Implications of strict gauge invariance for particle spectra and precision observables

TL;DR

This paper explores how strict gauge invariance in field theory could cause subtle deviations in precision measurements of the Standard Model, with potential implications for future collider experiments.

Contribution

It elucidates the mechanism by which gauge invariance affects observable states and estimates its impact on the R ratio at future linear colliders.

Findings

Small deviations in precision tests due to gauge invariance

Implications for the R ratio at future colliders

Observable state structure differs from standard perturbation theory

Abstract

The discovery of the Higgs together with the excellent performance of the LHC allow to make precision tests of Brout-Englert-Higgs Physics, and especially its underlying field-theory. In this field theory strict gauge-invariance requires observable states to have a more involved structure than assumed in standard perturbation theory. This can lead to, likely rather very small, deviations in precision tests of the standard model. Here, the mechanism behind these deviations will be elucidated, and, as an example, its possible implications for the R ratio at future linear colliders will be estimated.