Dark matter phenomenology in Z'2 broken singlet extended 2HDM

Abstract: Many different approaches have been made to explain the nature of dark matter (DM), but it remains and unsolved mystery of our universe. In this work we examine a type II two-Higgs-doublet model extended by a complex singlet (2HDMS), where the pseudo-scalar component of the singlet acts as a natural DM candidate. The DM candidate is stabilized by a Z'2 symmetry, which is broken spontaneously by the singlet acquiring a vacuum expectation value (vev). This vev in turn causes the scalar component of the singlet to mix with the scalar components of the two doublets, which results in three scalar Higgs particles. Additionally we aim to include an excess around 95 GeV, which was observed at CSM and LEP and can be explained by one of the three scalar Higgs particles. After introducing the model, we apply experimental and theoretical constraints and find a viable benchmark point. We then look into the DM phenomenology as well as collider phenomenology.