Baryogenesis from Dark Sector

Abstract

The measured Higgs mass value 125 GeV may suggest that standard model (SM) may be UV-complete up to Planck scale. Yet, questions of the nature of the dark matter and of the origin of baryons remain unsolved in the SM. The latter is particularily difficult to address in UV-complete low energy extensions of SM. The main problem is finding enough CP-violation consistent with existing laboratory bounds. I will show that a simple UV-complete model, with a fermionic dark matter particle X coupling to a new singlet scalar S can realize successful electroweak baryogenesis. In our model X gets a CP asymmetry that is transferred to the standard model through a CP portal interaction, coupling X to tau leptons and an inert Higgs doublet. The CP asymmetry induced in left-handed tau leptons biases sphalerons to produce the baryon asymmetry. The model has promising discovery potential at the LHC, while robustly providing a large enough baryon asymmetry and correct dark matter relic density with reasonable values of the couplings.