PredictiveAnsatzfor fermion mass matrices in supersymmetric grand unified theories

In this paper we present a new Ansatz for fermion mass matrices in the context of supersymmetric grand unified theories. We are able to fit the 13 parameters, associated with quark and lepton masses and mixing angles, and the ratio of Higgs vacuum expectation values (VEV's) which enters any supersymmetric theory, in terms of 8 input parameters; hence, we have 6 predictions. The top quark is predicted to have a mass in the range 176 to 190 GeV, where the upper bound results from the assumption of perturbative unification, and the lower bound is sensitive to the experimental value of $V_{\mathrm{cb}}$. Predictions are also made for $m_s$, $\frac{m_s}{m_d}$, $\left|\frac{V_{\mathrm{ub}}}{V_{\mathrm{cb}}}\right|$, the ratio of Higgs VEV's, and the $\mathrm{CP}$-violating phase of the Kobayashi-Maskawa matrix.