Updated Constraints on the Higgs Singlet Extension of the SM

Abstract: We discuss the current status of theoretical and experimental constraints on the real Higgs singlet extension of the Standard Model. For the second neutral (non-standard) Higgs boson we consider the full mass range from 30 GeV to 1 TeV, which is accessable to past and present collider experiments. We investigate the impact of constraints from perturbative unitarity, higher order contributions to the W boson mass, perturbativity of the couplings as well as vacuum stability, as well as direct collider constraints and the Higgs signal rate measurements. We comment on the collider phenomenology of the remaining viable parameter space and the prospects for a future discovery or exclusion at the LHC.