Connection between generation number and anomaly cancellation in supersymmetric models

Abstract

We construct supersymmetric theories in which the number of generations of quarks and leptons is related by gauge anomaly cancellation to the spectrum of Higgs fields. Models yielding at least three generations with the minimal Higgs spectrum assumed are discussed in detail. This mechanism requires an extension of the standard model gauge group such that an ordinary quark-lepton generation is not anomaly-free. We discuss models of SU (3) weak isospin, separate isospin groups for quarks and leptons, and chiral colour. © 1989.