Effect of supergravity unification on weak interaction coupling parameters

The one loop supersymmetric contributions to the rho-parameter, the effective Weinberg angle and the μ-decay rate are discussed in a class of supergravity unified models. In the absence of a heavy top quark the corrections to the rho-parameter are very small, while the corrections to sin2Theta/sup eff//sub w/ and the μ-decay rate can be of considerable size. The dependence of these contributions on the parameters of the model (gravitino and gaugino masses) is presented. The presence of a heavy top quark results in large supersymmetric corrections to rho, sin2Theta/sup eff//sub w/ as well as the μ-decay rate