Pion condensation in the Gross-Neveu model with nonzero baryon and isospin chemical potentials

TL;DR

This paper explores the phase structure of the (1+1)-dimensional two-flavor Gross-Neveu model under nonzero isospin and baryon chemical potentials, revealing diverse phases with pion condensation and various quasiparticle excitations.

Contribution

It provides a detailed analysis of the phase diagram and quasiparticle spectrum of the model at finite chemical potentials and temperature, highlighting new phases with pion condensation.

Findings

Rich phase structure with pion condensation phases

Presence of gapless and gapped quasiparticles

Identification of various one-quark excitations

Abstract

The properties of the two-flavored Gross-Neveu model in the (1+1)-dimensional spacetime are investigated in the presence of the isospin $\mu_I$ as well as quark number $\mu$ chemical potentials both at zero and nonzero temperatures. The consideration is performed in the limit $N_c\to\infty$, i.e. in the case with an infinite number of colored quarks. In the plane of parameters $\mu_I,\mu$ a rather rich phase structure is found, which contains phases with and without pion condensation. Moreover, we have found a great variety of one-quark excitations of these phases, including gapless and gapped quasiparticles.