Critical Temperature of Chiral Symmetry Restoration for Quark Matter with a Chiral Chemical Potential

TL;DR

This study investigates how a chiral chemical potential affects the critical temperature and nature of chiral symmetry restoration in quark matter using a nonlocal NJL model, revealing that the critical temperature rises with increasing chiral chemical potential.

Contribution

It introduces a nonlocal NJL model with a momentum-dependent quark mass function to analyze chiral symmetry restoration at finite temperature and chemical potential.

Findings

Critical temperature increases with chiral chemical potential.

The phase transition remains second order across the studied range.

The model aligns with QCD asymptotic behavior.

Abstract

In this article we study restoration of chiral symmetry at finite temperature for quark matter with a chiral chemical potential, $\mu_5$, by means of a nonlocal Nambu-Jona-Lasinio model. This model allows to introduce in the simplest way possible a Euclidean momentum, $p_E$, dependent quark mass function which decays (neglecting logarithms) as $1/p_E^2$ for large $p_E$, in agreement with asymptotic behaviour expected in QCD in presence of a nonperturbative quark condensate. We focus on the critical temperature for chiral symmetry restoration in the chiral limit, $T_c$, versus $\mu_5$, as well as on the order of the phase transition. We find that $T_c$ increases with $\mu_5$, and that the transition remains of the second order for the whole range of $\mu_5$ considered.