Chiral Lagrangians and Kaon CP-Violation

Abstract

These lectures are an introduction to the subject of chiral effective Lagrangians of the Standard Model and their applications, mostly in the sector of non--leptonic kaon decays, with special emphasis on CP--violation. The first lecture gives an introduction to the phenomenological description of the $K^0-\bar{K}^0$ system and $K\ra ππ$ decays. In the second lecture I give an overview of the basic ideas behind the chiral perturbation theory ($χ$PT) --approach to hadron dynamics at low energies. The study of the weak interactions of $K$--particles within the framework of $χ$PT is the subject of the third lecture. The fourth lecture is an overview of various models of the QCD low--energy effective action which have been developed during the last few years. The fifth lecture is dedicated to a discussion of the CP--violation $ε$ and $ε'$ parameters, and to the study of the decay mode: $K_{L}\ra π^{0}e^{+}e^{-}$.