Third Order Tree Contributions in the Causal Approach

TL;DR

This paper investigates third-order tree contributions in the causal approach to quantum field theory, demonstrating that these contributions do not introduce anomalies in pure Yang-Mills models and extending gauge invariance properties.

Contribution

It provides a generalized form of gauge invariance showing that third-order tree contributions do not produce anomalies in the causal perturbation framework.

Findings

Tree contributions at third order do not generate anomalies.

A more general gauge invariance form is established.

The results apply to pure Yang-Mills models.

Abstract

We consider the general framework of perturbative quantum field theory for the pure Yang-Mills model developed in [9] and prove that the tree contributions do not give anomalies. We will provide a more general form of this gauge invariance property.