Chiral Lagrangians and Kaon CP-Violation

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 $K\text{ra}\pi \pi$ decays. In the second lecture I give an overview of the basic ideas behind the chiral perturbation theory ($\chi$PT) –approach to hadron dynamics at low energies. The study of the weak interactions of $K$–particles within the framework of $\chi$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 ${ϵ}^{\mathrm{\prime }}$ parameters, and to the study of the decay mode: $K_L\text{ra}{\pi }^0{e}^{+}{e}^{-}$.