Aspects of CP violation in supersymmetric theories

Abstract

We give a comprehensive study of CP-violating effects in low-energy softly broken supersymmetric theories. We find that gluino exchange contributions to CP violation arising from the Kobayashi-Maskawa mixing matrix may provide indirect evidence of supersymmetry at low energy. Indeed, we point out two important departures from the predictions of the standard model: (i) in the kaon system, the experimental value of the ε-parameter cannot be reconciled with a large B-lifetime (τ_B>10⁻¹²s) and light top quark (m_t≲ 50GeV) in the context of the usual three-generation standard model; this is no longer true when the additional supersymmetry contributions to CP violation are included; (ii) in the beon system, the presence of supersymmetry enhances B⁰−B^-0mixing as well as off-shell and on-shell CP-violating phenomena making more likely an experimental detection of some of the effects. On the other hand, the electric dipole moment of the neutron due to the Kobayashi-Maskawa phase is still very small and ε'/ε continues to be consistent with the experimental bounds.