Quark and Lepton Mass Matrix in an Asymptotically Non-Free Theory

We analyze fermion mass-matrix structure in an asymptotically non-free model with 4 + 1^^- generations. The texture at the GUT scale is uniquely determined by supposing that the masses of heavy up-type quarks (charm as well as top) are realized as their infrared fixed point values. By assuming SO(10) GUT-like relations for Yukawa couplings in this model, this texture can explain all fermion masses and quark mixing with only one small parameter, which is almost equal to the Cabibbo angle