Effects of the low lying Dirac modes on the spectrum of ground state mesons

TL;DR

This study investigates how removing low-lying Dirac eigenmodes affects the meson spectrum in QCD, revealing partial chiral symmetry restoration without impacting confinement.

Contribution

It introduces a method to exclude low Dirac modes in quark propagators and analyzes their impact on meson correlators and spectrum.

Findings

Degeneracies appear in the meson spectrum after mode exclusion

Chiral symmetry is partially restored in the valence sector

Confinement remains unaffected by the mode removal

Abstract

The lowest eigenmodes of the Dirac operator are related to the dynamical breaking of the chiral symmetry in Quantum Chromodynamics (QCD). In our work we construct quark propagators which exclude a varying number of the lowest Dirac eigenmodes and study the influence thereof on meson correlators and the meson spectrum. That procedure partially restores the chiral symmetry (in the valence sector) and we observe degeneracies in the spectrum while confinement seems not to be affected.