The Higgs Sector in the Causal Approach

TL;DR

This paper analyzes the electroweak Higgs sector within the causal perturbation theory framework, deriving the most general interaction Lagrangian for multiple Higgs fields and exploring the implications for the Weinberg angle.

Contribution

It provides a quantum-field-theoretic derivation of the Higgs interaction Lagrangian for arbitrary Higgs fields, highlighting the non-uniqueness of the Weinberg angle.

Findings

Derived the general form of the Higgs interaction Lagrangian in the causal approach.

Showed that multiple Higgs fields lead to non-unique Weinberg angle values.

Performed the analysis up to second order in perturbation theory.

Abstract

We consider the electro-weak sector of the standard model up to the second order of the perturbation theory (in the causal approach) and derive the most general form of the interaction Lagrangian for an arbitrary number of Higgs fields. The analysis is done in a purely quantum setting. If more than one Higgs field is considered, the values of the Weinberg is not fixed uniquely.