Horizontal Gauge Symmetry and Masses of Neutrinos

Recently several authors have studied a possible unification of electronic and muonic matter by adding the horizontal local-symmetry, SU_F(2),^1)~3) to the weak and electromagnetic SU(2) ×U(1).⁴⁾ As a consequence of gauging the symmetry, the conservation of muon number is violated. The exchange of horizontal gauge bosons, , also induce the superweak type of CP-nonconservation.¹⁾ From the data on CP-violation in decay, the effective coupling constant, G_S, of with leptons and quarks is determined as G_S ~ 10⁻¹⁵ GeV⁻² unless the accidental cancellation occurs.¹⁾ The strength is enough weak to avoid unwanted flavour-changing transitions.