Quasi-particle model of QGP - a revisit

TL;DR

This paper presents a thermodynamically consistent quasi-particle model of QGP that fits lattice data well using only one system-dependent parameter, without requiring additional effects like confinement or temperature-dependent bag constants.

Contribution

The study introduces a revised quasi-particle model of QGP that simplifies assumptions and achieves excellent agreement with lattice results using a single parameter.

Findings

Accurately fits lattice data for gluon and 2/3-flavor QGP

Provides thermodynamic functions from energy density calculations

Extends to finite chemical potential with good agreement

Abstract

The quasi-particle model of quark gluon plasma (QGP) is revisited here with thermodynamically consistent formalism, different from earlier studies, without the need of temperature dependent bag constant as well as other effects such as confinement effects, effective degrees of freedom etc. Our model has only one system dependent parameter and surpraisingly good fit to lattice results for gluon plasma, 2-flavor and 3-flavor QGP are obtained. The basic idea is to evaluate energy density $\epsilon$ first from grand partition function of quasi-particle QGP and then derive all other thermodynamic functions from $\epsilon$. Quasi-particles are assumed to have temperature dependent mass equal to plasma frequency. Energy density, pressure and speed of sound are evaluated and compared with available lattice data. We further extend the model to finite chemical potential, without any new parameters, to obtain quark density, quark susceptibility etc. and fits very well with the lattice results on 2-flavor QGP.