Generic consequences of a supersymmetric U(1) gauge factor at the TeV scale

We consider an arbitrary supersymmetric U(1) gauge factor at the TeV scale, under which the two Higgs superfields H-1,H-2 of the standard model are nontrivial. We assume that there is a singlet superfield S such that H1H2S is an allowed term in the superpotential. We discuss first the generic consequences of this hypothesis on the structure of the two-doubler Higgs sector at the electroweak energy scale, as well as Z-Z' mixing and the neutralino sector. We then assume the existence of a grand unified symmetry and universal soft supersymmetry-breaking terms at that scale. We further assume that the additional U(1) is broken radiatively via a superpotential term of the form hh(c)S, where h and h(c) are exotic color-tripler fields which appear in E-6 models. We show that the U(1)-breaking scale and the parameter tan beta=upsilon(2)/upsilon(1) are then both predicted as functions of the H1H2S coupling. [S0556-2821(97)06323-6].