On the role of the subsidiary fields in the momentum and angular momentum in covariantly quantized QED and QCD

TL;DR

This paper clarifies the role of subsidiary gauge-fixing and ghost fields in the energy-momentum, momentum, and angular momentum operators in covariantly quantized QED and QCD, reaffirming previous key results despite recent criticisms.

Contribution

It demonstrates that the main results from earlier studies remain valid despite recent critiques, clarifying the role of subsidiary fields in quantum gauge theories.

Findings

Key results from Leader 2011a are unaffected by Damski's criticism.

The role of subsidiary fields in energy-momentum tensor is clarified.

Previous angular momentum analyses in QED and QCD are reaffirmed.

Abstract

The covariant quantization of QED and QCD requires the introduction of subsidiary gauge-fixing and ghost fields and it is crucial to understand the role of these in the energy-momentum tensor, and in the momentum and angular momentum operators. These issues were studied in \cite{Leader:2011za}, and key results from this study were utilized in the major review of angular momentum in \cite{Leader:2013jra}. Damski \cite{Damski:2021feu} has rightly criticized as incorrect the derivation of certain equations in \cite{Leader:2011za}. We show, however, that the key results of \cite{Leader:2011za} which are utilized in \cite{Leader:2013jra} are unaffected by Damski's criticism.