Effect of Transverse Gluons on Chiral Restoration in Excited Mesons

TL;DR

This paper investigates how transverse gluons influence chiral symmetry restoration in excited mesons using a Coulomb gauge QCD model, revealing that symmetry is restored at high spins and the gluon effect diminishes with increasing spin.

Contribution

It introduces a comprehensive analysis of transverse gluons' impact on chiral symmetry in excited mesons within a Coulomb gauge QCD framework, including derivation of meson spectra for various spins.

Findings

Chiral and axial symmetries are restored at large spins.

Degeneracy of meson multiplets with the same spin is observed.

Transverse gluon effects decrease rapidly as spin increases.

Abstract

The effect of transverse gluons on the chiral symmetry patterns of excited mesons is studied in a Coulomb gauge QCD model. The linear rising static quark-antiquark potential and the transverse gluon propagator known from lattice studies are input into the model. The non-perturbative quark propagator, which enters the meson bound state equations, is derived from the Dyson--Schwinger equations and a complete set of mesons for general spin quantum number is presented. From analyzing the bound state equations for large spins it is demonstrated, that chiral and axial symmetry are restored. In this limit a complete degeneracy of all multiplets with given spin is observed. The effect of the transverse gluon interaction is shown to vanish rapidly as the spin quantum number is increased. For vanishing dynamical quark mass the expected meson degeneracies are recovered.