What we have learned from direct CP violation studies in kaon decays

Abstract

A self-consistent analysis of K --> 2pi and K --> 3pi decays within a unique framework of chiral dynamics applied to the QCD-corrected weak nonleptonic quark lagrangian has been performed. The results on K --> 2pi amplitudes at O(p^6), including the value for epsilon'/epsilon, are compared with experiment to fix phenomenological B-factors for mesonic matrix elements of nonpenguin and penguin four-quark operators. The dependence of these B-factors on different theoretical uncertainties and experimental errors of various input parameters is investigated. Finally, we present our estimates at O(p^6) for the CP asymmetry of linear slope parameters in the K+- --> 3pi Dalitz plot.