Estimating epsilon'/epsilon in the Standard Model

Abstract

I discuss the comparison of the current theoretical calculations of epsilon'/epsilon with the experimental data. Lacking reliable ``first principle'' calculations, phenomenological approaches may help in understanding correlations among different contributions and available experimental data. In particular, in the chiral quark model approach the same dynamics which underlies the Delta I = 1/2 selection rule in kaon decays appears to enhance the K -> pi pi matrix element of the Q_6 gluonic penguin, thus driving epsilon'/epsilon in the range of the recent experimental measurements.