SUPERSYMMETRY AND THE SPONTANEOUS BREAKING OF A U(1) GAUGE FACTOR

We investigate a supersymmetric theory with an extra U(1) gauge symmet ry surviving down to low energies. The extra U(1) is assumed to origin ate from an E(6) grand unified theory (GUT). We show that if one assum es universal soft supersymmetry-breaking scalar masses at the GUT scal e, and requires the mass of the additional U(1) gauge boson to satisfy phenomenological bounds, then the conditions for electroweak symmetry breaking will provide stringent restrictions on the allowed parameter space of such a theory. We also determine the masses of standard as w ell as exotic sfermions and find that it is possible for the latter to be lighter than the former. An interesting specific observation is th at a light top squark is difficult to accommodate with an extra U(1) g auge symmetry.