Low-energy lepton violation from supersymmetric flipped SU(5)

We construct a supersymmetric flipped SU(5){}U(1) model which violates R parity and electron number at low energies, through a superpotential term 1/2CⁱʲᵏLᵢLⱼEₖᶜ. Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the Cⁱʲᵏ coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting Z⁰ decays are predicted: e.g., Z⁰→e^-μ⁺e⁺μ^- with invariant mass peaks in the (e, μ) channels.