Neutrino Mass and the Higgs Portal Dark Matter in the ESSFSM

Abstract

We extend the standard model with three right-handed singlet neutrinos and a real singlet scalar. We impose two Z2 and Z2′ symmetries. We explain the tiny neutrino mass-squared differences with two Z2- and Z2′-even right-handed neutrinos using type I seesaw mechanism. The Z2-odd fermion and the Z2′-odd scalar can both serve as viable dark matter candidates. We identify new regions in the parameter space which are consistent with relic density of the dark matter from recent direct search experiments LUX-2016 and XENON1T-2017 and LHC data.