Lepton flavor violating decays of Standard-Model-like Higgs in 3-3-1 model with neutral lepton

TL;DR

This paper calculates the one-loop lepton flavor violating decay of the Higgs in a 3-3-1 model, finding that exotic leptons significantly enhance the decay rate, which can reach observable levels under certain parameters.

Contribution

It provides a detailed calculation of LFV Higgs decay in the 3-3-1 model, highlighting the role of exotic leptons and Yukawa couplings in the decay rate.

Findings

Exotic leptons contribute significantly to the decay rate.

Branching ratio can reach 10^{-5} with large Yukawa couplings.

Decay rate decreases with smaller Yukawa couplings and larger $v_3$.

Abstract

The one loop contribution to the lepton flavor violating decay $h^0\rightarrow \mu\tau$ of the SM-like neutral Higgs (LFVHD) in the 3-3-1 model with neutral lepton is calculated using the unitary gauge. We have checked in detail that the total contribution is exactly finite, and the divergent cancellations happen separately in two parts of active neutrinos and exotic heavy leptons. By numerical investigation, we have indicated that the one-loop contribution of the active neutrinos is very suppressed while that of exotic leptons is rather large. The branching ratio of the LFVHD strongly depends on the Yukawa couplings between exotic leptons and $SU(3)_L$ Higgs triplets. This ratio can reach $10^{-5}$ providing large Yukawa couplings and constructive correlations of the $SU(3)_L$ scale ($v_3$) and the charged Higgs masses. The branching ratio decreases rapidly with the small Yukawa couplings and large $v_3$.