Lepton-flavor mixing and K→πνν-bar decays

The impact of possible sources of lepton-flavor mixing on K→πνν-bar decays is analysed. At the one-loop level lepton-flavor mixing originated from non-diagonal lepton mass matrices cannot generate a CP-conserving KL→π0νν-bar amplitude. The rates of these modes are sensitive to leptonic flavor violation when there are at least two different leptonic mixing matrices. New interactions that violate both quark and lepton universalities could enhance the CP-conserving component of Γ(KL→π0νν-bar) and have a substantial impact. Explicit examples of these effects in the context of supersymmetric models, with and without R-parity conservation, are discussed