The QCD critical end point in the PNJL model

TL;DR

This paper explores how the Polyakov loop influences the chiral phase transition in the PNJL model, shifting critical points and aligning results more closely with lattice QCD, while analyzing critical behavior near the end point.

Contribution

It demonstrates that including the Polyakov loop in the PNJL model shifts the critical points to higher temperatures and reproduces universal critical exponents consistent with lattice results.

Findings

Polyakov loop shifts critical points to higher temperatures.

PNJL results align better with lattice QCD data.

Critical exponents match universal behavior.

Abstract

We investigate the role played by the Polyakov loop in the dynamics of the chiral phase transition in the framework of the so-called PNJL model in the SU(2)sector. We present the phase diagram where the inclusion of the Polyakov loop moves the critical points to higher temperatures, compared with the NJL model results. The critical properties of physical observables, such as the baryon number susceptibility and the specific heat, are analyzed in the vicinity of the critical end point, with special focus on their critical exponents. The results with the PNJL model are closer to lattice results and we also recover the universal behavior of the critical exponents of both the baryon susceptibility and the specific heat.