Squark Mixing Contributions to CP violating phase gamma

We investigate the possibility that the CP violation due to the soft supersymmetry breaking terms in squark mixing can give significant contributions to the various $\gamma$ related parameters in B decays, different from those of the Standard Model. We derive the new limits on $(\delta^u_{12})_{LL,LR,RR}$ and on $(\delta^d_{23})_{LL,LR,RR}$ from the recent data on $D^0$--$\bar{D}^0$ oscillation as well as those on $B_s^0$--$\bar{B_s}^0$ oscillation. We show that, together with all the other constraints, the currents limits on these parameters still allow large contributions to the CP violating phases in $B_s^0$--$\bar{B_s}^0$ as well as $D^0$--$\bar{D}^0$ oscillations which will modify some of the proposed measurements of $\gamma$ parameters in CP violating B decays. However, the current constraints already dictate that the one-loop squark mixing contributions to various B decay amplitudes cannot be competitive with that of the Standard Model (SM), at least for those B decay modes which are dominated the tree level amplitudes within the SM, and therefore they are not significant in contributing to CP asymmetries in the corresponding B decays.