Light quark contributions to Higgs decays

TL;DR

This paper demonstrates that light quark contributions to Higgs decay processes are nullified by non-perturbative effects, contrasting with leptons whose contributions are negligible due to small mass-dependent couplings.

Contribution

It reveals that non-perturbative effects eliminate light quark contributions to specific Higgs decay channels, challenging previous assumptions based on perturbative calculations.

Findings

Light quark contributions are zero in Higgs decays due to non-perturbative effects.

Lepton contributions remain negligible because of their small coupling.

The result impacts the understanding of Higgs decay mechanisms.

Abstract

The literature establishes that the light fermions contributions to the decays $H\to Z\gamma$ and $H\to\gamma\gamma$ are negligible since their coupling with the Higgs is proportional to $m_f$. In the present letter, we show that although such a conclusion is true for leptons, the light quark contributions are zero when we consider their non-perturbative effects.