An SU(15) approach to bifermion classification

Abstract

One interesting way to extend the Standard Model is the hypothesis of bifermions which are bosons that couple to pairs of quarks and leptons. We point out that [Formula: see text] grand unification gives a natural way to classify bifermions and discuss leptoquarks, biquarks and bileptons. In fact, [Formula: see text] provides an ideal covering group as it contains all possible bifermions within a single model.