Scalar sector phenomenology of three-loop radiative neutrino mass models

We perform a phenomenological study of the scalar sector of two models that generate neutrino mass at the three-loop level and contain viable dark matter candidates. Both models contain a charged singlet scalar and a larger scalar multiplet (triplet or quintuplet). We investigate the effect of the extra scalars on the Higgs mass and analyze the modifications to the triple Higgs coupling. The new scalars can give observable changes to the Higgs decay channel h→γγ and, furthermore, we find that the electroweak phase transition becomes strongly first order in large regions of parameter space.