Generation of neutrino mass from new physics at TeV scale and multilepton signatures at the LHC

Abstract

In this paper we consider the generation of naturally small neutrino masses from a dimension-7 operator. Such a term can arise in the presence of a scalar quadruplet and a pair of vectorlike fermion triplets and enables one to obtain small neutrino masses through the TeV scale linear seesaw mechanism. We study the phenomenology of the charged scalars of this model, in particular, the multilepton signatures at the Large Hadron Collider. Of special importance is the presence of the same-sign-tri-lepton signatures originating from the triply charged scalars. The Standard Model background for such processes is small, and hence this is considered as a confirming evidence of new physics. We also looked for events with three, four, five, and six leptons that have negligible contamination from the Standard Model. We further point out the spectacular lepton flavor violating the four-lepton signal that can be the hallmark for these types of models. We also compute the added contributions in the rate for the Standard Model Higgs decaying to two photons via the charged scalars in this model.