Abstract

We revisit a Dark Matter model with an extension of the Standard Model with two real singlets chi and eta obeying a Z(2) circle times Z(2)' symmetry, where Z(2)' is broken spontaneously. While chi serves as a stable Dark Matter candidate providing the relic density, the real eta field plays the role of a light mediator. We study the viability of this model with respect to Dark Matter self-interactions which may explain the density profiles observed in dwarf galaxies up to scales of the size of our Milky Way. Moreover, the Standard Model-like Higgs boson of the model has a tiny mixing with the mediator field and appears to be consistent with current LHC data. In this rather minimal extension of the Standard Model the mediator eta decays naturally into Majorana neutrinos neither disturbing standard big bang nucleosynthesis nor cosmic microwave background observations. (C) 2019 The Author(s). Published by Elsevier B.V.