Soft breaking of BRST invariance for introducing non-perturbative infrared effects in a local and renormalizable way

TL;DR

This paper explores a method to incorporate non-perturbative infrared effects into gauge theories by softly breaking BRST invariance, enabling a unified treatment of infrared and ultraviolet regimes.

Contribution

It introduces a novel approach using BRST doublets and massive parameters to softly break BRST invariance, reproducing the Gribov-Zwanziger action and modeling quark mass generation.

Findings

Reproduces the Gribov-Zwanziger action

Models dynamical quark mass generation

Distinguishes infrared from ultraviolet regimes

Abstract

The possibility of introducing non-perturbative infrared effects leading to a modification of the long distance behavior of gauge theories through a soft breaking of the BRST invariance is investigated. The method reproduces the Gribov-Zwanziger action describing the restriction of the domain of integration in the Feynman path integral to the Gribov region and a model for the dynamical quark mass generation is presented. The soft symmetry breaking relies on the introduction of BRST doublets and massive physical parameters, which allow one to distinguish the infrared region from the ultraviolet one, within the same theory.