Chiral crossover characterized by Mott transition at finite temperature

TL;DR

This paper proposes defining the chiral crossover temperature via the Mott transition of pseudo-Goldstone bosons, ensuring consistency with Goldstone's theorem, and demonstrates this approach analytically and numerically within a NJL model, including effects of magnetic fields.

Contribution

It introduces a new definition of the chiral crossover based on the Mott transition, aligning with Goldstone's theorem, and explores magnetic field effects on this transition.

Findings

Mott transition temperature correlates with chiral crossover.

Inverse magnetic catalysis observed in Mott transition temperature.

Analytical and numerical validation within NJL model.

Abstract

We discuss the proper definition for the chiral crossover at finite temperature, based on the Goldstone's theorem. Different from the usually used maximum change of chiral condensate, we propose to define the crossover temperature by the Mott transition of pseudo-Goldstone bosons, which, by definition, guarantees the Goldstone's theorem. We analytically and numerically demonstrate this property in frame of a Pauli-Villars regularized NJL model. In external magnetic field, we find that the Mott transition temperature shows an inverse magnetic catalysis effect.