+1 dimensional hydrodynamic calculations.
We explore not only the evolution of the fluctuation but also the origin of it.
If the local thermal equilibrium is established at early time of the heavy ion collision
and the mean free path of produced particles is...
Mr
Abhisek Sen
(Georgia State University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
$J/\psi$ production is considered as one of the very important probes for studying the properties of quark-gluon plasma (QGP). PHENIX observed a large suppression of $J/\psi$ production in Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeV in comparison with binary collision scaled p+p collisions. The level of this suppression is similar to that observed in other energies in CERN-SPS and LHC. ...
Lei Ding
(I)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
The measurement of azimuthal anisotropy $v_{2}$ of single electrons from semi$-$leptonic decay of open heavy flavor mesons in PHENIX experiment has provided important understanding of the property of the quark gluon plasma, especially the geometrical dependence of partonic energy loss. PHENIX results of $v_{2}$ in Au$+$Au collision at $\sqrt{s_{NN}}$=200GeV for heavy-flavor decays are...
Antonio Uras
(Universite Claude Bernard-Lyon I (FR))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
Strangeness production provides one of the key observables to characterize the hot and dense state of strongly interacting matter produced in high-energy nuclear collisions. To access this information, ALICE measured phi meson production both in proton-proton and Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV in the dimuon channel, in the rapidity region 2.5 < y < 4. Thanks to these measurements,...
Mr
Mukesh Mukesh Kumar Sharma
(University Of Jammu)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Mr
Guangyao Chen
(Cyclotron Insitute and Department of Physics&Astronomy, Texas A&M University)
16/08/2012, 16:00
Electroweak probes
Poster
A new source of photon and dilepton emission from nuclear matter undergoing phase transition from partonic to hadronic degrees of freedom is studied. Electromagnetic radiation can be emitted when quark antiquark pairs recombine into pions and other hadrons. The photon and dilepton production rates are found to be comparable to those in quark gluon plasma and hadronic matter around the critical...
Dr
Martin Purschke
(BROOKHAVEN NATIONAL LABORATORY, for the PHENIX Collaboration)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
The initial stage of the sPHENIX upgrade detector at RHIC will focus on the measurement of jet observables, such as gamma-jet properties, withhigh statistics over a large kinematic range. We have studied several key performance parameters of the envisioned electromagnetic calorimeter. In this poster we will present the studies of the photon identification in the presence of the particle...
Pat Kenny
(University of Kansas (US))
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
Ultra-peripheral collisions (UPCs) of heavy ions involve long range electromagnetic interactions at impact parameters larger than twice the nuclear radius. At TeV energies, the strong electromagnetic field due to the coherent action of the Z=82 proton charges generates a large flux of photons, which can be used for high-energy photoproduction studies. Heavy vector mesons (for example J/psi,...
Mr
Yan Yang
(Ohio State University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
Correlations between non-identical particles at low relative momentum
in the center of mass ($|\vec{k}^*|$) encode unique information on the
space-time structure of the emitting system. In addition to size of
the homogeneity region, analysis of correlation functions in the three-
dimensional $\vec{k}^*$ space can reveal a space-time offset of one
particle species (e.g. kaons) with respect...
Dr
Dilan Madagodahettige Don
(STAR (Creighton University))
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
Ultraperipheral collision events are effectively photoproduction on nuclear targets. These events provide an ideal proving ground for new programs in e+A physics. For the first time, STAR has collected a large enough sample of rho mesons to study their diffractive interaction with Au nuclear targets in detail. The transverse momentum distribution of rho mesons is sensitive not only to the...
Dr
Chin-Hao Chen
(PHENIX Collaboration)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Heavy flavor quarks such as charm and bottom, provide important probes of the parton energy loss mechanism in quark-gluon plasma. By studying the single electrons coming from the single leptonic decays of D and B mesons, we can study the energy loss of charm and bottom.
In order to study the heavy flavor energy loss process, a baseline comparison in p+p collisions where there is no...
Urs Wiedemann
(CERN)
16/08/2012, 16:00
Global and collective dynamics
Poster
We formulate the propagation of fluid dynamic fields as a propagation of small perturbations around smooth average fluid fields. Fluid dynamic simulations of smooth average initial conditions are then shown to be sufficient to map out the large space of fluid dynamic event histories resulting from arbitrary small fluctuations around these smooth initial conditions. We argue that this provides...
Patrick Simon Reichelt
(Johann-Wolfgang-Goethe Univ. (DE))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
The measurement of electron-positron pairs in the low invariant mass region allows to study the vacuum and in-medium properties of light vector mesons. Dielectrons also probe the production of thermal photons in heavy-ion collisions.
ALICE is well-suited to perform this measurement due to its excellent tracking and particle identification capabilities at very low momenta. However, Dalitz...
Dr
Zhi Qiu
(Ohio State University)
16/08/2012, 16:00
Global and collective dynamics
Poster
The Quark-Gluon Plasma (QGP) created in heavy-ion collisions is well described by viscous hydrodynamic simulations. A key QGP transport coefficient, its specific shear viscosity eta/s, can be extracted by comparing such simulations with experimental data. Previous extractions gave (eta/s)_QGP ~ (1-2.5)/(4\pi) where the ~100% uncertainty arises mainly from ambiguities in the initial fireball...
Yukinao Akamatsu
(Nagoya University)
16/08/2012, 16:00
New theoretical developments
Poster
Single heavy quark system has been considered as a hard probe for dynamical information of quark-gluon plasma (QGP), namely drag force, while heavy quarkonium has been thought to probe static information, such as heavy quark potential. However, this intuitive picture is not correct, in particular for the latter. Recent theoretical developments have shown that dynamical feature is also...
Kazuhiro Watanabe
(The University of Tokyo)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
We study the parton saturation effects on heavy quark production
in proton-nucleus collisions at collider energies, using the CGC
formula proposed by Blaizot-Gelis-Venugopalan (Nucl.Phys.A743:57-91,2004).
Previously it was numerically evaluated using the unintegrated
gluon distribution from the McLerran-Venugopalan model including
the x-evolution effect with the Balitsky-Kovchegov...
Huichao Song
(The Ohio State University)
16/08/2012, 16:00
Global and collective dynamics
Poster
Viscous hydrodynamic calculations have shown that the quark-gluon plasma (QGP) shear viscosity can be extracted from elliptic and triangular flow data [1]. However, strong non-equilibrium effects, both in the chemical composition and the kinetic evolution, during the hadronic stage influence the development and distribution of flow anisotropy and must be correctly accounted for when extracting...
Marzia Rosati
(Iowa State University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
The PHENIX collaboration is in the process of developing an ambitious upgrade plan (called sPHENIX) to significantly improve physics capabilities and make use of the full enhanced luminosity at RHIC. The sPHENIX design contains silicon tracking, electromagnetic and hadronic calorimetry with large kinematic coverage and high data rate capabilities to sample 50 billion Au+Au collisions...
Mr
Deke Sun
(Purdue University)
16/08/2012, 16:00
Jets
Poster
There has been a lot of interest in testing radiative energy loss
calculations against data from RHIC and the LHC. It is customary, as in the Gyulassy-Levai-Vitev (GLV) approach, to formulate the energy loss of a jet parton as a line integral from the production point along a straight-line trajectory. Calculations then account for variations in path length with jet origin and direction, and...
Boris Tomasik
(Univerzita Mateja Bela (SK))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
A Monte Carlo event generator REGGAE is presented which can generate momenta for given set of particles so that total energy and momentum assumes a pre-set value. The generator is proved to fill the available phase-space uniformly. In comparison to other algorithms it is considerably more effective in situations where many particles are produced and/or large part of the total energy is stored...
Prof.
Rolf Scharenberg
(Purdue University)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
The major challenge in heavy ion physics is to extract the equation of state and the shear viscosity to entropy ratio $\eta/s$ from the data. In the clustering of color sources (CSPM) the charged particle transverse momentum spectrum is used to measure the percolation density parameter $\xi$, which determines the initial temperature T, energy density $\epsilon$, and the $\eta/s$ ratio versus T...
Koichi Murase
(The University of Tokyo)
16/08/2012, 16:00
Global and collective dynamics
Poster
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 was that elliptic flow v_2
was comparable with an ideal hydrodynamic prediction and, as a result,
that a new paradigm of strongly...
Bikash Sinha
16/08/2012, 16:00
New theoretical developments
Poster
The conventional scenario to date of the quark hadron phase transition in the microsecond old universe is essentially guided by lattice calculation leading to a cross over from quarks to hadrons.
However, it is entirely possible that Affleck – Dine mechanism of baryogenesis leading to a large baryon asymmetry is more natural than in other models along the route baryogenesis via...
Martin Schulc
(Czech Technical University (CZ))
16/08/2012, 16:00
Jets
Poster
We perform (3+1)-dimensional ideal hydrodynamic calculation with source terms that describe energy and momentum deposition of hard partons in static quark-gluon plasma and study not only QGP response to one parton, but also interplay of perturbations due to two leading particles propagating in various directions. Energy deposition is described by a simple Bethe-Bloch model which leads to an...
385.
Results from Fixed-Target Collisions from STAR: Au+Al at $\root{S_{NN}}$ = 4.5, 3.5 and 3.0 GeV
Brooke Haag
(U)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
The RHIC Beam Energy Scan (BES) was proposed to search for the
possible critical point and to study the nature of the phase transition between hadronic and partonic matter.
However, several dynamical model simulations (UrQMD, PHSD,
QGSM, GiBUU, 3-fluid) suggest that the partonic phase is entered for
center-of-mass collision energies as low as 4-5 GeV [1]. Collisions
between beam halo...
Dr
Supriya Das
(Bose Institute)
16/08/2012, 16:00
Global and collective dynamics
Poster
Recent data from LHC has revived the question whether the matter produced in high energy hadronic collisions is thermalized or not. With the published data from ALICE and CMS experiments, we have shown that the multi-particle production in p+p collisions at LHC energies available up to now, follows the scaling of information entropy if one takes the chaotic and coherent sources of particle...
Giorgio Torrieri
(JW Goethe Universitat, Frankfurt)
16/08/2012, 16:00
Jets
Poster
In this talk we show that azimuthal harmonics of hard particles, thought to be generated via parton energy loss, should scale differently w.r.t. multiplicity and system size to azimuthal harmonics of soft particles, thought to be generated by hydrodynamic response.
By scanning harmonics in both energy and system size, we obtain a way of determining the domain of validity of...
Prof.
Fotis Diakonos
(University of Athens, Physics Department, Section of Nuclear and Elementary Particle Physics, GR-15771),
Nikolaos Davis
(University of Athens (GR))
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
We perform factorial moment analysis in the transverse
momentum space of protons produced at midrapidity in A+A collisions at the NA49 experiment (SPS, CERN). After background subtraction we find power-law dependence of the correlator on the number of phase space cells for the systems Si+Si and Pb+Pb at 158A GeV with large values of the associated characteristic
exponent (intermittency...
Michal Petran
(Czech Technical University (CZ))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
Soft hadron production at LHC energies presented a new challenge for the statistical hadronization mode (SHM). We show that the SHARE chemical nonequilibrium model describes well the available hadron yield data. We than extend SHARE to include CHARM contribution to hadron yields and present a remarkably accurate description of hadron yields at energy s_{NN} =2.76 TeV for several high ...
Dr
Nasser Demir
(Kuwait University)
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
We present a detailed comparison between two different methods to calculate
the shear viscosity coefficient for a set of four hadronic systems. One calculation
employs the Chapman-Enskog method to calculate the shear viscosity coefficient
for a hot hadronic system. The other calculation uses the Green-Kubo method
to calculate the shear viscosity for a hadronic medium simulated using
the...
Robert Lang
(TUM)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
Collision experiments with heavy ions at RHIC and CERN help to explore the nature of the deconfined quark-gluon phase. The matter created in such collisions behaves as an almost-perfect fluid indicated by very small dissipative effects. We use the two-flavor NJL model to approximate the QCD physics at high temperatures $T\gtrsim 200\,\text{MeV}$. A large-$N_c$ expansion is applied to include...
101.
Signature of liquid-gas phase transition and critical behavior in projectile multifragmentation
Ms
Rupalim Talukdar
(Department of Physics, Gauhati University, India)
16/08/2012, 16:00
Correlations and fluctuations
Poster
A high-statistics exclusive study of the multifragmentation of Mg-Em interaction at 4.5 AGeV has been performed to realize the critical behaviour. A number of relevant observables such as fluctuation in the sizes of the largest cluster, reduced variance and the mean value of second moment of charge distribution were estimated with the experimental data. The observed results are compared...
601.
Silicon pixel and strip detector development for the upgrade of the ALICE Inner Tracking System
Giacomo Contin
(Universita e INFN (IT))
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
The main physics motivation for the upgrade of the Inner Tracking System of the ALICE experiment is to perform new measurements on charm and beauty production in heavy-ion collisions, dealing with the challenge of expected Pb-Pb interaction rates of up to 50 kHz. For this purpose, a new silicon tracker is needed with greatly improved features in terms of determination of the distance of...
Jiayin Sun
(Stony Brook University)
16/08/2012, 16:00
Electroweak probes
Poster
Dielectron spectra in Au+Au collisions carry important information on the properties of the hot dense matter created in the early stage of the collisions. The earlier PHENIX measurement, using data taken in 2004 shows significant deviations from hadronic decay expectations. The most recent data set from 2010, taken with the the Hadron Blind Detector (HBD) upgrade designed to reduce the...
Nicole Apadula
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Since heavy flavor quarks are produced early in the collision, they experience the full evolution of the medium and are thus a good probe of medium effects. Electrons from open heavy flavor have previously been measured for p+p, Au+Au and d+Au collisions at the Relativistic Heavy Ion Collider (RHIC) by PHENIX. In the most central Au+Au the yield is suppressed relative to a Ncoll scaled p+p...
Mr
Raktim Abir
(Saha Institute of Nuclear Physics)
16/08/2012, 16:00
Jets
Poster
Most of the the calculations on gluon emission off a heavy quark, within perturbative QCD, have been performed in the literature using light cone gauge with eikonal approximations. Recently we revisited the issue in Feynman gauge that resulted in a very compact and elegant expression for the suppression factor for gluon emission off a heavy quark [1]. This generalization is valid for the full...
Dhevan Raja Gangadharan
(Ohio State University (US))
16/08/2012, 16:00
Correlations and fluctuations
Poster
Quantum coherence is fundamental in the interpretation of geometrical information from HBT measurements. The effect of quantum coherence is not only to lower the correlation strength of HBT correlations but also to modify the shape. We present measurements of the source chaoticity from Pb+Pb sqrt(s) = 2.76 TeV collisions at the LHC using the ALICE detector. Three-pion and two-pion correlations...
Björn Bäuchle
(FIAS Frankfurt)
16/08/2012, 16:00
Electroweak probes
Poster
Photons, as all electromagnetic probes, can give direct access to the hot and dense phase of a heavy-ion reaction. We show calculations of direct photon emission at highest energies available with the UrQMD-hybrid model. UrQMD is a full microscopic+macroscopic transport/fluiddynamics hybrid model with hadron- and string-driven equilibration phase, a fll (3+1)-dimensional fluiddynamic hot and...
Prof.
Sanjay Ghosh
(Bose Institute)
16/08/2012, 16:00
Global and collective dynamics
Poster
Collective flow is an essential component in describing the
dynamics of relativistic heavy ion collisions. The flow characteristics are intimately related to the equation of state of the thermally equilibrated matter created in these collisions through the speed of sound. Using either the Bjorken or Landau hydrodynamics or a combination thereof it is possible to relate the
particle yields to...
Anne Sickles
(Brookhaven)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Prof.
Jamie Nagle
(University of Colorado)
16/08/2012, 16:00
Jets
Poster
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)....
Dr
Hiroshi Masui
(LBNL)
16/08/2012, 16:00
Global and collective dynamics
Poster
Elliptic flow $v_2$ is one of the key observables to study the bulk properties at freeze-out as well as hadron production mechanisms in the ultra relativistic heavy ion collisions. It has been observed that number of constituent quark (NCQ) scaling of $v_2$ holds among measured identified hadrons at $\sqrt{s_{NN}}$ = 62.4 and 200 GeV in Au + Au collisions at RHIC. The scaling of $v_2$ strongly...
Cesar Luiz da Silva
(L)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
The Forward Vertex Detector (FVTX) was installed in PHENIX this year
and operated during the $\sqrt{s}=$510 GeV $p$+$p$,
$\sqrt{s_{NN}}=$193 GeV U+U, and $\sqrt{s_{NN}}=$200 GeV Cu+Au
runs. The FVTX has full azimuthal coverage between 1.2$<|y|<$2.2 and
consists of 4 stations with 2 planes of silicon mini-strips with 75 $\mu$m pitch in the
radial direction and 96 azimuthal segments. The...
Bikash Sinha
16/08/2012, 16:00
New theoretical developments
Poster
The universe is assumed to begin with a large baryonic chemical potential acquired through an Affleck – Dine mechanism, which leads on to a baryon asymmetry of 0(1) without requiring superhigh temperatures. However, the observed baryon asymmetry of 0(10-10) at CMB temperature needs to emerge naturally from such a scenario. This is what could be achieved through a “little inflation” of about 7...
Sener Ozonder
(University of Minnesota)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
We consider a modified version of the McLerran-Venugopalan model where the thickness of the nucleus is finite and infrared divergences are removed by the color neutrality condition. The strong coupling constant and the nucleon size are treated as parameters. To determine these parameters, the x-dependent gluon distribution function is calculated at very low momentum, which is the region of...
Laura Patel
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Production of open bottom (B) mesons is an important tool to probe the hot and dense matter created from nucleus-nucleus collisions at the Relativistic Heavy Ion Collider (RHIC). In the mass region between 4.5 and 12 GeV, the only source of correlated like-sign dimuons will come from the semileptonic decay of B meson pairs. The number of correlated like-sign dimuons due to neutral B meson...
Bhanu Sharma
(Panjab University)
16/08/2012, 16:00
Correlations and fluctuations
Poster
The STAR experiment at Relativistic Heavy Ion Collider (RHIC) investigates the behaviour of strongly interacting matter at high density and searches for the possible formation of Quark Gluon Plasma (QGP). Event-by-event net charge fluctuation has been proposed as one of the indicators of QGP formation in heavy ion collisions. The fluctuation in net charge depends on the squares of the charges...
Ms
Neha Shah
(University of California Los Angeles)
16/08/2012, 16:00
Correlations and fluctuations
Poster
The production of large number of multi-strange hyperons per central nucleus-nucleus collision at RHIC allows us to study hyperon-hyperon interactions through measurement of particle correlations and search for exotic particles like dihyperons. In 1977 Jaffe[1] predicted a six quark state, $H_{0}$-dibaryon, with hypercharge (Y) = 0 and Strangeness (S) = -2 to be stable against strong decay,...
Sanshiro for the PHENIX experiments Mizuno
(University of Tsukuba, RIKEN (JP))
16/08/2012, 16:00
Global and collective dynamics
Poster
Azimuthal anisotropy and particle species dependence of transverse momentum distribution have been studied actively because they reveal information about the QGP generated in high energy heavy ion collisions.
From the study of elliptic event anisotropy v_{2}, we have understood that azimuthal anisotropy is generated by initial participant geometry, with a role for the QGP property $\eta$/s...
Dr
Kun Liu
(Los Alamos National Laboratory)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
E906/SeaQuest is a fixed-target experiment operated at Fermi National Accelerator Laboratory. Using the 120 GeV proton beams from the Main Injector, E906/SeaQuest measures the Drell-Yan production in the dimuon mass region of 4-8 GeV in p+p and p+A collisions over a wide xF range. Parton energy loss in QGP is considered as the dominant mechanism of the observed jet-quenching phenomena at RHIC...
Tinku Sarkar - Sinha
(Saha Institute of Nuclear Physics (IN))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
The high energy density reached in pp collisions at LHC could be comparable with the energy density for heavy–ion collisions at lower energies (i.e. Au-Au collisions at RHIC) and it might lead to the observation of collective phenomena. The multiplicity of the collision can be used as the “centrality” variable in pp collisions at LHC.
In particular, the LHC provided p-p collisions at √s =...
Min Jung Kweon
(Ruprecht-Karls-Universitaet Heidelberg (DE))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Heavy quarks are expected to be a probe providing new constraints on partonic energy loss mechanisms in the medium produced in heavy-ion collisions at the LHC. In particular, the medium-induced parton energy loss is expected to depend on its mass and colour charge. The measurement of heavy quark production in pp collisions provides an important test of pQCD calculations and serves as a...
Tomas Aronsson
(Yale University (US))
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
High-energy heavy-ion collisions at the LHC allow for the study of the properties of the quark-gluon plasma (QGP). Heavy quarks, charm and bottom, produced in the initial hard scattering processes of the collision are excellent probes of the QGP.
When heavy quarks traverse the QGP they are expected to lose energy and such energy loss is predicted to be smaller than for gluons and light...
Dr
Umme Jamil Begum
(Debraj Roy College, Golaghat, Assam, India)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
Charm quarks/antiquarks produced in the initial stage of heavy ion collisions, would traverse the quark gluon plasma, colliding with quarks and gluons and radiating gluons before appearing as D-mesons. Thus the final spectra of D-mesons would contain information of the medium modification suffered by the charm quarks/antiquarks. We have made a detailed study for the nuclear modification factor...
Sooraj Krishnan Radhakrishnan
(State University of New York (US))
16/08/2012, 16:00
Global and collective dynamics
Poster
The anisotropy associated with the initial dipole asymmetry in heavy ion collisions is studied via the first harmonic coefficient $v_{1,1}$ of the two-particle azimuthal angle correlations, within AMPT and HIJING model (AMPT is essentially HIJING + parton/hadron transport). For a broad selection of centrality, transverse momenta and pseudorapidity ($\eta$), a fitting method is used to...
Mr
Dustin Hemphill
(Purdue University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Dr
Hanzhong Zhang
(Institute of Particle Physics, Central China Normal University)
16/08/2012, 16:00
Jets
Poster
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...
Jinfeng Liao
(Indiana University & RIKEN BNL Research Center)
16/08/2012, 16:00
New theoretical developments
Poster
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...
Mr
Hiroshi Nakagomi
(Univ. of Tsukuba)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Michael Winn
(Ruprecht-Karls-Universitaet Heidelberg (DE))
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Matthew Lamont
(BNL)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Tobias Tischler
(Goethe-Universität, Frankfurt)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
J. Matthew Durham
(Los Alamos National Laboratory)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Jan Kopfer
(Universität Wuppertal)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Sourendu Gupta
(Tata Institute of Fundamental Research)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
298.
The Tungsten-Scintillating Fiber Accordion Electromagnetic Calorimeter for the sPHENIX Detector
Dr
Craig Woody
(Brookhaven National Lab)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Dr
Song Shu
(Faculty of Physics and Electronic Technology, Hubei University, China)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Bikash Sinha
16/08/2012, 16:00
New theoretical developments
Poster
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...
Gergely Barnafoldi
(Hungarian Academy of Sciences (HU))
16/08/2012, 16:00
Jets
Poster
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...
Giorgio Torrieri
(JW Goethe Universitat, Frankfurt)
16/08/2012, 16:00
Jets
Poster
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...
Prof.
Angel Gomez Nicola
(Universidad Complutense Madrid)
16/08/2012, 16:00
QCD at finite temperature and density
Poster
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...
Chun Shen
(Ohio State University)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Dr
Gabor David
(Brookhaven National Laboratory)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Dr
Bhaswar Chatterjee
(Physical Research Laboratory, Ahmedabad, India)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Richard Petti
(S)
16/08/2012, 16:00
Electroweak probes
Poster
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....
Takahiro Sasaki
(K)
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Jason Glyndwr Ulery
(Johann-Wolfgang-Goethe Univ. (DE))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Mate Csanad
16/08/2012, 16:00
Exploring the QCD phase diagram
Poster
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...
Bin Zhang
(Arkansas State University)
16/08/2012, 16:00
Pre-equilibrium and initial state dynamics
Poster
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...
Jorge Noronha
(U)
16/08/2012, 16:00
New theoretical developments
Poster
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...
Ioannis Bouras
(University of Frankfurt a.M.)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Anton Wiranata
(L)
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
Claude Andre Pruneau
(Department of Physics and Astronomy)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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,...
Marton Vargyas
(ELTE)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Piotr Bozek
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Laszlo Pal Csernai
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Theodore Koblesky Theo
(University of Colorado)
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Mr
Jingbo Wang
(Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Beijing 100084, China)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Jai Salzwedel
(Ohio State University (US))
16/08/2012, 16:00
Correlations and fluctuations
Poster
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...
Elizabeth Oldag
(UT Austin, STAR Collaboration)
16/08/2012, 16:00
Jets
Poster
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...
Andrew Marshall Adare
(Yale University (US))
16/08/2012, 16:00
Jets
Poster
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...
Prof.
Seto Richard
(University of California, Riverside)
16/08/2012, 16:00
Experiment upgrades, new facilities, and instrumentation
Poster
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...
Georg Wolschin
(Heidelberg University)
16/08/2012, 16:00
Heavy flavor and quarkonium production
Poster
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...
Ms
P S Saumia
(Institute of Physics)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Mr
Manuel Lorenz
(Goethe University Frankfurt)
16/08/2012, 16:00
Electroweak probes
Poster
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...
Mr
Zachary Wolff
(Purdue University)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Jacquelyn Noronha-Hostler
(U)
16/08/2012, 16:00
Global and collective dynamics
Poster
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...
Michael Tannenbaum
(Brookhaven National Laboratory (US))
16/08/2012, 16:00
Global and collective dynamics
Poster
\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...
Boris Tomasik
(Univerzita Mateja Bela (SK))
16/08/2012, 16:00
Hadron thermodynamics and chemistry
Poster
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...
