Phase diagram and critical properties within an effective model of QCD: the Nambu-Jona-Lasinio model coupled to the Polyakov loop

TL;DR

This paper explores the phase diagram of an effective QCD model, analyzing chiral and deconfinement transitions at finite temperature and chemical potential, and examines the impact of flavor-mixing interaction strength on the critical end point.

Contribution

It provides a detailed analysis of the phase diagram within the Polyakov--Nambu--Jona-Lasinio model, highlighting how flavor-mixing influences the critical end point's location.

Findings

Critical end point shifts to lower temperatures with weaker flavor-mixing.

The phase diagram aligns with thermodynamic expectations and lattice data.

Disappearance of the critical end point at very weak flavor-mixing.

Abstract

We investigate the phase diagram of the so-called Polyakov--Nambu--Jona-Lasinio model at finite temperature and non-zero chemical potential with three quark flavors. Chiral and deconfinement phase transitions are discussed and the relevant order-like parameters are analyzed. The results are compared with simple thermodynamic expectations and lattice data. We present the phase diagram in the ($T,\,\mu_B)$ plane, paying special attention to the critical end point: as the strength of the flavor-mixing interaction becomes weaker, the critical end point moves to low temperatures and can even disappear.