Axionic excitation from QCD Condensate

TL;DR

This paper proposes that inhomogeneous quark condensates can host axionic excitations linked to emergent gauge fields, with potential implications for understanding QCD phenomena involving flux tubes and anomalies.

Contribution

It introduces a novel framework connecting inhomogeneous quark condensates, emergent gauge symmetry, and axionic excitations through vortex configurations and axial anomaly effects.

Findings

Identification of an emergent gauge symmetry in inhomogeneous quark condensates.

Proposal that regular parts of the condensate act as axionic excitations.

Connection between flux tube-induced vortices and axionic phenomena in QCD.

Abstract

A complex order parameter is used for describing inhomogeneous quark condensate and its phase is decomposed into a regular part and a singular part. An emergent gauge symmetry is found to connect these two parts. The singular part plays the role of an emergent gauge field while the regular part can be considered as an axionic excitation, provided that the chromoelectric flux tube is capable of inducing a vortex configuration in the quark condensate, with the help of axial anomaly.