Decay of standard model-like Higgs boson $h\rightarrow \mu\tau$ in a 3-3-1 model with inverse seesaw neutrino masses

TL;DR

This paper explores how an extended 3-3-1 model with inverse seesaw neutrino masses predicts enhanced lepton-flavor-violating Higgs decays, potentially observable with current experimental constraints.

Contribution

It demonstrates that the improved 3-3-1 models can produce significant Higgs decay signals of lepton flavor violation, which are suppressed in earlier versions.

Findings

Branching ratios of $h^0_1\rightarrow\mu\tau,e\tau$ can reach $10^{-5}$.

Decay rates increase to $10^{-4}$ near perturbative Yukawa limits.

Predictions are consistent with current $\\mu\rightarrow e\gamma$ decay constraints.

Abstract

By adding new gauge singlets of neutral leptons, the improved versions of the 3-3-1 models with right-handed neutrinos have been recently introduced in order to explain recent experimental neutrino oscillation data through the inverse seesaw mechanism. We prove that these models predict promising signals of lepton-flavor-violating decays of the standard-model-like Higgs boson $h^0_1\rightarrow \mu\tau,e\tau$, which are suppressed in the original versions. One-loop contributions to these decay amplitudes are introduced in the unitary gauge. Based on a numerical investigation, we find that the branching ratios of the decays $h^0_1\rightarrow\mu\tau,e\tau$ can reach values of $10^{-5}$ in the regions of parameter space satisfying the current experimental data of the decay $\mu\rightarrow e\gamma$. The value of $10^{-4}$ appears when the Yukawa couplings of leptons are close to the perturbative limit. Some interesting properties of these regions of parameter space are also discussed.