Horizontal gauge interaction as the primary source of CP violation.

Abstract

A model, in which the Kobayashi-Maskawa matrix is real and CP violation is mediated by a horizontal gauge interaction, is presented. Right-handed fermions are in triplet representations of an SU(2) horizontal group. The CP-violation parameter epsilon and K/sub L/-K/sub S/ mass difference are used to give a lower bound on the only (dominant) CP-violating phase, and also a bound on the horizontal gauge-boson mass (M/sub s//sub c//sub r//sub R/) range such that 66 TeVgreater than or equal to(g/sub L//g/sub R/)M/sub scrR/greater than or equal to5 TeV. epsilon' is found to be extremely small. Contributions to the theta parameter vanish at the tree and one-loop levels. It has an interesting value at the two-loop level. The branching ratio of K/sub L/..--> mu..e is predicted to be greater than 10/sup -10/ in the simplest version of the model. With present assumptions, the model does not permit CP violation to be observable in the B-meson systems, although rare lepton-number-nonconserving semileptonic B decays show interesting rates. The detection possibilities of the new gauge bosons at the Superconducting Super Collider are also explored. Directions for variations and extensions of the model are discussed.