Compact QED3 with theta term and axionic confining strings

TL;DR

This paper investigates three-dimensional compact QED with an axionic theta term, showing that the vacuum energy and Wilson loop behavior are largely independent of theta, and explores properties of axionic confining strings.

Contribution

It introduces a variational gauge invariant approach to analyze the effects of the theta term in compact QED3, revealing independence of certain physical quantities from theta and discussing confining string properties.

Findings

Ground state energy is independent of theta in leading approximation.

Wilson loop obeys the area law, indicating confinement.

Mass gap of the axionic field depends on theta.

Abstract

We discuss three dimensional compact QED with a theta term due to an axionic field. The variational gauge invariant functional is considered and it is shown that the ground state energy is independent of theta in a leading approximation. The mass gap of the axionic field is found to be dependent upon theta, the mass gap of the photon field and the scalar potential. The vacuum expectation of the Wilson loop is shown to be independent of theta in a leading approximation, to obey the area law and to lead to confinement. We also briefly discuss the properties of axionic confining strings.