A quasi-particle model with a phenomenological critical point

TL;DR

This paper introduces a hybrid quasiparticle model with a phenomenological critical point, combining lattice QCD data and hadronic models to describe the QCD phase diagram with a crossover and first-order transition.

Contribution

It presents a novel hybrid parameterization of the QCD equation of state incorporating a phenomenological critical point and smooth crossover transition.

Findings

Model fits lattice QCD data for quark-gluon plasma

Describes hadronic phase with excluded volume resonance gas

Implements a phenomenological critical point and phase transition types

Abstract

A hybrid parameterization of a quasiparticle equation of state is proposed, with a critical point implemented phenomenologically. On the one hand, a quasiparticle model with finite chemical potential is employed for the quark-gluon plasma phase, calibrated to the lattice quantum chromodynamics data. On the other hand, the low-temperature region for the hadronic phase of the matter is described by the hadronic resonance gas model with excluded volume correction. A particular interpolation scheme is adopted so that the phase transition is a smooth crossover for small chemical potential. A phenomenological critical pointed is implemented beyond which the phase transition becomes that of the first order.