Lepton-flavor mixing and K → πνν̄ decays

The impact of possible sources of lepton-flavor mixing onK → πνν̄ decays is analysed. At the one-loop level lepton-flavor mixing originated from non-diagonal lepton mass matrices cannot generate a CP-conserving KL → πνν̄ 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 → πνν̄) and have a substantial impact. Explicit examples of these effects in the context of supersymmetric models, with and without R-parity conservation, are discussed. On leave of absence from Department of Physics, University of California, Berkeley, CA 94720, USA Permanent address