Centre vortex removal restores chiral symmetry

TL;DR

This study demonstrates that centre vortices are essential for dynamical chiral symmetry breaking in SU(3) gauge theory, as vortex-only configurations reproduce the hadron spectrum and vortex removal restores chiral symmetry.

Contribution

First use of chiral overlap fermions to analyze the low-lying hadron spectrum on vortex-modified lattice gauge fields, confirming vortices' role in chiral symmetry breaking.

Findings

Vortex-only configurations reproduce the hadron spectrum features.

Vortex removal leads to chiral symmetry restoration.

Heavy quark masses show weakly-interacting quark behavior.

Abstract

The influence of centre vortices on dynamical chiral symmetry breaking is investigated through the light hadron spectrum on the lattice. Recent studies of the quark propagator and other quantities have provided evidence that centre vortices are the fundamental objects underpinning dynamical chiral symmetry breaking in SU(3) gauge theory. For the first time, we use the chiral overlap fermion action to study the low-lying hadron spectrum on lattice ensembles consisting of Monte Carlo, vortex-removed, and vortex-projected gauge fields. We find that gauge field configurations consisting solely of smoothed centre vortices are capable of reproducing all the salient features of the hadron spectrum, including dynamical chiral symmetry breaking. The hadron spectrum on vortex-removed fields shows clear signals of chiral symmetry restoration at light values of the bare quark mass, while at heavy masses the spectrum is consistent with a theory of weakly-interacting constituent quarks.