Cheshire $\theta$ terms, Aharonov-Bohm effects, and axions

TL;DR

This paper explores special $ heta$ terms in field theories with vortices, showing they cause Aharonov-Bohm effects for particles like baryons and leptons near axion strings, revealing novel topological phenomena.

Contribution

It introduces the concept of Cheshire $ heta$ terms in theories with global vortices and demonstrates their role in inducing Aharonov-Bohm effects for particles around axion strings.

Findings

Cheshire $ heta$ terms can induce Aharonov-Bohm effects in field theories.

These effects occur for particles moving around axion strings.

The work connects topological terms with observable quantum phenomena.

Abstract

We discuss unusual $\theta$ terms that can appear in field theories that allow global vortices. These `Cheshire $\theta$ terms' induce Aharonov-Bohm effects for some particles that move around vortices. For example, a Cheshire $\theta$ term can appear in QCD coupled to an axion and induces Aharonov-Bohm effects for baryons and leptons moving around axion strings.