Solving the supersymmetric CP problem with Abelian horizontal symmetries Original Research Article

Models that combine Abelian horizontal symmetries and spontaneous CP violation can (i) explain the smallness and hierarchy in quark parameters; (ii) satisfactorily suppress supersymmetric contributions to flavor changing neutral current processes; (iii) solve the μ-problem; and (iv) suppress supersymmetric contributions to CP violating observables to an acceptable level. The CKM phase is O(1) and responsible, through Standard Model box diagrams, to ϵK. The supersymmetric CP violating phases are suppressed, φA ∼ λ6 and φB ∼ λ8 (λ ∼ 0.2), leading to an electric dipole moment of neutron that is about 2–3 orders of magnitude below the experimental bound.