Loop Anomalies in the Causal Approach

TL;DR

This paper investigates one-loop anomalies in gauge models using the causal approach, showing their absence beyond order 4 and analyzing parity-related contributions at second and third order.

Contribution

It provides a detailed analysis of one-loop anomalies in gauge models within the causal approach, confirming known results and extending understanding of parity effects.

Findings

No one-loop anomalies for orders greater than 4

Even parity contributions do not produce anomalies

Reconfirmation of odd parity anomaly results

Abstract

We consider gauge models in the causal approach and study one-loop contributions to the chronological products and the anomalies they produce. We prove that in order greater than 4 there are no one-loop anomalies. Next we analyze one-loop anomalies in the second and third order of the perturbation theory. We prove that the even parity contributions (with respect to parity) do not produce anomalies; for the odd parity contributions we reobtain the well-known result.