Confining potential from interacting magnetic and torsion fields

TL;DR

This paper investigates how torsion fields coupled with photons influence static potentials, revealing Coulombic behavior with electric backgrounds and confining potentials with magnetic backgrounds, differing from axion-like particle interactions.

Contribution

It introduces a gauge-invariant formalism to analyze torsion-photon coupling, showing novel confining potentials in magnetic backgrounds, unlike standard axion-like interactions.

Findings

Coulomb potential in electric background

Confining potential in magnetic background

Distinct behavior from axion-photon coupling

Abstract

Adopting the gauge-invariant but path-dependent variables formalism, we study the coupling of torsion fields with photons in the presence of an external background electromagnetic. We explicitly show that, in the case of a constant electric field strength expectation value, the static potential remains Coulombic, while in the case of a constant magnetic field strength expectation value a confining potential is obtained. This result displays a marked qualitative departure from the usual coupling of axionlike particles with photons in the presence of an external magnetic field.