FLAVOR DEMOCRACY AND QUARK MASS MATRICES

Based on experimental mass hierarchy, a set of flavor–democratic (FD) quark mass matrices at low energies is discussed. The model predicts CP violation parameters JCP = (0.3 ± 0.2) 10 −4 and " ′ /" = (0.6 ± 0.5) 10 −3 . However, this simple FD model also predicts a physical top quark mass not much higher than 100 GeV. As a next step, we assume that the Standard Model (SM) breaks down around some high energy �, and is replaced by a new FD flavor gauge theory (FGT). This possibility can be investigated by studying renormalization group equations for the Yukawa couplings of SM with two Higgs doublets for various mt and v U /v D . With appropriate flavor–democratic boundary conditions at �FGT, bounds on masses of top quark and tau-neutrino are derived, which are compatible with experimental bounds.