General one-loop contributions to the decay $H\rightarrow \nu_l\bar{\nu}_l\gamma$

TL;DR

This paper provides comprehensive one-loop calculations for the decay of the Higgs boson into neutrinos and a photon, including potential contributions from new heavy particles, with results applicable to models beyond the Standard Model.

Contribution

It presents general analytical formulas for the decay amplitude considering all possible heavy particle contributions, extending previous calculations to include extra neutrinos and new physics scenarios.

Findings

Results are consistent with previous Standard Model computations.

Analytical expressions are provided in Passarino-Veltman functions for numerical evaluation.

Phenomenological analysis at the LHC using updated parameters.

Abstract

General one-loop contributions to the decay amplitudes $H\rightarrow \nu_l\bar{\nu}_l\gamma$ are presented, considering all possible contributions of additional heavy vector gauge bosons, fermions, and charged (and also neutral) scalar particles appearing in the loop diagrams. Moreover, the results can be applied directly when extra neutrinos (apart from three ones in standard model) are taken into account in final states. Analytic results are presented in terms of Passarino-Veltman scalar functions which can be evaluated numerically using {\tt LoopTools}. In the standard model framework, these analytical results are generated and cross-checked with previous computations. We find that our results are well consistent with these computations. Within standard model limit, phenomenological results for the decay channels are also studied using the updated input parameters at the Large Hadron Collider.