Remarks on confinement driven by axion-like particles in Yang-Mills theories

TL;DR

This paper investigates how axion-like particles influence confinement in Yang-Mills theories, revealing that mixed pseudoscalar and scalar couplings produce a potential with both Yukawa and linear components, indicating confinement.

Contribution

It demonstrates how pseudoscalar and scalar couplings affect confinement and screening in non-Abelian gauge theories using gauge-invariant formalism, with novel insights into potential profiles.

Findings

Mixed couplings lead to Yukawa plus linear potential profiles.

Pure pseudoscalar coupling results differ significantly.

Similar confinement features are observed in curved space-time contexts.

Abstract

Features of screening and confinement are studied for a non-Abelian gauge theory with a mixture of pseudoscalar and scalar coupling, in the case where a constant chromo-electric, or chromo-magnetic, strength expectation value is present. Our discussion is carried out using the gauge-invariant but path-dependent variables formalism. We explicitly show that the static potential profile is the sum of a Yukawa and a linear potential, leading to the confinement of static probe charges. Interestingly, similar results have been obtained in the context of gluodynamics in curved space-time. For only pseudoscalar coupling, the results are radically different.