Flavor-conserving CP phases in supersymmetry and implications for exclusive B decays - art. no. 034020

We study rare exclusive B decays based on the quark-level transition b-->s( d)l(+)l(-), where l = e or u, in the context of supersymmetric theories wit h minimal flavor violation. We present analytic expressions for various mix ing matrices in the presence of new CP-violating phases, and examine their impact on observables involving B and (B) over bar decays. An estimate is o btained for CP-violating asymmetries in (B) over bar-->K(*)l(+)l(-) and (B) over bar -->rho(pi)l(+)l(-) decays for the dilepton invariant mass region 1.2 GeV<Ml+l-<M-J/psi. As a typical result, we find a CP-violating partial width asymmetry of about -6% (-5%) in the case of B-->pi (B-->rho) in effec tive supersymmetry with phases of O(1), taking into account the measurement of the inclusive b-->s gamma branching fraction. On the other hand, CP asy mmetries of less than 1% are predicted in the case of B-->K-(*()). We argue that it is not sufficient to have additional CP phases of O(1) to observe large CP-violating effects in exclusive b-->s(d)l(+)l(-) decays.