The $\gamma \gamma$ decay of the Higgs boson in FDR

TL;DR

This paper demonstrates the effectiveness of the Four Dimensional Regularization scheme (FDR) by calculating the Higgs boson decay into two photons at one loop, confirming gauge invariance and consistency with standard methods.

Contribution

It presents the first complete calculation of a physical process within FDR, validating its gauge invariance and practical applicability to multi-loop calculations.

Findings

FDR yields results identical to standard methods for Higgs decay.

The calculation confirms FDR's gauge invariance in a non-trivial process.

Provides insights into handling fermions within FDR.

Abstract

We review the first complete calculation performed within the Four Dimensional Regularization scheme (FDR), the recently-proposed approach for addressing multi-loop calculations, which is simultaneously free of infinities and gauge-invariant in 4 dimensions. As a case study, the 1-loop-induced amplitude for the Higgs boson decay into two photons was calculated in arbitrary gauge. The result obtained, identical to that assessed with standard methods, stands as an explicit test of the gauge-invariance property of FDR. Moreover, the calculation provides an insight into the use of the technique, in particular in the presence of fermions.