Revisiting the rare $H\to q_iq_j$ decays in the Standard Model

TL;DR

This paper recalculates the extremely rare Higgs decays to different quark pairs within the Standard Model, using a detailed expansion method to improve accuracy and clarify previous discrepancies.

Contribution

It introduces a Taylor series expansion approach for decay form factors, enhancing the precision of rare Higgs decay predictions and resolving inconsistencies with earlier studies.

Findings

Br(H→uc)=5.00×10⁻²⁰

Br(H→ds)=1.19×10⁻¹¹

Br(H→db)=5.16×10⁻⁹

Abstract

We revisit the rare decays of the Higgs boson to two different quarks in the Standard Model, which arise at the one-loop level. We perform Taylor series expansions to the complete form factors of the decay amplitudes, according to their different mass hierarchies, this allow us to take full advantage of the GIM mechanism to eliminate spurious contributions and retain those that truly contribute. We found that Br$(H\to uc)$=$5.00\times10^{-20}$, Br$(H\to ds)$=$1.19\times10^{-11}$, Br$(H\to db)$=$5.16\times10^{-9}$ and Br$(H\to sb)$=$1.15\times10^{-7}$. Our predictions for the $H\to uc,ds$ decays disagree with previous results in the literature.