Higgs effective $Hl_il_j$ vertex from heavy $\nu_R$ and applications to LFV phenomenology

TL;DR

This paper computes the Higgs-lepton flavor violating vertex induced by heavy right-handed neutrinos at one-loop level within Low Scale Seesaw Models, providing analytical formulas and phenomenological insights.

Contribution

It introduces a new analytical computation of the Higgs LFV vertex from heavy neutrinos in Low Scale Seesaw Models, using the Mass Insertion Approximation.

Findings

Derived a closed-form analytical expression for the $Hl_il_j$ vertex.

Applied the results to phenomenological LFV processes involving the Higgs.

Provided insights into the impact of heavy neutrinos on LFV phenomenology.

Abstract

We present a new computation of the Lepton Flavor Violating effective vertex involving the Higgs boson and two leptons with different flavors. This vertex is generated from the integration to one-loop level of the heavy right handed neutrinos which are considered here within the context of the Low Scale Seesaw Models and with masses close to the TeV scale. We apply the Mass Insertion Approximation technique to compute the loop contributions from these heavy $\nu_R$ and derive a symple analytical formula for the $Hl_il_j$ effective vertex in terms of the input $Y_\nu$ Yukawa coupling matrix and right handed $M_R$ neutrino masses. Some interesting phenomenological applications of this $Hl_il_j$ effective vertex are also included.