The E 6 ⊗ SO(10) preon model based on global SU(18) color-flavor

Abstract

We have constructed a version of the chiral three-preon model E 6 ⊗ SO(10) based on the global color-flavor symmetry group SU(18). By applying the 't Hooft anomaly matching condition to the subgroup SU(16)×SU(2) of SU(18) together with a few physical constraints, we obtain a unique solution that gives rise to three generations of the spinorial representation 16 of SO(10) without exotics. Except for N = 18, no solution at all exists for the global color-flavor group SU( N) (16 < N < 22) when SU( N) breaks to SU(16)×SU( N−16).