Theory of eps'/eps

Abstract

I shortly review the present status of the theoretical estimates of eps'/eps. I consider a few aspects of the theoretical calculations which may be relevant in understanding the present experimental results. I discuss the role of higher order chiral corrections and in general of non-factorizable contributions for the explanation of the Delta I = 1/2 selection rule in kaon decays and eps'/eps. Lacking reliable lattice calculations, the 1/N expansion and phenomenological approaches may help in understanding correlations among theoretical effects and the experimental data. The same dynamics which underlies the CP conserving selection rule appears to drive eps'/eps in the range of the recent experimental measurements.