Higgs Decays in the Low Scale Type I See-Saw Model

TL;DR

This paper investigates the potential for exotic Higgs decays into neutrinos within the low scale type I see-saw model, considering experimental constraints and prospects for detection at the LHC.

Contribution

It demonstrates that despite strict constraints, a sizable Higgs decay into a light and a heavy neutrino remains possible and explores its detectability at the LHC.

Findings

Exotic Higgs decay channels are allowed with sizable branching ratios.

Prospects for observing these decays at the LHC are promising.

Complementarity with $oldsymbol{ ext{μ→eγ}}$ decay searches is discussed.

Abstract

The couplings of the low scale type I see-saw model are severely constrained by the requirement of reproducing the correct neutrino mass and mixing parameters, by the non-observation of lepton number and charged lepton flavour violating processes and by electroweak precision data. We show that all these constraints still allow for the possibility of an exotic Higgs decay channel into a light neutrino and a heavy neutrino with a sizable branching ratio. We also estimate the prospects to observe this decay at the LHC and discuss its complementarity to the indirect probes of the low scale type I see-saw model from experiments searching for the $\mu\to e\gamma$ decay.