# Lepton flavor violating Higgs boson decays in seesaw models: new discussions

## TL;DR

This paper analyzes lepton flavor violating Higgs decays in seesaw models at one-loop level, providing detailed calculations and comparisons for branching ratios across different models and neutrino mass scales.

## Contribution

It offers new analytic expressions for LFVHD branching ratios in seesaw models and compares results across gauges and models, revealing relations between MSS and ISS predictions.

## Key findings

- Maximal branching ratio around 10^{-11} in minimal seesaw.
- Branching ratio increases with neutrino mass scale m_{n_6}.
- Ratio of LFVHD rates in ISS and MSS models depends on m_{n_6} and x_X.

## Abstract

The lepton flavor violating decay of the Standard Model-like Higgs boson (LFVHD), h->\mu\tau, is discussed in seesaw models at the one-loop level. Based on particular analytic expressions of Passarino-Veltman functions, the two unitary and 't Hooft Feynman gauges are used to compute the branching ratio of LFVHD and compare with results reported recently. In the minimal seesaw (MSS) model, the branching ratio was investigated in the whole valid range 10^{-9}-10^{15} GeV of new neutrino mass scale m_{n_6}. Using the Casas-Ibarra parameterization, this branching ratio enhances with large and increasing m_{n_6}. But the maximal value can reach only order of 10^{-11}. Interesting relations of LFVHD predicted by the MSS and inverse seesaw (ISS) model are discussed. The ratio between two LFVHD branching ratios predicted by the ISS and MSS is simply m^2_{n_6}\mu^{-2}_X, where \mu_X is the small neutrino mass scale in the ISS. The consistence between different calculations is shown precisely from analytical approach.