ABSTRACT
This chapter considers several other possible elaborations of the minimal two-doublet extension of the Standard Model, focusing exclusively on those that have the strongest aesthetic and theoretical motivations. The phenomenology of these Higgs bosons has close similarities to that of the Higgs sector in the minimal supersymmetric model. In addition, even though the generally expected Higgs boson masses are fairly modest, the most useful production cross sections are often not as large as in the corresponding Standard Model Higgs boson case. The renormalization group equations that control group evolution imply that a large Yukawa coupling to fermions is required to generate such a negative mass squared in the Higgs potential. The quark-antiquark coupling of a neutral Higgs boson to a heavy quark determines one of its most important production processes at a hadron collider, namely gluon-gluon fusion to Higgs via a heavy quark triangle graph.
