Critical behaviors near the (tri-)critical end point of QCD within the NJL model

TL;DR

This study explores the critical phenomena near the critical end point and tricritical point of QCD using the NJL model, focusing on phase transitions, susceptibilities, and critical exponents at finite density and temperature.

Contribution

It provides a detailed analysis of the critical behaviors and susceptibilities near the CEP and TCP within the NJL model, highlighting differences between physical and chiral limits.

Findings

Susceptibilities share the same critical behavior for physical quark mass.

Different features observed in susceptibilities in the chiral limit.

Phase diagram includes multi-solution regions for Nambu and Wigner phases.

Abstract

We investigate the dynamical chiral symmetry breaking and its restoration at finite density and temperature within the two-flavor Nambu-Jona-Lasinio model, and mainly focus on the critical behaviors near the critical end point (CEP) and tricritical point (TCP) of quantum chromodynamics. The multi-solution region of the Nambu and Wigner ones is determined in the phase diagram for the massive and massless current quark, respectively. We use the various susceptibilities to locate the CEP/TCP and then extract the critical exponents near them. Our calculations reveal that the various susceptibilities share the same critical behaviors for the physical current quark mass, while they show different features in the chiral limit.