Confinement effects from interacting chromo-magnetic and axion fields

TL;DR

This paper investigates how constant chromo-electric and chromo-magnetic background fields influence confinement in a non-Abelian gauge theory with axion-like coupling, revealing confinement only in the magnetic case.

Contribution

It demonstrates that a chromo-magnetic background induces a linear confining potential, a novel insight into confinement mechanisms in such gauge theories.

Findings

Chromo-electric background yields Coulomb potential.

Chromo-magnetic background results in Coulomb plus linear potential.

Linear potential indicates confinement of static charges.

Abstract

We study a non-Abelian gauge theory with a pseudo scalar coupling \phi \epsilon ^{\mu \nu \alpha \beta} F_{\mu \nu}^a F_{\alpha \beta}^a in the case where a constant chromo-electric, or chromo-magnetic, strength expectation value is present. We compute the interaction potential within the framework of gauge-invariant, path-dependent, variables formalism. While in the case of a constant chromo-electric field strength expectation value the static potential remains Coulombic, in the case of a constant chromo-magnetic field strength the potential energy is the sum of a Coulombic and a linear potentials, leading to the confinement of static charges.