CP violation in SUSY left-right models

Abstract

We analyze the minimal supersymmetric left-right model with non-renormalizable interactions induced by higher scale physics and study its CP violating properties. We show that it: (i) solves the strong CP problem; (ii) predicts the neutron electric dipole moment well within experimental limits (thus solving the usual SUSY CP problem). In addition, it automatically conserves R -parity. The key points are that the parity symmetry forces the Yukawa couplings to be hermitean, while supersymmetry ensures that the scalar potential has a minimum with real higgs doublet vacuum expectation values. Gluino and B-L gaugino masses are automatically real. The observed CP violation in the kaon system comes, as in the Standard Model, from the Kobayashi-Maskawa-type phases. These solutions are valid for any value of the right-handed breaking scale M R , as long as the effective theory below M R has only two Higgs doublets that couple fully to fermions. (i.e. the theory below M R is MSSMlike.) The potentially dangerous contributions from the SU (2) L gaugino one-loop diagram as well as from some higher dimensional terms to φ¯ below M R can be avoided if the left-right symmetry originates from a unified theory such as SO(10) and we discuss how this embedding is achieved for the SO(10) case.