Rare kaon decays

The results of recent experiments have shed new light on rare kaon decay. Lepton flavor violation (LFV) experiments have been pushed to remarkable sensitivities, corresponding to mass scales of well over 100 TeV. But this success has killed most models predicting LFV in kaon decay. The recent precision measurement of KL → μ+μ- will be very useful if theorists can nail down the size of the dispersive long-distance amplitude. The author reviews and discusses also recent experimental data on K+ → π+νν-bar and KL → π0νν-bar. The motivation for pursuing K → πνν-bar is stronger than ever. An alternative unitary triangle can be constructed from this data and it will be invaluable for comparison with results from the B system if new physics is at work in the flavor system. (A.C.)