Probing SUSY-induced CP violations at B factories

In the minimal supersymmetric standard model (MSSM), there may be new CP violating phases in the $\mu-$parameter and the trilinear coupling $A_t$, as in the scenario of electroweak baryogenesis scenario, for example. Then there may be some deviations from the standard model predictions in the direct CP asymmetry in $B\to X_s \gamma$, $B\to X_s l^+ l^-$ and $B^0 - \bar{B^0}$ mixing. Scanning over the MSSM parameter space with experimental constraints, we find (i) the direct CP violation in $B\to X_s \gamma$ can be as large as $\sim \pm 10 %$ but is very small (less than $\sim 2%$) in the most part of parameter space, (ii) the branching ratio for $B \to X_s l^+ l^-$ can be affected up to $\sim 80%$ compared with the standard model, and (iii) there is no new large phase shift in the $B^0 - \bar{B^0}$ mixing, resulting in the vanishingly small CP violating dilepton asymmetry.