Assignment of lepton numbers in supersymmetry

Abstract
In a supersymmetric extension of the standard SU(3) × SU(2) × U(1) gauge model of fundamental interactions, the assignment of lepton numbers to the color-singlet fermions is not unique. In addition to the conventional assignment, there are five other generically distinct scenarios, each with three possible variations. The existing experimental data constrain the values of various new couplings present in these models.