Theoretical Status of K->pinunubar Decays

Abstract

We present a concise review of the theoretical status of rare K->pinunubar decays in and beyond the standard model. Particular attention is thereby devoted to the recent calculation of the next-to-next-to-leading order corrections to the charm quark contribution of K^+->pi^+nunubar which removes the last relevant theoretical uncertainty from the K->pinunubar system.