General one-loop formulas for $H\rightarrow f\bar{f}\gamma$ and its applications

TL;DR

This paper derives general one-loop formulas for the decay process $H\rightarrow f\bar{f}\gamma$, applicable to various beyond Standard Model theories, and analyzes their phenomenological implications for future collider experiments.

Contribution

It provides a comprehensive set of analytic formulas for one-loop decay amplitudes in extended models, enabling precise numerical calculations with LoopTools.

Findings

New physics effects are sizable in decay rates.

Formulas are applicable to multiple beyond Standard Model scenarios.

Decay processes can be probed at future colliders.

Abstract

We present general one-loop contributions to the decay processes $H\rightarrow f\bar{f}\gamma$ including all possible the exchange of the additional heavy vector gauge bosons, heavy fermions, and charged (also neutral) scalar particles in the loop diagrams. As a result, the analytic results are valid in a wide class of beyond the standard models. Analytic formulas for the form factors are expressed in terms of Passarino-Veltman functions in the standard notations of {\tt LoopTools}. Hence, the decay rates can be computed numerically by using this package. The computations are then applied to the cases of the standard model, $U(1)_{B-L}$ extension of the standard model as well as two Higgs doublet model. Phenomenological results of the decay processes for all the above models are studied. We observe that the effects of new physics are sizable contributions and these can be probed at future colliders.