Adding a horizontal gauge symmetry to the Weinberg-Salam model: An eight-quark model

An eight-quark model is constructed. It incorporates a horizontal SU(2) gauge symmetry in addition to the SU(2)L×U(1) gauge symmetry of Weinberg and Salam. Cabibbo universality is reproduced. CP violation can also be obtained. Experimental data on the KL-KS mass difference and neutral-current experiments are used to estimate the lower bounds on the masses of the horizontal SU(2) gauge bosons; the values turn out to be less than α^-1/2MW. No mixing exists between the horizontal gauge fields and the SU(2)L×U(1) gauge fields; the Weinberg-Salam model of weak and electromagnetic interactions is preserved perfectly.