Leptonic contributions to the effective electromagnetic coupling at four-loop order in QED

TL;DR

This paper calculates four-loop quantum electrodynamics corrections to the effective electromagnetic coupling's running, which is crucial for precision electroweak measurements and Standard Model constraints.

Contribution

It provides the first complete four-loop QED calculation of the electromagnetic coupling's running, enhancing the precision of theoretical predictions.

Findings

Four-loop corrections significantly impact the effective electromagnetic coupling.

Numerical evaluation of gauge invariant subsets confirms the magnitude of corrections.

Results improve the accuracy of electroweak precision tests.

Abstract

The running of the effective electromagnetic coupling is for many electroweak observables the dominant correction. It plays an important role for deriving constraints on the Standard Model in the context of electroweak precision measurements. We compute the four-loop QED corrections to the running of the effective electromagnetic coupling and perform a numerical evaluation of the different gauge invariant subsets.