Superweak CP violation and right-handed horizontal interactions

Abstract

A horizontal extension of the Weinberg-Salam electroweak theory by a right-handed O(3)_RH gauge symmetry for the three-fermion families is studied. By an appropriate choice of the Higgs scalar fields the CP symmetry of the lagrangian is spontaneously broken, but the mixing of the left-handed fermion states, and hence the Kobayashi-Maskawa mixing matrix, remains real. The CP violation is manifested in the superweak horizontal gauge interactions, which are suppressed by the large mass of the corresponding gauge bosons. It is, however, possible that the horizontal boson acting on the second and third families can be considerably lighter than the two,s implying an interesting phenomenology of the related CP violation effects and flavour-changing neutral currents.