Imprints of massive inverse seesaw model neutrinos in lepton flavor violating Higgs boson decays

Abstract

In this paper we consider a Higgs boson with mass and other properties compatible with those of the recently discovered Higgs particle at the LHC, and explore the possibility of new Higgs leptonic decays, beyond the standard model, with the singular feature of being lepton flavor violating (LFV). We study these LFV Higgs decays, H → l klm , within the context of the inverse seesaw model (ISS) and consider the most generic case where three additional pairs of massive right-handed singlet neutrinos are added to the standard model particle content. We require in addition that the input parameters of this ISS model are compatible with the present neutrino data and other constraints, like perturbativity of the neutrino Yukawa couplings. We present a full one-loop computation of the BRðH → l klm Þ rates for the three possible channels, l klm ¼ μτ, eτ, eμ, and analyze in full detail the predictions as functions of the various relevant ISS parameters. We study in parallel the correlated one-loop predictions for the radiative decays, l m → l k γ, within this same ISS context, and require full compatibility of our predictions with the present experimental bounds for the three radiative decays, μ → eγ, τ → μγ, and τ → eγ. After exploring the ISS parameter space we conclude on the maximum allowed LFV Higgs decay rates within the ISS.

Analysis of the h, H, A → τμ decays induced from SUSY loops within the Mass Insertion Approximation

“…Several examples where the neutrino Yukawa couplings, which can be large if neutrinos are Majorana fermions, are the responsible for generating these LFVHD have been explored in the literature. The issue of LFVHD being radiatively generated from loops with neutrinos was first explored in a non-SUSY context [48], and later other cases were considered, including the case of the type-I seesaw model both with and without SUSY [37], the inverse seesaw model [13] and its SUSY version [47]. The study of LFVHD within the more general context of Non-Minimal-Flavor Violation (NMFV) of the MSSM has also a long story.…”

Electron electric dipole moment in Inverse Seesaw models

“…Extensions of the SM with sterile fermions, which accommodate oscillation data, may also have an impact on other observables, such as charged lepton flavour violation (cLFV) in Higgs [34][35][36], neutral Z boson [37][38][39] and meson decays [40][41][42][43][44]. Sterile fermions may also contribute to lepton flavour conserving observables such as the dipole moments of charged leptons [45][46][47].…”

Effect of steriles states on lepton magnetic moments and neutrinoless double beta decay

“…Depending on their mass (which can range from well below the electroweak to the Planck scale), and more importantly, on their mixing with the active neutrinos, the sterile fermions can lead to non-negligible modifications of the leptonic charged current interaction (W ν), which would be manifest in electroweak (EW) interactions as a deviation from unitarity of the leptonic mixing matrix [12,13]; in turn this will have an impact on numerous observables, providing contributions to lepton flavour violating (LFV) processes [14][15][16][17], leading to the violation of lepton flavour universality (LFU) [18][19][20][21], and enhancing rare leptonic (tau) decays, leptonic and semi-leptonic meson decays [22], also impacting invisible Z-boson [23] and Higgs boson decays [24][25][26][27][28].…”