Probing the Flavor and CP Structure of Supersymmetric Models with K --> pi nu nubar Decays

We study the implications of various supersymmetric models on the rare $K^+ \to \pi^+ \nu \bar\nu$and$K_L \to \pi^0 \nu \bar\nu$ decays. Although large effects are possible in generic supersymmetric models, most of the known supersymmetric flavor models lead to negligible effects. Thus, it is likely that one can get information about CKM matrix elements from these decays even in the presence of supersymmetry. Moreover, the possibility of large contributions to $K\to \pi \nu \bar{\nu }$ in generic supersymmetric models can be constrained by improved bounds on $D-\bar{D}$ mixing. We show that it may be possible to distinguish between different supersymmetric flavor models by combining the information from the $K\to \pi \nu \bar{\nu }$ decays with that from $B-\bar{B}$ and $D-\bar{D}$ mixing.