(S) QUARK MASSES AND NON-ABELIAN HORIZONTAL SYMMETRIES

We present a model of quark and squark masses which is based on a non-Abelian horizontal symmetry. It leads to order of magnitude relations between quark mass ratios and mixing angles and to the successful exact relations in theta(C) = square-root m(d)/m(s) to better than 20% accuracy. The non-Abelian symmetry also ensures the necessary squark degeneracy to suppress FCNC mediated by loops with squarks and gluinos, in the neutral meson systems.