Gluino-squark contributions to CP violations in the kaon system

Abstract

Recently it was shown, within the mass insertion approximation (MIA), that the gluino mediated flavor changing neutral current (FCNC) interactions can saturate both epsilon_K and Re(epsilon'/epsilon_K) even for the real Cabibbo-Kobayashi-Maskawa (CKM) matrix through a single CP violating parameter (delta^d_12)_LL. In this work, we extend our previous analysis to the nonvanishing KM phase, and to the effective SUSY model where the MIA is no longer a good approximation. In our model, epsilon_K and B0 - B0 bar mixing can receive significant SUSY contributions. Therefore the usual constraints on rho and eta in the Wolfenstein parametrization of the CKM matrix can be relaxed except for the |V_ub/V_cb| from the semileptonic b -> u transition. This affects K -> pi nu nu bar and K_L -> mu+ mu- indirectly, even if they are not directly induced by gluino-mediated FCNC, while K_L -> pi0 e+ e- is influenced both directly and indirectly. Differences between our model and other SUSY models enhancing Re(epsilon'/epsilon_K) are discussed in detail.

Comments: 29 pages, 6 figures, 1 table; typos and references corrected; version to appear in NPB