Rare kaon decays

Major advances spanning several orders of magnitude in sensitivity are anticipated in the current round of experiments with rare kaon decays. Observations of allowed processes, like Κ+ → π+ νν-bar and Κ0L → μ+μ-, shed light on detailed aspects of the standard model. New sources of T or CP violation could be manifested by measurements of muon polarization in Κ → δμνμ and Κ0L → μ+μ- decays and by studies of reactions like Κ0L → π0e+e-. Evidence for new particlews and new interactions could appear in advanced efforts to observe Κ → πchichi' and Κ → πchi decays, where chi and chi' represent hypothethetical neutral particles, and in searches for lepton flavor violating processes Κ0L → μe and Κ+ → π+ μe. The experiments are reviewed and their theoretical context is discussed