UNIFIED ELECTRO-WEAK MODEL IN SU(3)

In this paper a unified electro-weak model for leptons based on the SU(3) gauge group is suggested by means of four kinds of realization for the generators of the group. For all low energy electro-weak processes, this model predicts the same results as the conventional Weinberg-Salam model does. The Weinberg angle is shown to be sin³θ_w = ¼ in a natural way. When the Higgs self potential respects a discrete symmetry Φ → − Φ, a new conserved quantum number called weak strangeness emerges from the model after spontaneous symmetry breaking. In the present model there exist another four heavy vector gauge bosons V^± and U^±± together with some heavy fermions and Higgs scalars, which have non vanishing weak strangeness quantum numbers. These weak strange particles have no direct couplings with leptons. Their existence will not influence the low energy electro-weak processes. Nevertheless, they can be produced in pairs in high energy collisions and the lightest of them should be stable if the conservation of weak strangeness is exact. The experimental implications and the possibility of violation of the conservation of weak strangeness are also discussed.