Massless Decoupled Doublers: Chiral Yukawa Models and Chiral Gauge Theories

TL;DR

This paper introduces a novel lattice regularization method for chiral theories that decouples unwanted fermion replicas, maintaining gauge invariance in the continuum limit and addressing longstanding issues in chiral gauge theories.

Contribution

A new regularization technique for chiral theories on the lattice that decouples massless doublers and preserves gauge invariance in the continuum limit.

Findings

Continuum limit with a single fermion achieved in perturbation theory.

Identification of a symmetry related to decoupling of replicas non-perturbatively.

Method shares characteristics with the Rome approach for gauge invariance issues.

Abstract

We present a new method for regularizing chiral theories on the lattice. The arbitrariness in the regularization is used in order to decouple massless replica fermions. A continuum limit with only one fermion is obtained in perturbation theory and a Golterman-Petcher like symmetry related to the decoupling of the replicas in the non-perturbative regime is identified. In the case of Chiral Gauge Theories gauge invariance is broken at the level of the regularization, so our approach shares many of the characteristics of the Rome approach.