Two-loop QCD corrections to Higgs radiative decay to vector quarkonium

TL;DR

This paper calculates two-loop QCD corrections to Higgs decay into vector quarkonium plus a photon, providing the most precise predictions to date for these rare decay processes.

Contribution

It introduces a comprehensive two-loop QCD correction calculation for Higgs radiative decay into vector quarkonium, improving theoretical accuracy.

Findings

Predicted branching ratio for H→J/ψ+γ: approximately 3.27×10^{-6}

Predicted branching ratio for H→Υ+γ: approximately 1.34×10^{-8}

Inclusion of destructive interference effects enhances prediction accuracy.

Abstract

The exclusive production of $J/\psi$ through Higgs boson radiative decay may serve a clean channel to extracting the charm quark Yukawa coupling. We calculate the two-loop QCD corrections to $H\rightarrow J/\psi(\Upsilon)+\gamma$ using an optimized nonrelativistic QCD (NRQCD) approach. We compute the ${\cal O}(\alpha_s^2)$ correction in the direct channel, where Higgs directly couples to $c\bar{c}$, as well as the ${\cal O}(\alpha_s)$ correction in the indirect channel, {\it viz.}, $H\to\gamma^*\gamma$ followed by the virtual photon fragmentation into $J/\psi$. Incorporating the destructive interference between the direct and indirect channels, we present to date the most accurate predictions for Higgs boson radiative decay into vector quarkonium, $\mathcal{B}(H\rightarrow J/\psi+\gamma) = 3.27_{-0.07}^{+0.30}{}^{+0.06}_{-0.06}{}_{-0.13}^{+0.13}\times 10^{-6}$, and $\mathcal{B}(H\rightarrow \Upsilon+\gamma)= 1.34_{-0.31}^{+0.75}{}^{+0.25}_{-0.20}{}^{+0.05}_{-0.05}\times 10^{-8}$.