FLAVOR MIXING SIGNALS FOR REALISTIC SUPERSYMMETRIC UNIFICATION

The gauge interactions of any supersymmetric extension of the standard model involve new flavor mixing matrices. The assumptions involved in the construction of minimal supersymmetric models, both SU(3) x SU(2) xU(1) and grand unified theories, force a large degree of triviality o n these matrices. However, the requirement of realistic quark and lept on masses in supersymmetric grand unified theories forces these matric es to be nontrivial. This leads to important new dominant contribution s to the neutron electric dipole moment and to the decay mode p --> K- 0 mu(+), and suggests that there may be important weak scale radiative corrections to the Yukawa coupling matrix of the up quarks. The lepto n flavor-violating signal mu --> e gamma is studied in these theories when tan beta is sufficiently large that radiative effects of coupling s other than lambda(t) must be included. The naive expectation that la rge tan beta will force sleptons to unacceptably large masses is not b orne out: radiative suppressions to the leptonic flavor mixing angles allow regions where the sleptons are as light as 300 GeV, provided the top Yukawa coupling in the unified theory is near the minimal value c onsistent with m(t).