Participant (Inst.) Week (Period of stay) | Weeks | Title (type) Abstract |
---|---|---|
Gert Aarts (Swansea) 2,3(11-26 -- 12-08) | -oo-- | "Bottomonium and transport in the QGP" [Hard/PD] "Complex Langevin dynamics: distributions and gauge theories" I can talk either about Bottomonium in the QGP combined with transport (electrical conductivity) or about Complex Langevin simulations at nonzero density. |
Yukinao Akamatsu (KMI, Nagoya) 4(12-09 -- 12-12) | ---o- | "In-medium QCD forces for heavy quarks at high temperature" [Hard] Real-time processes of heavy quark systems have attracted interests since they can probe medium properties of quark-gluon plasma (QGP). At relativistic heavy-ion collision experiments at RHIC and LHC, heavy quark signals have given us insights on the medium properties such as drag force and color screening in the QGP. In this talk, I will concentrate on quantum aspects of the heavy quark real-time dynamics. Based on the closed-time path formalism, I will derive master equations for the heavy quark systems in the leading-order perturbative expansion. These master equations describe interaction of a heavy quark with medium particles and also with another heavy quark. The former gives a quantum description of the Langevin dynamics and the latter gives the Debye screening potential between the color charges. The relation to the stochastic potential approach is also discussed. |
Yasuyuki Akiba (RIKEN) 3(12-02 -- 12-06) | --o-- | |
Kenji Araki (TITech) 3(12-02 -- 12-06) | --o-- | "QCD sum rules on the complex plane and analyses by MEM" [Poster] We formulate the QCD sum rule on the complex q^2 plane. It was found that we can use more information about the spectral functions of hadrons than the standard real-value sum rules. Then we obtain reliable predictions on the spectral functions by the Maximum Entropy Method (MEM) analyses. We will report some of the physical results. |
Masayuki Asakawa (Osaka) 1,2,3,4,5(11/18-11/20,11/25-11/27,12/2-12/6,12/9-12/11,12/16-12/18) | ooooo | "Center Domains and Their Phenomenological Consequences" [Col.] We argue that the domain structure of deconfined QCD matter, which can be inferred from the properties of the Polyakov loop, can simultaneously explain the two most prominent experimentally verified features of the quark-gluon plasma, namely its large opacity as well as its near ideal fluid properties. |
Maximilian Attems (FIAS) 2,3(11-24 -- 12-06) | -oo-- | "Realtime fermions in an anisotropic plasma" [Col.] The “standard model” of relativistic heavy-ion collisions describes the hadronic collission first by Lorentz contracted sheets of hadrons the so called Color Glass Condensate. The study of anisotropically expanding plasmas shows that non-Abelian plasmas isotropize fast enough thanks to the Chromo-Weibel instability. Recent work involves the novel incorporation of fermions in the Yang-Mills evolution of this QCD system. |
Steffen A. Bass (Duke) 3,4(12-03 -- 12-10) | --oo- | "Heavy Quark Dynamics in the QGP" [Hard] Over the past year our group has studied heavy quark energy loss in the context of a Langevin approach. Main emphasis of our study was the question of heavy quark thermalization in a QGP medium as well as the dependence of the most common observables associated with heavy quark energy loss (R_AA and v_2) on various parameters of the medium evolution, to which our Langevin approach is coupled. Here, in addition to reviewing the results of the aforementioned studies, we will introduce an algorithm that incorporates the radiative energy loss of heavy quarks in a QGP medium into the current Langevin framework by treating gluon radiation as an additional force to the heavy quarks traversing the medium. We examine the corresponding effects on observables such as the elliptic flow and the nuclear modification factor, and compare our simulations to the experimental results at the LHC. Our study constitutes an essential contribution to a more quantitative understanding of the energy loss of heavy quarks propagating through hot and dense nuclear medium. |
Sanjin Benic (Zagreb) 1,2,3(11-18 -- 12-06) | ooo-- | "Non-local chiral quark models in medium - a case study" [PD] We show that covariant effective chiral quark models are in general thermodynamically unstable. This is an imprint of the confining property of the quark propagator. By calculating the Equation of State this problem is explicitly demonstrated. We find that instability is much reduced when the quarks are coupled to the Polyakov loop. By analyzing the analytic properties of the quark-antiquark polarization loop, we provide qualitative features of the meson dissociation in these models. We find that the meson width is surprisingly sensitive to the particular way a non-local interactions between the bound state constituents is imposed. |
Juergen Berges (Heidelberg) 3,4(12-01 -- 12-13) | --oo- | "Turbulent Thermalization" [IC/pre] |
Barbara Betz (Frankfurt) 3,4(12-05 – 12-13) | --oo- | "Azimuthal Jet Tomography at RHIC and LHC" [Hard] Recent data on the azimuthal and transverse momentum dependence of high-pT pion nuclear modification factors in nuclear collisions at RHIC and LHC are analyzed in terms of a wide class of jet-energy loss models, ranging from running coupling pQCD based prescriptions to AdS/CFT-inspired models, considering a variety of transverse expanding collective flow backgrounds. RHIC data are found to be surprisingly consistent with rather different dE/dx models. However, extrapolations to LHC favor running coupling QCD based energy-loss models over fixed coupling QCD, conformal AdS holography, or Tc-dominated jet-energy loss models that tend to overpredict jet quenching at the LHC. |
Jean-Paul Blaizot (Saclay) 2,3,4(11-29 -- 12-12) | -ooo- | "Jets in quark-gluon plasmas" [Hard] |
Nicolas Borghini (Bielefeld) 3(12-01 -- 12-07) | --o-- | "Dissipative corrections to anisotropic flow" [Col.] A dissipative fluid emits particles differently from an ideal one. In the limit of a low freeze-out temperature, the difference mostly affects particles with a higher velocity than the fluid. I shall show how this feature may be exploited to constrain the transport coefficients of the fluid at freeze-out by using several one- and multiparticle observables at once. |
Michael Buballa (Darmstadt) 1,2(11-18 -- 11-28) | oo--- | "Inhomogeneous phases in strong-interaction physics" [PD] Most studies of the QCD phase diagram tacitly assume that the different phases are homogeneous in space. However, there are good arguments that inhomogeneous phases could also be present. In this talk I focus on inhomogeneous chiral-symmetry breaking phases, where the quark condensate varies in space. Model calculations suggest that the first-order chiral phase transition, including the critical endpoint, could be removed from the phase diagram when inhomogeneous phases are included. More recently similar results have also been obtained from Dyson-Schwinger studies of QCD. |
Sergio Calle Jimenez (TITech) 1,2(11-18 -- 11-29) | oo--- | |
Stefano Carignano (Texas, El Paso) 1,2(11-18 -- 11-29) | oo--- | "Inhomogeneous phases in the Quark-Meson model" [PD] I will present some recent developments in the study of inhomogeneous chiral symmetry breaking phases |
Gabriel Silveira Denicol (McGill) 2,3(11-25 -- 12-06) | -oo-- | "Extracting the bulk viscosity of the quark-gluon plasma" [Col.] Currently, most fluid-dynamical simulations of relativistic heavy ion collisions take into account only the effect of shear viscosity. However, in principle there is no reason to neglect bulk viscosity since the actual order of magnitude and temperature dependence of this transport coefficient is just unknown, and could be significant. In this work, we attempt to extract the order of magnitude of bulk viscosity using the data from ultracentral heavy ion collisions performed at the LHC. For this purpose we include all possible second order terms that appear in Israel-Stewart theory, including those that couple bulk viscous pressure to shear stress. The transport coefficients of all terms are computed using kinetic theory. |
Heng-Tong Ding (CCNU) 2,3(11-25 -- 12-06) | -oo-- | "QCD transition at finite temperature with Domain Wall fermions" [PD] We present recent studies on the fate of chiral and axial symmetries at finite temperature in 2+1 flavor QCD using Domain Wall fermions having lattice spacings corresponding to the temporal extent of Nt=8 and various volumes. Domain Wall fermions is a realization of chiral fermions on the lattice that preserves the exact chiral symmetry and reproduces the correct axial anomaly even at a finite lattice cutoff. We investigate the nature of QCD transition by performing calculations with two pion masses, namely with a physical pion mass and also with a slightly heavier pion mass of 200 MeV. We explore the restoration of chiral and axial symmetries at finite temperature by studying the relationships among various appropriate susceptibilities. We also investigate the role of Dirac eigenvalue spectrum in understanding the underlying mechanism of the axial symmetry breaking in the chirally restored phase. We also present comparisons of various observables with those using non-chiral fermions namely Highly Improved Staggered Quarks. |
Adrian Dumitru (Baruch College) 3,4(12-02 -- 12-13) | --oo- | "Spatial Wilson loops and domains at the initial time in heavy-ion collisions" [IC/pre] |
Shinji Ejiri (Niigata) 1,2,3(11-18 -- 12-06) | ooo-- | "Nature of QCD phase transition at finite temperature and density" [PD] Because the quark determinant is a complex number at finite density, the Monte-Carlo method cannot be applied directly. Among methods to avoid the problem of the complex determinant, we explain a reweighting method focusing on probability distribution functions. We try to solve the problems which arise in the finite density QCD, i.e. the sign problem and the overlap problem, using this method. After discussing general properties of the probability distribution function, we investigate the critical point which separates the first order transition and crossover, expected in the high density region. |
Gergely Fejos (RIKEN) 3(12-02 – 12-06) | --o-- | "Chiral symmetry breaking patterns in the U(n)xU(n) meson model" [PD] Chiral symmetry breaking patterns are investigated in the U(n)xU(n) meson model. It is shown that new classes of minima of the effective potential belonging to the center of the Lie algebra exist for arbitrary flavor number n. The true ground state of the system is searched nonperturbatively and although multiple local minima of the effective potential may exist, it is argued that in regions of the parameter space applicable for the strong interaction, strictly a U_L(n)xU_R(n)->U_V(n) spontaneous symmetry breaking is possible. The reason behind this is the existence of a discrete subset of axial symmetries, which connects various U_V(n) symmetric vacua of the theory. The results are in agreement with the Vafa-Witten theorem of QCD, illustrating that it remains valid, even without gauge fields, for an effective model of the strong interaction. |
Efrain J. Ferrer (Texas, El Paso) 1(11-18 -- 11-22) | o---- | "Induced Magnetic Moment in Effective Models of Quarks" [PD] I will discuss the simultaneous generation of a chiral condensate and a dynamical anomalous magnetic moment (AMM) in a magnetized quark system in the context of a one-flavor Nambu-Jona-Lasinio model. It will be explained how once a magnetic field induces a chiral condensate, the AMM is inevitably generated and no pion condensate is allowed. The presence of the induced AMM reinforces the amplitude of the chiral condensate. I will also show how the behavior of the critical temperature with the field can reproduce recent lattice QCD findings by assuming that the coupling runs with the magnetic field in a way that is compatible with QCD results. |
Christian S. Fischer (Giessen) 2,3(11-26 -- 12-05) | -oo-- | "QCD phase diagram in the Dyson-Schwinger approach" [PD] I review recent progress on the location of the chiral and deconfinement phase transitions of QCD using functional approaches. In particular I will focus on the potential location of the critical end point, the properties of quarks and gluons in the different phase and the determination of the Polyakov loop potential. |
Rainer Joachim Fries (Texas A&M) 3(12-02 – 12-06) | --o-- | "Flow and Energy Momentum Tensor from Classical Gluon Fields" [IC/pre] The McLerran-Venugopalan (MV) realization of the color glass condensate in high energy nuclei predicts strong longitudinal gluon fields when two such nuclei collide. From these longitudinal fields transverse fields emerge due to the non-abelian analogues of Gauss', Faraday's and Ampere's Laws. The Poynting vector associated with these field configurations has some intriguing features. E.g., despite the boost-invariant setup of the MV model, rapidity-odd transverse flow fields are realized in classical QCD. This is interesting since rapidity-odd flow is often neglected in boost-invariant or near-boost-invariant simulations of the fireball (e.g. in hydrodynamics). The rapidity-odd gluon energy flow can eventually lead to phenomena like directed flow of particles, angular momentum of the fireball, and novel flow signatures in asymmetric A+B collisions. We will use analytic solutions to the MV glasma energy momentum tensor to describe these flow phenomena. We will then show how these results can be used to constrain initial conditions for viscous hydrodynamics, and discuss how hydrodynamics propagates signatures of the glasma flow through the fireball evolution. |
Hirotsugu Fujii (Tokyo) 2,3,4,5(11-25 -- 12-20) | -oooo | "Heavy quarks from CGC in pA collisions" [IC/pre] |
RYUTARO Fukuda (Keio) 1,2,3(11-18 -- 12-06) | ooo-- | |
Kenji Fukushima (Tokyo) 1,2(11-18 -- 11-25) | oo--- | |
Charles Gale (McGill) 3,4(11-30 -- 12-11) | --oo- | "Photons and Dileptons from Heavy-Ion Collisions and QCD: Microscopic and Bulk Dynamics" [Hard] Electromagnetic radiation constitutes a class of penetrating probes that travel unscathed from their formation site to the detectors. We review the progress made in calculating the photon and dilepton production rates from hot and dense matter, as well as the progress in integrating those rates in time-dependent models of the collision. We discuss the prospects of extracting fundamental quantities which may be used to characterize the behaviour of QCD, in and out of equilibrium. |
Francois Gelis (Saclay) 3,4,5(12-03 -- 12-20) | --ooo | "Isotropization in Heavy Ion Collisions at High Energy" [IC/pre] I will present ongoing work whose purpose is to understand the early dynamics of the gluonic matter produced in ultra-relativistic heavy ion collisions. |
Soichiro Goda (Kyoto) 1,2,3,4,5(11-18 -- 12-20) | ooooo | |
Vincenzo Greco (Catania) 3(12-02 -- 12-06) | --o-- | "Anisotropic flows in a Boltzmann kinetic approach at fixed eta/s(T)" [Col.] The Relativistic Heavy-Ion program has shown that a key properties of the QGP is its very low shear viscosity to density entropy ratio η/s(T). A key observable is supplied by the different harmonics of the collective flows vn(pT). We present a transport approach, developed with η/s(T) as an external parameter similarly to the hydrodynamical approach, able to naturally describe the vn(pT) in a wide range of pT and η/s(T) (including the rise and fall observed at LHC). Furthermore kinetic theory allows to implement properly the non-equilibrium Color Glass Condensate conditions determined by the QS saturation scale. We find that there can be a large compensation in the build up of v2(pT) between the initial large space eccentricity and the damping due to the initial non-equilibrium We will show, exploring the T dependence of η/s(T), that a study of vn allows to understand the difference behind the build of collective flows from low energy scan at RHIC to LHC energies and in particular the relevance of the QGP phase. |
Philipp Gubler (RIKEN) 3,4(12-02 – 12-13) | --oo- | "Quarkonia at finite T from QCD sum rules and MEM" [Hard] The present status of QCD sum rule studies on quarkonia at finite temperature will be reviewed and their results compared with those obtained from lattice QCD. Issues that need to be tackled in the future for improving the QCD sum rule method will also be discussed. |
Miklos Gyulassy (Columbia) 2,3,4(11-27 -- 12-13) | -ooo- | "Jet Flavor Probes of QGP at RHIC and LHC" [Hard] Recent RHIC and LHC jet quenching data challenge both pQCD and hQCD p[aradigms for jet quenching. Current work using the running coupling CUJET2.0 = DGLV + VISH (J.Xu, MG,A.Buzzatti)) to predict u,c,b quark jet observables will be reviewed and compared to generic (abc) powerlaw energy loss models (Betz , MG). Recent progress based on non-conformal and higher derivative 5D deformed AdS holographic models (Ficnar, Gubser, MGl) of jet quenching will also be compared to data. Most critical observables currently are the jet flavor, pT, and centrality dependence of RAAin and RAAout. |
Tetsuo Hatsuda (RIKEN) 3(3rd week) | --o-- | "Dense QCD and Compact Stars" [Overview] |
Yoshitaka Hatta (YITP) 1,2,3,4,5(11-18 -- 12-20) | ooooo | |
Koichi Hattori (Yonsei) 3,4,5(12-02 -- 12-20) | --ooo | "Anisotropic dilepton spectrum induced by chiral anomaly in strong magnetic fields" [Hard] In the presence of strong magnetic fields such as created in ultrarelativistic heavy ion collisions, transition between a neutral pion and a virtual photon becomes possible through the triangle diagram relevant for the chiral anomaly. We show that the decay mode of a neutral pion into two photons cannot persist in the dominant mode in strong magnetic fields, and that decay into a dilepton instead dominates over the other modes. We also show the effects of magnetic fields on prompt virtual photons created in ultrarelativistic heavy-ion collisions. There is no anisotropy in the spectrum at the stage of creation of prompt virtual photons, but after traversing the strong magnetic field that is induced perpendicularly to the reaction plane, virtual photons turn into neutral pions, leading to an anisotropic spectrum of dileptons as a feasible signature in the measurement. ``Neutral-pion reactions induced by chiral anomaly in strong magnetic fields'', K. Hattori, K. Itakura and S. Ozaki, [arXiv:hep-ph:1305.7224]. |
Tomoya Hayata (Tokyo) 3(12-02 -- 12-06) | --o-- | "Temporal Chiral Spiral in Strong Magnetic Fields" [PD] We discuss the QCD vacuum with time-dependent chiral condensate in strong magnetic and finite electric fields. We show that when a uniform electric field is instantaneously applied in the parallel direction to a strong magnetic field, it induces temporal oscillation of the chiral and pion condensates in a spiral form, which we call the "temporal chiral spiral". The temporal chiral spiral originates with the propagation of the chiral magnetic wave, which is protected by the axial anomaly and thus non dissipative. Reference:arXiv:1309.0012 |
Ulrich Heinz (Ohio) 3,4(12-01 – 12-12) | --oo- | "The Little Bang Standard Model" [Col.] The Little Bangs created in ultra-relativistic heavy-ion collisions share many characteristic features with the cosmological evolution after the Big Bang. I will demonstrate how quantum fluctuations in the initial state of the Little Bang propagate via hydrodynamic evolution (supplemented by an early pre-equilibrated thermalization and a late kinetic freeze-out stage) into the experimentally observed final state, manifesting themselves as fluctuations in the final flow pattern. A harmonic analysis of the final flows, their transverse momentum dependence and their flow angles (the "Little Bang flow fluctuation spectrum") provides detailed information from which the spectrum of gluon fluctuations in the initial state and the transport coefficients of the quark-gluon plasma fluid created in the collisions can be quantitatively extracted. |
Yoshimasa Hidaka (RIKEN) 2,3,4(11-29 -- 12-09) | -ooo- | "Vector mesons in a strong magnetic field" [PD] We discuss charged vector mesons in a strong magnetic field. We show that the charged vector mesons cannot be condensed by a magnetic field. We perform the numerical analysis for the meson mass and condensation in lattice QCD. We also discuss the relation between our result and previous works that showed the vector meson condensation. |
Tetsufumi Hirano (Sophia) 1,2,3(11-21 -- 12-06) | ooo-- | "Fluctuations in relativistic hydrodynamics" |
Masaru Hongo (Tokyo) 1,2,3,4,5(11-18 -- 12-20) | ooooo | "Anomalous hydrodynamic simulation and charge-dependent elliptic flow" [Col.] Anomalous hydrodynamics is a low-energy effective theory that captures effects of quantum anomalies. We develop a numerical code of anomalous hydrodynamics and apply it to dynamics of heavy-ion collisions, where anomalous transports are expected to occur. This is the first attempt to perform fully non-linear numerical simulations of anomalous hydrodynamics. We discuss implications of the simulations for possible experimental observations of anomalous transport effects. From analyses of the charge-dependent elliptic flow parameters (v2±) as a function of the net charge asymmetry A±, we quantitatively verify that the linear dependence of Δv2 ≡ v2(-)-v2(+) on the net charge asymmetry A± cannot be regarded as a sensitive signal of anomalous transports, contrary to previous studies. We, however, find that the intercept Δv2(A± = 0) is sensitive to anomalous transport effects. |
Defu Hou (CCNU) 1,2,3(11-18 -- 12-06) | ooo-- | "Sub-leading order heavy quark potential and jet quenching parameter from AdS/CFT" [PD] I will talk about recent progress on the subleading order corrections to the heavy-quark potential and jet quenching parameter from AdS/CFT. |
Huan Zhong Huang (UCLA) 3(12-02 – 12-05) | --o-- | "STAR Heavy Ion Physics Program and Future Perspective" [PD(Exp.)] |
Pasi Huovinen (FIAS) 1(11-18 -- 11-22) | o---- | "Dynamical freeze-out in event-by-event hydrodynamics" [Col.] |
Tetsuo Hyodo (YITP) 1,2,3,4,5(11-18 -- 12-20) | ooooo | |
Terukazu Ichihara (YITP) 1,2,3(11-18 -- 12-06) | ooo-- | "QCD phase diagram at strong coupling with fluctuations" [PD] We study the QCD phase diagram with meson fluctuations based on strong coupling lattice QCD, using unrooted staggered fermions. In order to consider the fluctuation effects, we integrate out auxiliary meson fields by Monte Carlo technique so-called auxiliary field Monte-Carlo (AFMC) method. We show the QCD phase transition in AFMC method, and compare our results with those in MDP simulations. In the MC integration, we have the sign problem, which leads to lower reliability in numerical simulations. We also discuss how the sign problem arises in our method, and the possibility to perform simulations for a larger lattice. |
Yuji Igarashi (Niigata) 3(12-02 -- 12-06) | --o-- | |
Hideaki Iida (Kyoto) 1,2,3,4,5(11-18 -- 12-20) | ooooo | "Thermalization and entropy production from Glasma initial condition in classical Yang-Mills dynamics" [IC/pre] Thermalization process in classical Yang-Mills (CYM) field theory starting from noisy glasma-like initial conditions is studied by investigating the initial-value sensitivity of trajectories. The Kolmogorov-Sinai (KS) entropy, which gives the entropy production rate in classical chaotic system, is calculated numerically for CYM fields starting from glasma-like initial conditions with and without fluctuations. For small random fluctuations we observe initial-value sensitivity of the system, while no sensitivity is observed without fluctuations. We analyze the intermediate time Lyapunov spectrum for several time windows and calculate KS entropy defined by the sum of positive Lyapunov exponents. We find a large number of positive Lyapunov exponents at the early stages of time evolution. Also for later times their number is a sizeable fraction of the total number of degrees of freedom. Thus we conclude that for glasma-like initial conditions a significant amount of entropy is produced by classical gluon field dynamics. We also discuss the creation of decoherence entropy caused by the loss of coherence of quantum states in the initial stage of heavy-ion collisions. |
Atsuro Ikeda (Osaka) 3(12-02 -- 12-06) | --o-- | "Charm quark diffusion constant and relaxation time in the deconfined phase in quenched lattice QCD" [Hard] We examine the charm quark diffusion constant and relaxation time in the deconfined phase using Euclidean correlators obtained with the quenched lattice and the relaxation time approximation, in which the low energy structure of the spectral function is given the Breit-Wigner form. We assume the structure of the spectral function including three parameters, relaxation time, diffusion constant and the finite temperature effect on the decrease of the charmonium spectral weight, and evaluate these parameters by fitting the difference between finite temperature and reconstructed correlators from lattice QCD. |
Vivian Incera (Texas, El Paso) 1(11-18 – 11-22) | o---- | "Chiral spirals vs Crystalline P-H Ground States" [PD] I will discuss the formation of an inhomogeneous ground state in a QCD-inspired NJL model at intermediate densities, showing that the most favored single-modulated solution at intermediate densities may not be a crystalline one, as claimed in previous studies, but the chiral spiral. Comparison with existing QCD-like models and the potential for observational signals in future experiments will be outlined. |
Masahiro Ishii (Kyushu) 3(12-02 -- 12-06) | --o-- | |
Kazunori Itakura (KEK) 3,4(12-02 -- 12-13) | --oo- | |
Katsumi Itoh (Niigata) 3(12-02 -- 12-06) | --o-- | |
Ryo Iwami (Niigata) 3(12-02 -- 12-06) | --o-- | "TBD" [Poster] |
Aiichi Iwazaki (Nishogakusha) 3(12-02 -- 12-05) | --o-- | "Monopole production and rapid decay of gauge fields" [IC/pre] It has been argued that the rapid decay of coherent color gauge fields generated immediately after high energy heavy ion collisions produces quark gluon plasma. But there are no convincing mechanisms for the rapid decay of the gauge fields which satisfy phenomenological constraints on their life time. We show that the production of magnetic monopoles causes the rapid decay of the gauge fields. The monopoles are unstable modes just like Nielsen-Olesen modes and are enormously produced by dual Schwinger mechanism. |
Jiangyong Jia (Stony Brook / BNL) 3(12-01 -- 12-07) | --o-- | "Event by Event flow at LHC and event-shape-selection technique" [Col.] |
Kazuhiko Kamikado (RIKEN) 2(11-25 -- 11-29) | -o--- | |
Takuya Kanazawa (RIKEN) 1(11-18 -- 11-22) | o---- | |
Frithjof Karsch (Bielefeld / BNL) 2,3(11-24 -- 12-07) | -oo-- | "Exploring the QCD phase diagram with conserved charge fluctuations" [PD] |
Taekwang Kim (Osaka) 3(12-02 -- 12-06) | --o-- | "Production Rates of Dileptons Constructed from a Non-Perturbative Quark Propagator" [Hard] We analyze non-perturbative effects on the production rate of dileptons from the deconfined medium. For this purpose, we use a non-perturbative quark propagator, which is taken by lattice QCD numerical simulation. The vertex correction is determined so as to satisfy the Ward identity required by gauge invariance. We calculate the production rate of dileptons from the strongly coupled quark-gluon plasma by these propagator and vertex, and evaluate the contribution from the quark-gluon plasma to the production yield of dileptons, which is measured in high-energy heavy ion collisions. |
Masakiyo Kitazawa (Osaka) 1,2,3(11-18 -- 12-06) | ooo-- | "Dynamics of Non-Gaussianity in Heavy Ion Collisions" [PD/Col.] We investigate time evolution of higher-order cumulants of bulk fluctuations of conserved charges in the hadronic stage in heavy ion collisions. The dynamical evolution of the non-Gaussian fluctuations are modeled by the diffusion master equation. In this model, we predict that the fourth-order cumulant is suppressed compared with the recently observed second-order one at ALICE. Significance of various cumulants as functions of rapidity acceptance as experimental observables to probe dynamical history of fireballs and global structure of QCD phase diagram are emphasized. |
Che-Ming Ko (Texas A&M) 3(12-02 -- 12-06) | --o-- | "Elliptic flow as a probe of the properties of baryon-rich QGP" [Col.] Using a partonic transport model based on the 3-flavor Nambu-Jona-Lasinio model and a relativistic hadronic transport model to describe, respectively, the evolution of the initial partonic and the final hadronic phase of heavy-ion collisions at energies carried out in the Beam-Energy Scan program of the Relativistic Heavy Ion Collider, we have studied the effects of both the partonic and hadronic mean-field potentials on the elliptic flow of particles relative to that of their antiparticles. We have found that to reproduce the measured relative elliptic flow differences between nucleons and antinucleons as well as between kaons and antikaons requires a vector coupling constant as large as 0.5 to 1.1 times the scalar coupling constant in the Nambu-Jona-Lasinio model. Implications of our results in understanding the QCD phase structure at finite baryon chemical potential will be discussed. |
Toru Kojo (Illinois) 2,3(11-25 -- 12-06) | -oo-- | "The Quark Mass Gap in Strong Magnetic Fields" [PD] It has been known that magnetic fields enhance the chiral symmetry breaking (ChSB). According to studies of QED or models of the 4-fermi interactions, it was expected that the enhanced ChSB would resist the chiral restoration effects, increasing critical temperatures for the chiral restoration and deconfinement. Recent lattice calculations, however, showed the opposite behavior: the critical temperatures are reduced as a magnetic field increases. I will discuss how to resolve this apparent paradox, emphasizing which characteristic features of QCD make differences from other models. |
Kei-Ichi Kondo (Chiba) 3(12-03 -- 12-05) | --o-- | |
Teiji Kunihiro (Kyoto) 1,2,3,4,5(11-18 -- 12-20) | ooooo | "Anomalous quark spectrum around QCD critical points" [PD] We study the quark spectrum at finite temperature near and above the pseudo-critical temperature and around the critical point of the chiral phase transition, taking into account of the possible para-pionic modes existing in the restored phase. Below the pion zero-binding temperature where the pionic modes are bound, the quark self-energy has van Hove singularity induced by the scattering of quarks with the bound pions. This singularity is found to cause a drastic change in the quark spectrum from that in the mean field approximation: The quark spectrum has an unexpected sharp peak at an energy considerably lower than the constituent quark mass, while the spectrum approaches the mean field one at high temperatures. We clarify that the emergence of these structures originates from the composite nature of the pionic modes which can have a dispersion relation of non-hyperbolic form in the medium at finite temperature. |
Robert Lang (München) 3(12-02 – 12-06) | --o-- | "Shear viscosity in a large-Nc NJL model from Kubo formalism" [] We apply a large-Nc expansion to the Kubo formalism to study the shear viscosity within the non-perturbative NJL model. We use different prototype parameterizations of the spectral width and discuss to what extent the NJL model can be treated perturbatively. We find strong effects on the momentum cutoff and point out that thermal constituent quark masses are crucial to avoid unphysical values for the ratio shear viscosity per entropy density |
Tuomas Lappi (Jyvaskyla) 3,4(12-02 -- 12-13) | --oo- | "Numerical studies of JIMWLK (and glasma) evolution" [IC/pre] |
Jinfeng Liao (Indiana / RIKEN BNL) 3,4(12-02 -- 12-10) | --oo- | "Strongly Interacting Matter In and Out of Equilibrium" [IC/pre] |
Shu Lin (RIKEN BNL) 1(11-18 -- 11-22) | o---- | "Thermodynamics and Z(N) interfaces in large N matrix model" [PD] The deconfinement phase transition of SU(N) gauge theory is of first order. Large N limit leads to peculiar features of the transition: In a matrix model, it has been shown that the transition appears second order due to the emergence of critical exponents, which is analogous to Gross-Witten-Wadia transition. In the deconfined phase, the center Z(N) symmetry is broken, which allows for N degenerate vacua. In a recent work, we considered a topological object interface that interpolates these vacua and computed associated interface tensions near the phase transition. We found vanishing result for interface tension at the transition temperature and the results also indicate a noncommutativity between large N limit and deconfinement limit. We further considered 1/N correction to the thermodynamics in the model and observed nontrivial dependence on N. |
Kazuya Mameda (Keio) 1,2(11-18 -- 11-29) | oo--- | "QCD theta-vacua from Chiral Limit to Quenched Limit" |
Tetsuo Matsui (Tokyo) 2,4(11-27 – 12-09) | -o-o- | "Entropy in Quark-Hadron Transition" [Col.] Entropy is sensitive to the effective degrees of freedom thermally excited in the system. I discuss how it changes through the quark-hadron phase transition, or cross over transition, as described by an effective theory of QCD, called the PNJL model. This talk is based on the work in collaboration with Gordon Baym and Kanako Yamazaki. |
Larry McLerran (BNL) 2,3,4(11-25 -- 12-10) | -ooo- | "CGC, Glasma, RHIC and LHC" [IC/pre] |
Rene Meyer (RIKEN) 3(12-02 – 12-06) | --o-- | |
Yuki Minami (RIKEN) 3(12-02 -- 12-06) | --o-- | "Relativistic hydrodynamics from the projection operator method" [Col.] We study relativistic hydrodynamics in the linear regime, based on Mori's projection operator method. In relativistic hydrodynamics, it is considered that ambiguity about the fluid velocity occurs from a choice of a local rest frame: the Landau and Eckart frames. We find that the difference of the frames is not the choice of the local rest frame, but rather that of dynamic variables in the linear regime. We derive hydrodynamic equations in the both frames by the projection operator method. We show that natural derivation gives the linearized Landau equation. Also, we find that, even for the Eckart frame, the slow dynamics is actually described by the dynamic variables for the Landau frame. |
Kohtaroh Miura (KMI, Nagoya) 1(11-18 -- 11-22) | o---- | "Neutrino Spectral Property at Electroweak Scale Temperature" [PD] We investigate spectral properties and possible collective nature of the standard-model (SM) neutrinos at electroweak scale temperature (T) in the R_xi gauge. We show that the spectral density of the neutrino have a three-peak structure in the low-momentum region because of the Landau damping when T becomes comparable to the weak boson masses in the plasma. The three peaks are identified with a novel ultrasoft mode, the usual quasiparticle, and antiplasmino modes. Varying the gauge-fixing parameter xi, These collective modes appears independently of the gauge fixing and thus has a physical significance. We discuss possible implications of the neutrino spectral density to the particle cosmology in the context of the resonant leptogenesis. |
Bedangadas Mohanty (Bhubaneswar) 3(12-02 -- 12-07) | --o-- | "Study of QCD Phase Structure through High Energy Heavy Ion Collisions" [PD(Exp.)] |
Akihiko Monnai (RIKEN BNL) 3,4,5(12-02 -- 12-20) | --ooo | "Pre-equilibrium dynamics of QCD matter by gluon splitting" [IC/pre] Thermalization of quark-gluon matter in early stages of high-energy heavy ion collisions has been an issue of great interest and controversy since color glass condensate and glasma pictures tend to yield a far-from-equilibrium medium while the large momentum anisotropy observed in collider experiments supports nearly complete local thermalization. We present theoretically and numerically a novel model based on the parton splitting picture to give an efficient phenomenological description of the quick thermalization processes in a pre-equilibrated QCD medium. |
Pablo A. Morales (Keio) 1,2,3(11-18 -- 12-06) | ooo-- | "Topological current effect on hQCD at finite density and magnetic field" [PD] In this talk I will discuss the impact of the axial-vector interaction on the holographic QCD phase diagram emphasizing on newly found spatial modulation of quark matter. A magnetic field coupled with baryon density leads to a topological axial current so that the effect of the axial-vector interaction is crucially enhanced. Using the Sakai-Sugimoto model, we have found, contrary to a naive expectation, that the presence of a topological current results in the spatially modulated phase being less favored for a stronger magnetic field. Interpretation of the results will be attempted by explicit construction of the chiral condensate in the holographic set-up. Reference: 10.1103/PhysRevLett.111.051601 |
Kenji Morita (FIAS) 2,3,4,5(11-25 -- 12-20) | -oooo | "Probability Distribution of Net Baryon Number near the Phase Boundary" [Col.] We discuss property of the net baryon number fluctuations from a viewpoint of underlying probability distribution. We demonstrate structural change of the probability distribution in the vicinity of the chiral phase transition dependent on the nature of the critical property of the system. Then we show that the remnant of the change can be seen by taking the ratio of the probability distribution to a property constructed reference distribution. |
Berndt Mueller (BNL) 3,4(12-02 -- 12-13) | --oo- | "The Physics of QCD Matter" [Overview] |
Swagato Mukherjee (BNL) 2,3(11-25 -- 12-06) | -oo-- | "Strageness, Charm and Charmonia at High Temperatures" [PD] |
Marlene Nahrgang (Duke) 1(11-18 -- 11-22) | o---- | "Fluctuations at the QCD phase transition from dynamical models" [PD] |
Yasushi Nara (AIU) 4,5(12-11 -- 12-20) | ---oo | |
Jenifer Nebreda (YITP) 1,2,3,4,5(11-18 -- 12-20) | ooooo | "Regge trajectories of mesons from a dispersive connection to pole parameters" [(hadron)] Our results on obtaining the Regge trajectory of a resonance from its pole in a scattering process and from analytic constraints in the complex angular momentum plane will be presented. The method, suited for resonances that dominate an elastic scattering amplitude, has been applied to the rho(770) and the f0(500) resonances. Whereas for the former we obtain a linear Regge trajectory, characteristic of ordinary quark-antiquark states, for the latter we find a non-linear trajectory with a much smaller slope at the resonance mass. We also show that if a linear trajectory with a slope of typical size is imposed for the f0(500), the corresponding amplitude is at odds with the data. This provides a strong indication of the non-ordinary nature of the sigma meson. |
Chiho Nonaka (KMI, Nagoya) 1,2,3(,4,5)(11-18 -- 12-07) | ooooo | "Viscous Hydrodynamics for Relativistic Heavy-Ion Collisions" [Col.] At present, a hydrodynamic model is considered as one of promising phenomenological models for understanding relativistic heavy ion collisions. A numerical scheme which is adopted for solving the relativistic hydrodynamical equation is an important ingredient in hydrodynamical models, but only a little attention has been paid to this point. In particular, when we start to investigate viscosity effects and event-by-event fluctuations, we need to choose suitable numerical schemes carefully. Here, we present a state-of-the-art algorithm for solving the relativistic viscous hydrodynamic equation with QCD equation of state. The numerical method is based on the second-order Godunov method and has less numerical dissipation, which are important in describing of quark-gluon plasma in high energy heavy-ion collisions. We employ our new numerical scheme to investigation of higher harmonics which contains detail information of the quark-gluon plasma (QGP) property. |
Jorge Noronha (Sao Paulo) 2,3,4(11-29 – 12-15) | -ooo- | "New Results for the Transport Coefficients of the QGP from Holography" [Hard] |
Akira Ohnishi (YITP) 1,2,3,4,5(11-18 -- 12-20) | ooooo | "Phase diagram and a sign problem in lattice QCD at the strong coupling" [PD] It is a challenging problem to obtain nuclear matter properties at various temperature and density from the fundamental theory of the strong interaction, quantum chromodynamics (QCD). The QCD coupling constant is still large in the nuclear scale, and we need non-perturbative approaches. The Monte-Carlo simulations of lattice QCD, ab initio non-perturbative method to solve QCD, are successful at zero baryon density but have the sign problem at finite density. We discuss the phase diagram of QCD (phases at finite T and mu) using the strong coupling lattice QCD (SC-LQCD). The strong coupling lattice QCD is one of the promising approaches to overcome the sign problem. We start from the strong coupling limit, where the QCD coupling is infinite, 1/g^2=0. For a given order of inverse coupling, we obtain an effective action of quarks and loops by integrating out link variables. Since we can perform link integral semi-analytically, the cancellation of the statistical weight is suppressed. Especially, it seems that the sign problem has been solved in the strong coupling limit; two different approaches [1,2] gave the same phase boundary of the chiral transition, and the volume dependence is found to be small. In the presentation, I first give a brief overview of recent progress in lattice QCD at finite density. Next I introduce the ideas and show recent results in SC-LQCD. In the final part of the presentation, I discuss the sign problem in SC-LQCD; while the statistical weight cancellation is mild, we still have a sign problem in SC-LQCD as in other quantum Monte-Carlo calculation of many-body problem. Severity and possible ways to overcome this sign problem is discussed. [1] P. de Forcrand and M. Fromm, Phys. Rev. Lett. 104, 112005 (2010); W. Unger and P. de Forcrand, J. Phys. G 38, 124190 (2011). [2] A. Ohnishi, T. Ichihara, T. Z. Nakano, PoS LATTICE2012 (2012), 088 [arXiv:1211.2282]. |
Keisuke Ohtani (TITech) 3(12-02 -- 12-06) | --o-- | "Nucleon spectral function in nuclear matter from QCD sum rules" [PD] The QCD sum rule method is a powerful tool for studying hadron properties directly from QCD. In this method, the correlation function of an interpolating field operator coupled to the hadron of interest, which can be calculated in the deep Euclidean region by the operator product expansion (OPE), is related to the hadronic spectral function. The non-perturbative contributions in the correlation function are expressed by vacuum condensates such as the chiral condensate. In the traditional analysis, it is necessary to assume some specific functional form, such as the ``pole + continuum"-ansatz, for the spectral function. On the other hand, our approach with the help of the Maximum Entropy Method (MEM) is able to extract the spectral function without assuming a specific form. The method has been successfully applied to the rho meson sum rule [1] and the nucleon sum rule [2] in vacuum. We have applied this analysis method of QCD sum rules to the spectral function of the nucleon and its negative parity excited states in vacuum [3]. We construct the parity projected nucleon sum rules including the first order alpha_s corrections by using a phase-rotated Gaussian kernel. Both the positive and negative parity spectral function of the nucleon are extracted after the MEM is applied to the sum rule. We find that the difference between the positive and negative parity spectral function is mainly caused by the chiral condensate. Applying this method to the analyses in nuclear matter, the mass modification of both the positive and negative parity states can be examined. An investigation of the nucleon spectral function in nuclear matter is now in progress. [1] P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010). [2] K. Ohtani, P. Gubler and M. Oka, Eur. Phys. J. A 47, 114 (2011). [3] K. Ohtani, P. Gubler and M. Oka, Phys. Rev. D 87, 034027 (2013). |
Jean-Yves Ollitrault (Saclay) 2,3(11-24 -- 12-07) | -oo-- | "Constraining models of initial conditions with flow data" [Col.] We carry out a combined analysis of elliptic and triangular flow data using viscous relativistic hydrodynamics. We show that these data allow to put tight constraints on models of the early dynamics of a nucleus-nucleus collision. Specifically, the rms values of the initial ellipticity and the initial triangularity are constrained to lie within a narrow band for each centrality. We use these constraints as a filter for existing Monte-Carlo models of initial state. |
Sho Ozaki (Yonsei) 2,3,4(11-25 -- 12-13) | -ooo- | "QCD effective potential with strong magnetic field" [PD] In this talk, I will discuss the QCD vacuum in the presence of magnetic fields in terms of the QCD effective potential. Since the gluon does not interact with the magnetic field (photon), the vacuum is intact under the magnetic field within the pure Yang-Mills theory. Through the quark contributions, however, the vacuum can be affected by the magnetic field in the QCD. By using the Schwinger’s proper time method, we analytically drive the one-loop QCD effective potential with the magnetic field. We obtain the correct one-loop beta functions of both QCD and QED, and the resulting effective potential is renormalization group invariant. In our results, the chromo-magnetic field in the QCD vacuum prefers to be parallel to the external magnetic field, which is consistent with the recent lattice QCD results. Furthermore, the chromo-magnetic field condensate is enhanced by the external magnetic field through the quark contributions. This result supports the gluonic catalysis induced by the magnetic field, which is recently observed in lattice QCD simulations. |
LongGang Pang (CCNU) 1,2,3(11-18 -- 12-06) | ooo-- | "Longitudinal Fluctuation And Di-hadron Correlation In Event-by-event 3+1D Hydrodynamics" [Col.] Two dimensional azimuthal di-hadron correlation are studied in event-by-event (3+1D) hydrodynamic simulation with fluctuating initial conditions from HIJING Monte Carlo model and parton cascade in AMPT. The intrinsic correlation from mini-jets and string melting are introduced in the beginning, and the relics of the initrinsic correlation together with the strong collective flow in event-by-event hydro will give a good description to experimental data. We quantitively compared the per-trigger particle yield from our hydro simulation with CMS and PHENIX experimental data by subtracting the long range part from the short range correlation. |
Jan M. Pawlowski (Heidelberg) 2,3(11-26 -- 12-05) | -oo-- | "Exploring the phase structure and dynamics of QCD" [PD] I give an update on the phase structure of QCD at vanishing and finite temperature and density. Specifically results are discussed for the order parameters of confinement-deconfinement and chiral phase transitions, the nature of these transitions and their interrelation, as well as the thermodynamics of QCD. The above results are then used for the computation of gluon spectral functions and transport coefficients, i.e. the viscosity over entropy ratio at finite temperature. I will also discuss the occurance of condensation phenomena and turbulent phases in the far-from-equilibrium dynamics of gauge theories at the example of an Abelian Higgs model. This model is specifically interesting as it bears a close resembles to the gauge sector of QCD within specific gauges. Moreover, the strength of the gauge coupling relative to the scalar self-interaction is a free parameter which allows the detailed study of the effects of the gauge field dynamics. |
Salvatore Plumari (Catania) 2(11-23 – 11-30) | -o--- | "Anisotropic flows and the shear viscosity of the QGP within a kinetic approach" [Col.] We discuss the build up of anisotropic flows v_n in a transport approach at fixed shear viscosity to enetropy density ratio. We show, exploring the T dependence of eta/s, that a study of v_n in a wide p_T range allows to understand the difference behind the collective flows at LHC respect to RHIC. In particular we study the effect of a temperature dependent eta/s at different beam energies from RHIC for Au+Au at sqrt{s}= 62.4, 200 GeV to LHC energies for Pb+Pb at sqrt{s}= 2.76 TeV. We find that for the different beam energies considered the suppression of the elliptic flow due to the viscosity of the medium has different contaminations coming from the hadronic or QGP phase depending on the average energy of the system. In particular we observe that at LHC the elliptic flow is less contaminated by the hadronic phase allowing a better study of the QGP properties. We show that it is possible to have a nearly invariant v_2(p_T) as observed experimetally only if eta/s has a fall and rise with the temperature with a behavior typical of a phase transition. |
Johann Rafelski (Arizona) 3(12-02 – 12-06) | --o-- | "Universality of Hadronization Condition"
A quark-gluon plasma hadronization into free-streaming hadrons means that irrespective of how QGP state was formed and how it evolves to hadronization, we should observe in the laboratory the same physical conditions of the fireball particle source. The properties of the QGP fireball are derived from what we see in all emitted hadronic particles. After seeing early evidence of universal hadronization comparing SPS and RHIC data (http://arxiv.org/abs/arXiv:0902.0063, J.Phys.G36:064017,2009) we have now established this convincingly comparing the RHIC-62 GeV and LHC-2760 GeV results for a wide range of geometric collision centrality considered in these experiments (http://arxiv.org/abs/arXiv:1303.0913, \doi{10.1103/PhysRevC.88.021901}). Our study relies on a precise method of hadron abundance analysis within the statistical hadronization model (SHM) implemented within the SHARE approach. We describe very well all available particle production yields. We find SHM parameters which are consistent as function of both collision energy and reaction volume, both in a range of a factor 40 looking at RHIC and LHC. The highly variable particle yields as function of centrality and reaction energy originate mainly in the strong variation in the volume parameter $dV/dy$, and strangeness phase space occupancy $\gamma_s$. |
Krzysztof Redlich (Wroclaw) 2,3(11-27 – 12-04) | -oo-- | "The Polyakov loop and charge fluctuations and QCD critical points" [PD] |
Thorsten Renk (Jyvaskyla) 3,4(12-01 -- 12-12) | --oo- | "Jet tomography at RHIC and LHC" [Hard]
The original promise when jet tomography was first suggested in the context of ultrarelativistic heavy-ion collisions was to use the interaction of hard partons with the QCD medium to measure the medium density. This turned out to be more complicated as anticipated since the parton-medium interaction itself is not known with sufficient precision. The wealth of high P_T data from RHIC and LHC however is creating a situation in which the two issues can be addressed simultaneously. I review how a systematic comparison of models with RHIC and LHC observables practically eliminates all model scenarios except a 'standard' energy loss model based on pQCD medium induced radiation and subleading elastic energy transfer, and how this model can be used together with state of the art event-by-event fluid dynamics to obtain first reliable tomographic measurements of the medium. |
Victor Roy (CCNU) 1,2,3(11-18 -- 12-06) | ooo-- | "Flow fluctuation and event plane correlation from E-by-E Hydrodynamics and Transport Model" [Col.]
The simulated result of event-by-event measured flow harmonics from a 3+1D hydrodynamics and transport model will be presented. Specifically we will discuss the correlation between flow harmonics vn to the corresponding initial asymmetry εn (n=2-5) for Au+Au and Pb+Pb collisions at RHIC and LHC energies respectively. We are using the same fluctuating initial condition for both the hydrodynamics and transport model, which is obtained from HIJING. The initial condition used in our study contains fluctuation in both transverse and longitudinal direction. This enables us to study the correlation in the longitudinal direction. We are using two different dynamical models (Hydrodynamics and Transport model) with the same initial condition, which will also allow us to investigate the effect of evolution dynamics on the final flow harmonics. The comparison of theoretical result to the experimental data on event-by-event distribution of flow harmonics measured at LHC for Pb+Pb collision at CM energy 2.76 TeV will also be presented. |
Marco Ruggieri (Catania) 4(12-07 -- 12-15) | ---o- | "Elliptic flow from thermal and KLN initial conditions" [IC/pre] We discuss the effect of a nonequilibrium initial condition, characterized by a saturation scale, on the building up of the elliptic flow produced in heavy ion collisions at RHIC and LHC, within an approach based on transport theory at fixed $eta/s$. |
Yohei Saito (KEK) 2,3(11-25 -- 12-06) | -oo-- | "Microscopic identification of dissipative modes in relativistic field theories" [Col.] We present an argument to support the existence of dissipative modes in relativistic field theories. In an O(N) phi^4 theory in spatial dimension d which is lowerer than or equal to 3, a relaxation constant Gamma of a two-point function in an infrared region is shown to be finite within the two-particle irreducible (2PI) framework at the next-leading order (NLO) of 1/N expansion. This immediately implies that a slow dissipative mode is microscopically identified in the two-point function. Contrary, NLO calculation in the one-particle irreducible (1PI) framework fails to yield a finite relaxation constant. Comparing the results in 1PI and 2PI frameworks, one concludes that dissipation emerges from multiple scattering of a particle with a heat bath, which is appropriately treated in the 2PI-NLO calculation through the resummation of secular terms to improve long-time behavior of the two-point function. Assuming that this slow dissipative mode survives at the critical point, one can identify the dynamic critical exponent z for the two-point function as z=2-eta. We also discuss possible improvement of the result. |
Yuji Sakai (RIKEN) 3(12-02 -- 12-06) | --o-- | |
Miki Sakaida (Osaka) 3(12-02 -- 12-08) | --o-- | "Effect of the global charge conservation on the time evolution of higher order cumulants in ultrarelativistic heavy ion collisions" [PD] Recent experimental results at ALICE show that the value of the second-order cumulant of the net-electric charge is suppressed compared with the value in the equilibrated hadronic medium and depends on the size of the rapidity window. These results suggest that fluctuations of conserved charges generated in the deconfined medium survive until the final state in ultrarelativistic heavy ion collisions. However, the suppression can also take place owing to the global charge conservation. We evaluate the effect of the global charge conservation on cumulants by studying the time evolution of cumulants of the conserved charges with diffusion master equation in finite volume systems with boundaries. Our result suggests that the effect of the global charge conservation is almost negligible in the experimental results with the current rapidity windows at ALICE. |
Chihiro Sasaki (FIAS) 2,3(11-25 -- 12-06) | -oo-- | "Fluctuations and the QCD Phase Structure from Effective Theories" [PD] "Chiral Thermodynamics with Charm" I plan to present one of the following issues: (1) Yang-Mills thermodynamics (2) thermodynamics of heavy-light hadrons |
Takahiro Sasaki (Kyushu) 3(12-02 -- 12-06) | --o-- | |
Daisuke Sato (Kanazawa) 3(12-02 -- 12-06) | --o-- | "Chiral phase transition of QCD low-energy model in a constant magnetic field" [PD] We analyze the linear sigma model coupled to quarks in a constant magnetic field B using the non-perturbative renormalization group. In this RG analysis, the coefficients of the kinetic terms of the meson fields are dynamically generated because the meson fields in our model are regarded as the composite states of a quark and an antiquark. Owing to the dimensional reduction via the compositeness of the neutral pion, we expect that the chiral-restoration temperature T_c decreases with B. This mechanism is supposed by Fukushima and Hidaka to explain the decreasing behavior of T_c indicated by recent lattice QCD simulations. However the decreasing behavior is not seen in our result without the cutoff of the transverse momentum of the neutral pion, which is introduced in their work. |
Daisuke Satow (RIKEN) 2,3,4(11-25 -- 12-13) | -ooo- | "(Quasi-) Nambu-Goldstone Fermion in Hot QCD Plasma and Bose-Fermi Cold Atom System" [PD] It was suggested that supersymmetry (SUSY) is broken at finite temperature, and as a result of the symmetry breaking, a Nambu-Goldstone fermion (goldstino) related to SUSY breaking appears. Since dispersion relations of quarks and gluons are almost degenerate at extremely high temperature, quasi-zero energy quark excitation was suggested to exist though QCD does not have exact SUSY. As for the condensed matter system, a setup of cold atom system in which the Hamiltonian has SUSY was proposed, the goldstino was suggested to exist, and the dispersion relation of that mode at zero temperature was obtained recently. In this presentation, we obtain the expressions for the dispersion relation of the goldstino in cold atom system at finite temperature, and compare it with the dispersion of the quasi zero-mode in QCD. Furthermore, we show that the form of the dispersion relation of the goldstino can be understood by using an analogy with a magnon in ferromagnet. We also discuss on how the dispersion relation of the goldstino is reflected in observable quantities in experiment. |
Francesco Scardina (Catania) 4(12-07 -- 12-15) | ---o- | "Dynamical evolution of heavy quarks: Boltzmann vs Langevin" [IC/pre] The propagation of heavy flavour through the quark gluon plasma has been treated commonly within the framework of Langevin dynamics, i.e. assuming the heavy flavour momentum transfer is much smaller than that of light flavor. We present a thorough study of the thermalization dynamics, average momentum evolution and of the approximations involved by Langevin equation by mean of a direct comparison with the full collisional integral within the framework of Boltzmann transport equation. We have carried out simulations using the two different approaches considering the dynamical evolution of a system consisting of gluons and heavy quarks within a fixed box. Moreover we have performed simulations for realistic heavy Ion collisions at both RHIC and LHC energies and we have evaluated the nuclear suppression factor,R_AA, and the elliptic flow, v_2, of the charm and bottom within the Langevin and Boltzmann approach. We have compared the results obtained in both approaches which can differ substantially leading to quite different values extracted for the the heavy quark diffusion coefficient. |
Jurgen Schukraft (CERN) 3(12-02 -- 12-06) | --o-- | "Heavy Ion Physics at the LHC: What's new ? What's next ?" |
Akihiro Shibata (KEK) 3(12-03 -- 12-06) | --o-- | |
Kenta Shigaki (Hiroshima) 3(12-02 -- 12-06) | --o-- | |
Huichao Song (Peking) 2,3(11-24 -- 12-07) | -oo-- | "Dynamical Modeling and Soft Physics at RHIC and the LHC" [Col.] In this talk, I will review the recent progress on viscous hydrodynamics and hybrid model for extracting the quark-gluon plasma (QGP) specific shear viscosity at top RHIC and LHC energies. Then I will briefly address Beam Energy Scan (BEC) program at RHIC, introduce a dynamical model near the critical point and discuss some theoretical results obtained recently. |
Alexander Savelievich Sorin (Dubna) 2,3(11-23 -- 12-07) | -oo-- | "Vorticity and asymmetries at NICA" [Col.(Exp.)] Experimental manifestations of P-odd effects related to the vorticity and hydrodynamic helicity in non-central heavy ion collisions are discused, which is based on their simulations in the NICA kinematics in framework of the kinetic Quark-Gluon String Model. For the NICA heavy ion collisions characterised by a large baryonic charge of the forming medium the effect should manifest in neutron asymmetries. The polarization of hyperons and P-odd correlations of particle momenta probing the vorticity are discussed. |
Michael Strickland (Kent State U.) 1,2(11-18 -- 11-28) | oo--- | "Resummed QCD thermodynamics at finite temperature and chemical potential" [Col.] "Second-Order Anisotropic Hydrodynamics" |
Kei Suzuki (TITech) 3(12-02 -- 12-06) | --o-- | "Medium modification of mesons with heavy quarks from QCD sum rules" [Hard] It is interesting to investigate behaviors of the hadrons including heavy quark (charm or bottom quark) at finite temperature and density. The heavy ion collision experiments at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) have revealed that the quarkonium productions are suppressed in the thermal QCD medium. Recent experimental measurements at the LHC have suggested significant modification of the bottomonium spectra in hot matter from the comparison between the p-p and Pb-Pb collisions. The data indicate larger suppression of the excited states than the ground state. Also, in the future, experiments by the Facility for Antiproton and Ion Research (FAIR) at GSI are expected to study properties of compressed baryonic matter where the open charmed (D) meson is modified. Our purpose of this work is to study these phenomena from a theoretical viewpoint. In this work, we investigate behaviors of heavy quark meson spectral functions at finite temperature and density from QCD sum rules with the maximum entropy method (MEM). Our approach [1] enables us to extract directly the shapes of the spectral functions without phenomenological assumptions. Therefore, this is a suitable tool to study the deformation of the spectral functions upon the change of the temperature and density. In this talk, based on [2,3], we will discuss the quarkonium (charmonium and bottomonium) spectra at finite temperature by using the same method. As a result, we obtained melting temperatures of the ground states of the charmonia and bottomonia. Furthermore, we find evidence for the melting of the excited states of the bottomonium vector channel, Upsilon(2S) and Upsilon(3S), in the temperature region of 1.5 - 2.0 Tc, which could provide a possible interpretation for the above-mentioned experimental findings recently observed at the LHC. Also, we will show the D meson spectra in the nuclear medium. [1] P. Gubler and M. Oka, Prog. Theor. Phys. 124, 995 (2010) [2] P. Gubler, K. Morita and M. Oka, Phys. Rev. Lett. 107, 092003 (2011) [3] K. Suzuki, P. Gubler, K. Morita and M. Oka, Nucl. Phys. A897, 28 (2013) |
Naoto Tanji (KEK) 3,4,5(12-02 -- 12-20) | --ooo | "Quark production in glasma" [IC/pre] We investigate the quark production from classical gauge fields given by color glass initial conditions. Computing the number of quark pairs produced from purely gluonic initial states is of great significance to understand the chemical equilibration of quark-gluon plasma. This problem has been studied by Gelis, Kajantie and Lappi. In the earlier study, however, the boost invariance of the system was not appropriately treated, and there were limitations from numerical costs. We give a formulation which keeps the boost invariance manifestly, and employ a Monte Carlo technique which reduces the numerical costs significantly. |
Hidetoshi Taya (Tokyo) 3,4(12-02 -- 12-13) | --oo- | |
Giorgio Torrieri (Frankfurt) 3(11-30 -- 12-07) | --o-- | "Theory and phenomenology of quarkyonic matter" [PD] I will argue for the presence of a percolation-type phase transition at moderate temperature and density QCD, and show this transition is curved in T,rhoB and number of colors. Percolating matter is, in many ways, analogous to the recently proposed "Quarkyonic Phase". I will then discuss how to look for this phase in electromagnetic signatures of Quark Gluon Plasma. Based on http://inspirehep.net/record/893765?ln=en http://inspirehep.net/record/1111030?ln=en http://inspirehep.net/record/1217728?ln=en |
Shoichiro Tsutsui (Kyoto) 1,2,3,4,5(11-18 -- 12-20) | ooooo | "Particle production based on 2PI formalism" [IC/pre] Particle production in quantum dynamics under the time dependent classical background fields plays important roles in the thermalization process of relativistic heavy-ion collisions. We apply two particle irreducible(2PI) formalism to the early and later stages of the thermalization process and discuss some properties of glasma instabilities. For this purpose, we perturbatively solve equations of motion of classical background gluon fields and Kadanoff-Baym-CJT equation simultaneously up to 1-loop level. We have two sequential instabilities which directly leads to explosive particle production on the basis of 2PI formalism. Furthermore, our results imply that the initial longitudinal fluctuation of classical gluon fields generate the secondary instabilities. |
Raju Venugopalan (BNL) 3,4(12-04 -- 12-11) | --oo- | "The non-equilibrium dynamics of strongly correlated glue" [IC/pre] |
Xin-Nian Wang (CCNU / LBNL) 3(12-01 -- 12-07) | --o-- | "Jet transport coefficients in heavy-ion collisions" [Hard] Jet quenching in heavy-ion collisions is determined mostly by jet transport coefficients which provide important information about properties of the dense matter. I will discuss theoretical estimates of the jet transport coefficients, their dependence on medium properties and how current experimental data on jet quenching provide constraints on their values. |
Kazuhiro Watanabe (Tokyo) 5(12-16 -- 12-20) | ----o | |
Anton Wiranata (CCNU / LBNL) 2,3(11-25 -- 12-06) | -oo-- | "Can hot interacting hadrons become a ”perfect” fluid?" [Col.] Shear viscosity $eta$ and entropy density $s$ of a hadronic resonance gas are calculated consistently using the Chapman-Enskog and virial expansion methods using the $K$-matrix parameterization of hadronic cross sections which preserves the unitarity of the $T$-matrix. In the $pi-K-N-eta$ mixture considered, a total of 55 resonances up to 2 GeV were included. Comparisons are also made to results with other hadronic cross sections such as the Breit-Wigner (BW) and, where available, experimental phase shift parameterizations. The BW parameterization fails to preserve unitarity of the $T-$matrix for nearby resonances, whereas experimental phase shifts are not available for all resonances considered. Hadronic interactions forming resonances are shown to decrease the shear viscosity and increase the entropy density leading to a substantial reduction of $eta/s$ as the QCD phase transition temperature is approached. |
Bowen Xiao (CCNU) 3,4,5(12-02 -- 12-20) | --ooo | "Probing Saturation Physics in pA Collisions" [Hard] In this talk, I will review recent progress in the saturation physics study , especially in the pA collisions . |
Jiechen Xu (Columbia) 2,3,4(11-27 -- 12-13) | -ooo- | "Azimuthal Jet Flavor Tomography via CUJET with Running Coupling in 2+1D Viscous QGP Fluids" [Hard] To quantitatively predict jet quenching observables at both RHIC and LHC, we built CUJET, a new perturbative quantum chromodynamics (pQCD) tomographic model. CUJET implements numerical calculation of dynamical Djordjevic-Gyulassy-Levai-Vitev (DGLV) opacity series, and convolutes both radiative and elastic energy loss. By introducing multi-scale running coupling, CUJET1.0 is able to explain the surprising transparency at LHC, while correctly fit RHIC's nuclear modification factor (RAA). CUJET2.0 bridges the gap between CUJET1.0 and 2+1D viscous hydro fields. Using VISH2+1 as the bulk evolution profile, we show that CUJET2.0's RAA results are consistent with both RHIC and LHC data, and imply a non-trivial absolute jet transport coefficient in the medium. We find a robust level crossing of light and heavy flavor's RAA with both static and expanding background, while the fit of single-particle azimuthal anisotropy (v2) remains to be explained at RHIC and LHC. |
Nu Xu (CCNU / LBNL) 3,4(12-01 -- 12-11) | --oo- | "Study QCD Phase Diagram in High-Energy Nuclear Collisions" [PD(Exp.)] We will discussion recent results from RHIC Beam Energy Scan program. The implications on the QCD phase diagram and QGP will be discussed. I will end the with near future physics programs at RHIC. |
Masatoshi Yamada (Kanazawa) 1,2,3(11-18 -- 12-06) | ooo-- | "Analysis of the chiral effective model of QCD using Non-perturbative Renormalization Group at finite temperature and finite density" [PD] We analyze chiral effective models of QCD by using Non-perturbative Renormalization Group(NPRG) at finite temperature and finite density. We discuss the chiral phase transition in the models. There are various non-perturbative approaches to QCD, such as the mean-field approximation or the Schwinger-Dyson equation. However, they have difficulties in the further improvement of the approximation. On the other hand, NPRG method gives us not only equivalent results to these methods in the lowest order approximation but also systematic method of improvement of approximation. We compare the improved results in NPRG method with the mean field approximation. |
Arata Yamamoto (RIKEN) 3(12-02 -- 12-06) | --o-- | |
Kanako Yamazaki (Tokyo) 1,2,3(11-18 -- 12-06) | ooo-- | "Quark-Hadron Phase Transition in the PNJL model for interacting quarks" [PD] We study the QCD phase transitions by a Nambu-Jona-Lasinio model extended with the Polyakov loop, incorporating the effect of the color confinement. The aim of this work is to describe the change of degrees of freedom from hadrons to quarks through the transition region. For this purpose, we take hadronic correlations into account, beyond the mean field approximation; hadrons are described as collective modes of quarks and anti-quarks. We show that the equation of state changes continuously from that of a hadron gas at low temperatures to that of the quark-gluon plasma at high temperatures. |
Koji Yonemura (Kyushu) 3(12-02 -- 12-06) | --o-- | |
Tetsuya Yoshida (TITech) 3(12-02 -- 12-06) | --o-- |