Instanton molecules at high temperature - the Georgi-Glashow model and beyond

TL;DR

This paper investigates how instanton-anti-instanton molecules influence gauge theory correlators at high temperature, using the 2+1D Georgi-Glashow model and discussing implications for QCD.

Contribution

It demonstrates the sensitivity of certain correlators to instanton molecules at high temperature and clarifies their role in the axial U(1) anomaly in gauge theories.

Findings

Correlators are affected by instanton molecules even in the deconfined phase.

Calculated correlation functions in the Georgi-Glashow model reveal instanton effects.

Discussed implications for the axial anomaly in high-temperature QCD.

Abstract

We show that correlators of some local operators in gauge theories are sensitive to the presence of the instantons even at high temperature where the latter are bound into instanton-anti-instanton "molecules". We calculate correlation functions of such operators in the deconfined phase of the 2+1 dimensional Georgi-Glashow model and discuss analogous quantities in the chirally symmetric phase of QCD. We clarify the mechanism by which the instanton-anti-instanton molecules contribute to the anomaly of axial U(1) at high temperature.