Supersymmetry inspired minimal lepton number violation

A minimal lepton number violation (LNV) is proposed which could naturally appear in SUSY theories, if Yukawa and LNV couplings had a common origin. According to this idea properly implemented into the minimal supersymmetric standard model (MSSM) with an additional Abelian flavor symmetry, a prototype LNV appears due to the mixing of leptons with superheavy Higgs doublet mediating Yukawa couplings. As a result, all significant physical manifestations of LNV reduce to those of the effective trilinear couplings LL (E) over bar and LQ (D) over bar aligned, by size and orientation ina flavor space, with the down fermion (charged lepton and down quark) effective Yukawa couplings, while the effective bilinear terms appear generically suppressed relative to an ordinary mu term of the MSSM. The detailed phenomenology of the model related to the flavor-changing processes both in quark and lepton sectors, radiatively induced neutrino masses, and decays of the LSP, is presented. Remarkably, the model can straightforwardly be extended to a grand unified framework and an explicit example with an SU(7) GUT is thoroughly discussed.