Origin of fermion masses without spontaneous symmetry breaking

TL;DR

This paper demonstrates that in a 3D lattice four-fermion model, fermions can acquire mass through interactions at a quantum critical point without spontaneous symmetry breaking, challenging traditional mass generation theories.

Contribution

It introduces a novel non-perturbative mechanism for fermion mass generation that does not rely on spontaneous symmetry breaking, supported by large-scale Monte Carlo simulations.

Findings

Massive fermions arise without symmetry breaking.

Mass generation occurs at a second order quantum critical point.

The mechanism is likely universal and broadly applicable.

Abstract

Using a simple three dimensional lattice four-fermion model we argue that massless fermions can become massive due to interactions without the need for any spontaneous symmetry breaking. Using large scale Monte Carlo calculations within our model, we show that this non-traditional mass generation mechanism occurs at a second order quantum critical point that separates phases with the same symmetries. Universality then suggests that the new origin for the fermion mass should be of wide interest.