Lepton flavor violating $Z$ and Higgs decays in the scotogenic model

TL;DR

This paper investigates lepton flavor violating decays of Z and Higgs bosons within the scotogenic model, calculating branching ratios and analyzing their compatibility with experimental constraints.

Contribution

It provides the first detailed calculation of LFV Z and Higgs decay branching ratios in the scotogenic model, considering neutrino oscillation data and experimental bounds.

Findings

Branching ratios for Z and Higgs LFV decays can reach up to 10^{-8} and 10^{-3} respectively.

Constraints from non-observation of certain decays suppress these ratios by about 10^{-7}.

The results highlight potential observability of LFV decays within current experimental sensitivities.

Abstract

In this work, we have studied lepton flavor violating (LFV) decays of $Z$ gauge boson and Higgs boson ($H$) in the scotogenic model. We have computed branching ratios for the decays $Z\to\ell_\alpha\ell_\beta$ and $H\to\ell_\alpha\ell_\beta$ in this model. Here, $\ell_\alpha$ and $\ell_\beta$ are different charged lepton fields. After fitting to the neutrino oscillation observables in the scotogenic model, we have found that the branching ratios for the LFV decays of $Z$ and $H$ can be as large as $\sim10^{-8}$ and $\sim10^{-3}$ respectively. However, after satisfying the constraints due to non-observation of $\ell_\alpha\to\ell_\beta\gamma$ decays, the above mentioned branching ratio results are found to be suppressed by a factor of $\sim10^{-7}$.