Phases of a strongly coupled four-fermion theory

TL;DR

This paper investigates a four-dimensional lattice four-fermion theory, revealing a symmetric strong-coupling phase with a mass gap and a narrow transition region with long-range correlations, contributing to understanding non-perturbative fermion dynamics.

Contribution

It provides new insights into the phase structure of a strongly coupled four-fermion lattice theory with SU(4) symmetry, highlighting a symmetric mass gap phase without symmetry breaking.

Findings

Identification of a symmetric strong-coupling phase with a mass gap

Discovery of a narrow transition region with long-range correlations

Observation of phase separation without symmetry breaking

Abstract

We present ongoing investigations of a four-dimensional lattice field theory with four massless reduced staggered fermions coupled through an SU(4)-invariant four-fermion interaction. As in previous studies of four-fermion and Higgs--Yukawa models with different lattice fermion discretizations, we observe a strong-coupling phase in which the system develops a mass gap without breaking any lattice symmetry. This symmetric strong-coupling phase is separated from the symmetric weak-coupling phase by a narrow region of four-fermi coupling in which the system exhibits long-range correlations.