Nuclear Theory·nucl-th

Wednesday·October 12, 2016

9 papers—3 primary·6 cross-listed

01
Dissociation of heavy quarkonium in hot QCD medium in a quasi-particle model
Vineet K. Agotiya🇮🇳 · Vinod Chandra🇮🇳 · M. Yousuf Jamal🇮🇳 · Indrani Nilima🇮🇳
Following a recent work on the effective description of the equations of state for hot QCD obtained from a Hard thermal loop expression for the gluon self-energy, in terms of the quasi-gluons and quasi- quark/anti-quarks with respective effective fugacities, the dissociation process of heavy quarkonium in hot QCD medium has been investigated. This has been done by investigating the medium modification to a heavy quark potential. The medium modified potential has a quite different form (a long range Coulomb tail in addition to the usual Yukawa term) in contrast to the usual picture of Debye screening. The flavor dependence of the binding energies of the heavy quarkonia states and the dissociation temperature have been obtained by employing the debye mass for pure gluonic and full QCD case computed employing the quasi-particle picture. Thus estimated dissociation patterns of the charmonium and bottomonium states, considering Debye mass from different approaches in pure gluonic case and full QCD, have shown good agreement with the other potential model studies.
nucl-thPRD(2016)·57 citations
02
Collision energy dependence of elliptic flow splitting between particles and their antiparticles from an extended multiphase transport model
Jun Xu🇨🇳 · Che Ming Ko🇺🇸
Based on an extended multiphase transport model, which includes mean-field potentials in both the partonic and hadronic phases, uses the mix-event coalescence, and respects charge conservation during the hadronic evolution, we have studied the collision energy dependence of the elliptic flow splitting between particles and their antiparticles. This extended transport model reproduces reasonably well the experimental data at lower collision energies but only describes qualitatively the elliptic flow splitting at higher beam energies. The present study thus indicates the existence of other mechanisms for the elliptic flow splitting besides the mean-field potentials and the need of further improvements of the multiphase transport model.
nucl-thhep-exnucl-exPRC(2016)·20 citations
03
Separate chemical freeze-outs of strange and non-strange hadrons and problem of residual chemical non-equilibrium of strangeness in relativistic heavy ion collisions
K.A. Bugaev🇺🇦 · D.R. Oliinychenko🇺🇦 · V.V. Sagun🇺🇦 · A.I. Ivanytskyi🇺🇦 · J. Cleymans🇿🇦 · E.S. Mironchuk🇷🇺 · E.G. Nikonov🇷🇺 · A.V. Taranenko🇷🇺 · G.M. Zinovjev🇺🇦
We present an elaborate version of the hadron resonance gas model with the combined treatment of separate chemical freeze-outs for strange and non-strange hadrons and with an additional $γ_{s}$ factor which accounts for the remaining strange particle non-equilibration. Within suggested approach the parameters of two chemical freeze-outs are connected by the conservation laws of entropy, baryonic charge, third isospin projection and strangeness. The developed model enables us to perform a high-quality fit of the hadron multiplicity ratios measured at AGS, SPS and RHIC with $χ^{2} / d o f ≃ 0.93$ . A special attention is paid to a successful description of the Strangeness Horn. The well-known problem of selective suppression of $Λ ˉ$ and $Ξ ˉ$ hyperons is also discussed. The main result is that for all collision energies the $γ_{s}$ factor is about 1 within the error bars, except for the center of mass collision energy 7.6 GeV at which we find about 20\% enhancement of strangeness. Also we confirm an existence of strong jumps in pressure, temperature and effective number of degrees of freedom at the stage of strange particle chemical freeze-out, when the center of mass collision energy changes from 4.3 to 4.9 GeV. We argue that these irregularities may signal about the quark-hadron phase transition.
nucl-thUkr.J.Phys.(2016)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE

Dissociation of heavy quarkonium in hot QCD medium in a quasi-particle model

Collision energy dependence of elliptic flow splitting between particles and their antiparticles from an extended multiphase transport model

Separate chemical freeze-outs of strange and non-strange hadrons and problem of residual chemical non-equilibrium of strangeness in relativistic heavy ion collisions

Affiliations