$Gamma(H\to b\bar{b})$ to order $\alpha\alpha_s$

TL;DR

This paper calculates the decay rate of the Standard Model Higgs boson to bottom quarks including mixed electroweak and QCD corrections at order , revealing corrections comparable to pure QCD effects but with opposite sign.

Contribution

It provides the first computation of  order corrections to Higgs decay to bottom quarks using the optical theorem and asymptotic expansions.

Findings

 corrections are similar in magnitude to  QCD corrections.

The  corrections have opposite sign to  corrections.

The calculation employs three-loop corrections and asymptotic expansion techniques.

Abstract

We compute the decay rate of the Standard Model Higgs boson to bottom quarks to order $\alpha\alpha_s$. We apply the optical theorem and calculate the imaginary part of three-loop corrections to the Higgs boson propagator using asymptotic expansions in appropriately chosen mass ratios. The corrections of order $\alpha\alpha_s$ are of the same order of magnitude as the ${\cal O}(\alpha_s^3)$ QCD corrections but have the opposite sign.