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

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 the standard model) are taken into account in final states. Analytic results are expressed in terms of Passarino–Veltman scalar functions which can be evaluated numerically using $\texttt{LoopTools}$. 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 the standard model limit, phenomenological results for the decay channels are also studied using the present input parameters at the Large Hadron Collider. Lastly, the calculation is also applied to the Two Higgs Doublet Model framework as another example.