ALPHA(S)(M(Z)), INTERMEDIATE SCALES AND FERMION MASSES IN SUPERSYMMETRIC THEORIES - 2-LOOP RESULTS

One way to generate an intermediate scale being consistent with gauge coupling unification is to add new Higgs scalars above the intermediat e scale. We classify such scenarios according to their degree of depar ture from minimal supersymmetric standard model. Thereafter, we summar ize the results of a two-loop renormalization group analysis of the ga uge and the Yukawa sectors of such scenarios, and their sensitivity to the input alpha(3)(m(Z)). The presence of an adjoint color octet abov e the intermediate scale can raise the gauge coupling unification scal e to the string scale, acommodate a suitable intermediate scale, provi de a left-handed tau-neutrino of mass of the order of few electron vol ts and also have the right prediction of the low energy ratio of m(b)/ m(tau).