Observing the Dark Scalar Doublet and its Impact on the Standard-Model Higgs Boson at Colliders

Abstract

If the Standard Model of particle interactions is extended to include a second scalar doublet $[H^{+},(H^{0}+iA^{0})/\sqrt{2}]$, which is odd under an unbroken Z_{2} discrete symmetry, it may be called the $dark$ scalar doublet, because its lightest neutral member, say H^{0}, is one posssible component for the dark matter of the Universe. We discuss the general phenomenology of the four particles of this doublet, without assuming that H^{0} is the dominant source of dark matter. We also consider the impact of this $dark$ scalar doublet on the phenomenology of the SM Higgs boson h.

PRD version