Dark origins of matter-antimatter asymmetry

In a non-minimal Higgs framework, we present a novel mechanism in which the CP violating dark particles only interact with the SM through the gauge bosons, primarily the Z boson. Such Z-portal dark CP violation is realised in the regions of the parameter space where Higgs-mediated (co)annihilation processes are sub-dominant and have negligible contributions to the DM relic density. We show that in these regions of the parameter space, the Z portal CP violating DM can still thermalise and satisfy all experimental and observational data. We discuss the implications of such phenomena for electroweak baryogenesis. © 2019 Sissa Medialab Srl. All rights reserved.