The Phase Structure of Dense QCD from Chiral Models

TL;DR

This paper explores the phase structure of dense QCD using chiral models, highlighting the Quarkyonic phase and the interplay between chiral symmetry and confinement, with implications for the QCD phase diagram.

Contribution

It introduces the Quarkyonic phase within chiral approaches and examines the N_c dependence of the phase diagram using the PNJL model.

Findings

Identification of a possible phase with broken chiral symmetry but unbroken center symmetry.

Strong enhancement of quark number susceptibility at center symmetry restoration.

Discussion of the N_c dependence of the QCD phase diagram.

Abstract

A new phase of dense QCD proposed in the limit of large number of colors, Quarkyonic Phase, is discussed in chiral approaches. The interplay between chiral symmetry breaking and confinement together with the $N_c$ dependence of the phase diagram are dealt with in the PNJL model. We also discuss a possible phase at finite density where chiral symmetry is spontaneously broken while its center remains unbroken. The quark number susceptibility exhibits a strong enhancement at the restoration point of the center symmetry rather than that of the chiral symmetry. This is reminiscent of the quarkyonic transition.