The $T-\mu$ phase diagram of the NJL model in the presence of explicit symmetry-breaking interactions

TL;DR

This paper investigates the phase diagram of the NJL model with explicit symmetry-breaking interactions, revealing a first order transition in strange quark mass at moderate chemical potentials, which could imply stable strange quark matter formation.

Contribution

It introduces a generalized 3-flavor NJL model with complete explicit chiral symmetry breaking interactions, showing new phase transition behavior.

Findings

Strange quark mass undergoes a first order transition at μ ~ 400 MeV.

Stable strange quark matter may form at lower chemical potentials.

The behavior is explained by the model's extended interactions.

Abstract

It is shown that the strange quark mass undergoes a first order transition in a generalized 3 flavor Nambu--Jona-Lasinio (NJL) Lagrangian which includes a complete set of explicit chiral symmetry breaking interactions. This transition occurs in a moderate chemical potential region $\mu \sim 400$ MeV, in addition to the usual chiral transition associated with the light quark sector. This favors the formation of stable strange quark matter at chemical potentials which are considerably lower than the ones discussed in the literature. The reason for this behavior is discussed.