Analysis of horizontal symmetries in a minimal SU(2)sub(L)XSU(2)sub(R)XU(1) gauge theory

A left-right symmetric gauge theory of electroweak interactions is considered in which only one Higgs field and its charge conjugate couple to quarks. Among all possible parity transformations those allowing for phenomenologically acceptable mass matrices are singled out. In such a theory arbitrary horizontal symmetry groups with unitary representations are investigated. Both for two and three quark generations essentially only one model emerges which is compatible with empirical constraints on quark masses and mixing angles. (Auth.)