SU(3)(L)CIRCLE-TIMES-U(1)(N) AND SU(4)(L)CIRCLE-TIMES-U(1)(N) GAUGE-MODELS WITH RIGHT-HANDED NEUTRINOS

Pisano and Pleitez have introduced an interesting SU(3)c X SU(3)L X U(1)N gauge model which has the property that gauge anomaly cancellation requires the number of generations to be a multiple of 3. We consider generalizing that model to incorporate right-handed neutrinos. We find that there exists a nontrivial generalization of the Pisano-Pleitez model with right-handed neutrinos which is actually simpler than the original model in that symmetry breaking can be achieved with just three SU(3)L triplets [rather than three SU(3)L triplets and a sextet]. We also consider a gauge model based on SU(3)c X SU(4)L X U(1)N symmetry. Both of these new models also have the feature that the anomalies cancel only when the number of generations is divisible by 3.