Crystalline Ground States in Polyakov-loop extended Nambu--Jona-Lasinio Models

TL;DR

This paper investigates the stability of crystalline (inhomogeneous) ground states in Polyakov-loop extended Nambu--Jona-Lasinio models, revealing their robustness across different parametrizations and highlighting the dependence of quarkyonic phases on model parameters.

Contribution

It demonstrates the stability of crystalline phases in the model against parametrization changes and explores the conditions for quarkyonic phases in the phase diagram.

Findings

Crystalline phases are stable across different Polyakov loop parametrizations.

The existence of a quarkyonic phase depends on the chosen parametrization.

Inhomogeneous chiral condensation is favored in certain regions of the phase diagram.

Abstract

Nambu--Jona-Lasinio-type models have been used extensively to study the dynamics of the theory of the strong interaction at finite temperature and quark chemical potential on a phenomenological level. In addition to these studies, which are often performed under the assumption that the ground state of the theory is homogeneous, searches for the existence of crystalline phases associated with inhomogeneous ground states have attracted a lot of interest in recent years. In this work, we study the Polyakov-loop extended Nambu--Jona-Lasinio model and find that the existence of a crystalline phase is stable against a variation of the parametrization of the underlying Polyakov loop potential. To this end, we adopt two prominent parametrizations. Moreover, we observe that the existence of a quarkyonic phase depends crucially on the parametrization, in particular in the regime of the phase diagram where inhomogeneous chiral condensation is favored.