UHM High Energy Physics Seminar

Neutrino mass from large Higgs multiplets and non-standard Higgs searches at the LHC

by Dr. Tathagata Ghosh (University of Hawaii)

Tuesday, 19 September 2017 from to (Pacific/Honolulu)
at WAT ( 112 )
It is well known that generating small neutrino masses with TeV scale new physics is challenging. In this talk, we discuss phenomenology of two such models, where small neutrino masses are successfully developed by n > 2 Higgs multiplets, with O(1-10 TeV) scale of new physics. First, we revisit a dimension seven neutrino mass generation mechanism based on the addition of an isospin 3/2 scalar quadruplet and two vector-like iso-triplet leptons to the standard model. We discuss the LHC phenomenology of the charged scalars of this model, complemented by the electroweak precision constraints. We pay particular attention to the triply charged and doubly charged components. We also discuss bounds on the model parameter space that arise from the measured decay rate of the Standard Model Higgs to a pair of photons. Next, we discuss the left-right symmetric model (LRSM) where neutrino masses are generated in a combination of Type-I and Type-II see-saw mechanisms. Type-II see-saw demands the presence of a scalar triplet. Here we discuss leptonic decays of the standard model-like Higgs boson at the LHC, that violate lepton flavor, in the context of LRSM. We present a guideline about how to achieve a relatively large branching ratio of the Higgs in the above channels assuming the right-handed scale is at 20 TeV. We also review various flavor changing processes that impose limits on flavor violating leptonic decays of the SM-like Higgs.