GAUGE FIELD THEORY OF HORIZONTAL SU(2) × U(1) SYMMETRY — DOUBLET PLUS SINGLET SCHEME

Gauge field theory of a horizontal symmetry of the group G_H = SU(2)_H × U(1) is developed so as to generalize the standard model of particle physics. All fermion and scalar fields are assumed to belong to doublets and singlets of the group in high energy regime. Mass matrices with four texture zeros of Dirac and Majorana types are systematically derived. In addition to seven scalar particles, the theory predicts existence of one peculiar vector particle which seems to play important roles in astrophysics and particle physics.