Speaker: Duarte Azevedo
Two of the simplest models of dark matter (DM), in the context of scalar extensions of the Standard Model (SM), will be presented. A scalar DM and a vector DM model. These models require two physical Higgs bosons, h1 and h2, which arise from mixed components of the SM doublet and an additional complex singlet S. In the scalar case, we impose a dark charge symmetry Z2 (S→S*) which forces stability on the imaginary component of the singlet (A→-A), the dark matter candidate. We also demand explicit breaking, albeit softly, of the U(1) symmetry for a massive DM. In the vector case, an additional U(1) symmetry is broken by the vacuum of the singlet. This leads to a massive gauge boson Xmu which is stable because of an analogous dark charge conjugation symmetry (S→S*, Xmu → -Xmu) and, thus, a DM candidate.