Perturbative gauge invariance: the electroweak theory

TL;DR

This paper generalizes the concept of perturbative gauge invariance to massive gauge fields, specifically applied to the electroweak theory, fixing couplings and deriving key features consistent with the standard model.

Contribution

It extends perturbative gauge invariance to massive gauge fields, providing a novel derivation of electroweak couplings and mass ratios without starting from massless fields.

Findings

Couplings of scalar and ghost fields are fixed.

W/Z mass ratio is derived.

Chiral nature of fermions is established.

Abstract

The concept of perturbative gauge invariance formulated exclusively by means of asymptotic fields is generalized to massive gauge fields. Applying it to the electroweak theory leads to a complete fixing of couplings of scalar and ghost fields and of the coupling to leptons, in agreement with the standard theory. The W/Z mass ratio is also determined, as well as the chiral character of the fermions. We start directly with massive gauge fields and leptons and, nevertheless, obtain a theory which satisfies perturbative gauge invariance.