Investigation of anomalous axial QED

TL;DR

This paper investigates whether gauge invariance can be preserved in anomalous axial QED using nonlocal counterterms and finds that unitarity is violated, challenging recent claims to the contrary.

Contribution

It provides an explicit analysis of Feynman diagrams demonstrating unitarity violation in anomalous axial QED with nonlocal counterterms.

Findings

Unitarity is violated in axial QED with nonlocal counterterms.

Gauge invariance can be maintained despite anomalies.

Contradicts recent claims that unitarity remains intact.

Abstract

Although axial QED suffers from a gauge anomaly, gauge invariance may be maintained by the addition of a nonlocal counterterm. Such nonlocal conterterms, however, are expected to ruin unitarity of the theory. We explicitly investigate some relevant Feynman diagrams and show that, indeed, unitarity is violated, contrary to recent claims.