Chiral phase transition in a lattice fermion--gauge--scalar model with U(1) gauge symmetry

TL;DR

This paper investigates the nature of the chiral phase transition in a lattice fermion-gauge-scalar model with U(1) symmetry, revealing different scaling behaviors at strong coupling and near a tricritical point, relevant for understanding fermion mass generation.

Contribution

It provides a numerical analysis of the chiral phase transition in a lattice model with U(1) gauge symmetry, highlighting the change in transition order and scaling near a tricritical point.

Findings

Second order transition at very strong coupling with NJL-like scaling

Different scaling behavior near the tricritical point

Potential implications for continuum limit and fermion mass generation

Abstract

The chiral phase transition induced by a charged scalar field is investigated numerically in a lattice fermion-gauge-scalar model with U(1) gauge symmetry, proposed recently as a model for dynamical fermion mass generation. For very strong gauge coupling the transition is of second order and its scaling properties are very similar to those of the Nambu--Jona-Lasinio model. However, in the vicinity of the tricritical point at somewhat weaker coupling, where the transition changes the order, the scaling behavior is different. Therefore it is worthwhile to investigate the continuum limit of the model at this point.