Viscosity and thermodynamic properties of QGP in relativistic heavy ion collisions

TL;DR

This paper investigates the viscosity and thermodynamic properties of quark-gluon plasma (QGP) in heavy ion collisions, revealing that interactions significantly reduce shear viscosity and the viscosity to entropy ratio.

Contribution

It introduces a novel analysis of QGP properties using recent equilibrium distribution functions from advanced QCD equations of state.

Findings

Interactions decrease shear viscosity of QGP.

Interactions lower the viscosity to entropy density ratio.

Temperature dependence of thermodynamic quantities analyzed.

Abstract

We study the viscosity and thermodynamic properties of QGP at RHIC by employing the recently extracted equilibrium distribution functions from two hot QCD equations of state of $O(g^5)$ and $O(g^6\ln(1/g))$ respectively. After obtaining the temperature dependence of energy density, and entropy density, we focus our attention on the determination of shear viscosity for a rapidly expanding interacting plasma, as a function of temperature. We find that interactions significantly decrease the shear viscosity. They decrease the viscosity to entropy density ratio, $\eta/{\mathcal S}$ as well.