Gap and Bethe-Salpeter equations in Coulomb gauge

TL;DR

This paper explores the gap and Bethe-Salpeter equations in Coulomb gauge QCD, revealing insights into chiral symmetry breaking, heavy quark limits, and meson properties through nonperturbative analysis.

Contribution

It introduces a leading order truncation scheme for these equations, clarifies charge conservation and infrared divergence cancellation, and provides numerical results for meson masses and decay constants.

Findings

Quark gap equation shows chiral symmetry breaking and heavy quark limit reproduction.

Gluon equation admits a massive solution with nonperturbative renormalization.

Numerical results for meson masses and leptonic decay constants are presented.

Abstract

I will discuss the gap and Bethe-Salpeter equations for quantum chromodynamics in Coulomb gauge under a leading order truncation scheme. Within this scheme, the role of charge conservation and the cancellation of infrared divergences becomes particularly clear. The quark gap equation exhibits not only chiral symmetry breaking, but explicitly reproduces the heavy quark limit. The corresponding gluon equation has a massive solution with interesting nonperturbative renormalization properties. I will further discuss various aspects of the Bethe-Salpeter equation for pseudoscalar and vector mesons with arbitrary quark masses and present numerical results for the meson masses and leptonic decay constants.