Gauge bosons in an SU(2)right x SU(2)left x G(leptonique) electroweak model

Abstract

By considering its generalization to composite J=0 mesons proposed in a previous work [1], I show how and why a chiral extension of the Glashow-Salam-Weinberg standard model of electroweak interactions calls, there, for right-handed charged W_R's coupled with g_R = e/cos(theta_W), and the masses of which are related to the ones of the left-handed W_L's through the relation M_L^2 + M_R^2 = M_Z^2. The mesonic sector, having vanishing baryonic and leptonic number, is neutral with respect to the corresponding U(1) symmetries, making the natural chiral gauge group to be [SU(2)left x SU(2)right], blind to the presence of extra Z's. The W_R gauge bosons cannot have been detected in hadronic colliders and can be very elusive in electroweak processes involving, in particular, pseudoscalar mesons. Present data select one among two possible extensions for which, in the right sector: - a specific breaking of universality occurs between families of quarks, which belong to inequivalent representations of SU(2)right; - the mixing angle is a free parameter, constrained to be smaller than the Cabibbo angle by the box diagrams controlling the K_L-K_S mass difference; this also minimizes contributions to muon -> electron + photon. The relation g_L^2/M_L^2 = g_R^2/M_R^2 implements left-right symmetry for low energy charged effective weak interactions. For the sake of simplicity, this study is performed for two generations only.