Probing Supersymmetry-InducedCPViolation atBFactories

In the minimal supersymmetric standard model, the $\mu$ parameter and the trilinear coupling $A_t$ may be generically complex and can affect various observables at $B$ factories. Imposing the electric dipole moment constraints, we find that there is no new large phase shift in the $B^0-\overline{B^0}$ mixing, $\mathrm{CP}$ violating dilepton asymmetry is smaller than $0.1\%$, and the direct $\mathrm{CP}$ violation in $B\to X_s\gamma$ can be as large as $\sim \pm 16\%$.