H. H. Phuong | Searcharxiv

arXiv2020

Lepton flavor violating decays of the SM-like Higgs boson $h\rightarrow e_ie_j$, and $e_i \rightarrow e_j\, γ$ in a flipped 3-3-1 model

In the framework of the flipped 3-3-1 model introduced recently [1], the lepton-flavor-violating (LFV) decay $μ\rightarrow 3e$ was predicted to have a large branching ratio (Br) close to the recent experimental limit. We will show that the Br of LFV decays of the standard-model-like (SM-like) Higgs boson decays (LFVHD) Br$(h\rightarrow e_ae_b)$ may also be large. Namely, the Br$(h\rightarrow μτ,eτ)$ can reach values of $\mathcal{O}(10^{-4})-\mathcal{O}(10^{-5})$, which will reach the upcoming experimental sensitivities. On the other hand, for LFV decays of charged leptons (cLFV) $(e_b\rightarrow e_aγ)$, the branching ratios are well below experimental bounds.

hep-ph↗

arXiv2019

Neutral Higgs decays $H \rightarrow Z γ,γγ$ in 3-3-1 models

The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $γγ$ and $Zγ$ will be discussed in the framework of the 3-3-1 models based on a recent work~\cite{Okada:2016whh}, where the Higgs sector becomes effectively the same as that in the two Higgs doublet models (2HDM) after the first symmetry breaking from $SU(3)_L$ scale into the electroweak scale. For large $SU(3)_L$ scale $v_3\simeq10$ TeV, dominant one-loop contributions to the two decay amplitudes arise from only the single charged Higgs boson predicted by the 2HDM, leading to that experimental constraint on the signal strength $μ^{331}_{γγ}$ of the Standard Model-like Higgs boson decay $h\rightarrow γγ$ will result in a strict upper bound on the signal strength $μ^{331}_{Zγ}$ of the decay $h\rightarrow\, Zγ$. For a particular model with lower $v_3$ around 3 TeV, contributions from heavy charged gauge and Higgs bosons may have the same order, therefore may give strong destructive or constructive correlations. As a by-product, a deviation from the SM prediction $|μ^{331}_{γγ}-1| \le 0.04$ still allows $|μ^{331}_{Zγ}-1|$ to reach values near 0.1. We also show that there exists an $CP$-even neutral Higgs boson $h^0_3$ predicted by the 3-3-1 models, but beyond the 2HDM, has an interesting property that the branching ratio Br$(h^0_3\rightarrow γγ)$ is very sensitive to the parameter $β$ used to distinguish different 3-3-1 models.

hep-ph↗