Wilson Fermions with Four Fermion Interactions

TL;DR

This paper investigates the lattice formulation of the Nambu Jona-Lasinio model with Wilson fermions, focusing on spontaneous chiral symmetry breaking, relevant for understanding fermion mass generation and composite dynamics in beyond Standard Model theories.

Contribution

It provides the first lattice study of the NJL model using Wilson fermions, exploring chiral symmetry breaking in this context.

Findings

Evidence of spontaneous chiral symmetry breaking on the lattice.

Insights into how four-fermion interactions influence fundamental dynamics.

Potential implications for models of dynamical electroweak symmetry breaking.

Abstract

We present a lattice study of a four fermion theory, known as Nambu Jona-Lasinio (NJL) theory, via Wilson fermions. Four fermion interactions naturally occur in several extensions of the Standard Model as a low energy parameterisation of a more fundamental theory. In models of dynamical electroweak symmetry breaking these operators, at an effective level, are used to endow the Standard Model fermions with masses. Furthermore these operators, when sufficiently strong, can drastically modify the fundamental composite dynamics by, for example, turning a strongly coupled infrared conformal theory into a (near) conformal one with desirable features for model building. As first step, we study spontaneous chiral symmetry breaking for the lattice version of the NJL model.