Fermion mass without symmetry breaking

TL;DR

This paper investigates a 3D fermion model with four-fermion interactions that can generate a mass gap without symmetry breaking, supported by theoretical and numerical evidence of a continuous phase transition.

Contribution

It demonstrates the possibility of fermion mass generation without symmetry breaking in a three-dimensional four-fermion model, expanding understanding of mass gap formation.

Findings

Mass gap develops at strong coupling

No fermion bilinear condensate forms

Massless and massive phases separated by continuous transition

Abstract

We examine a model of reduced staggered fermions in three dimensions interacting through an $SO(4)$ invariant four fermion interaction. The model is similar to that considered in a recent paper by Ayyer and Chandrasekharan \cite{Ayyar:2014eua}. We present theoretical arguments and numerical evidence which support the idea that the system develops a mass gap for sufficiently strong four fermi coupling.{\it without} producing a symmetry breaking fermion bilinear condensate. Massless and massive phases appear to be separated by a continuous phase transition.