Theory Status of eps'/eps

TL;DR

This paper reviews the current theoretical understanding of epsilon'/epsilon in kaon decays, emphasizing the importance of higher order corrections and non-factorizable effects, and discusses future prospects with lattice QCD.

Contribution

It provides a comprehensive overview of the theoretical status of epsilon'/epsilon, highlighting the role of various corrections and the need for improved lattice calculations.

Findings

Higher order chiral corrections are significant.

Non-factorizable contributions impact CP violation explanations.

Progress in lattice QCD is anticipated in the near future.

Abstract

I shortly review the present status of the theoretical calculations of eps'/eps and the comparison with 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 and direct CP violation in kaon decays. Still lacking satisfactory lattice calculations, analytic methods and phenomenological approaches are helpful in understanding correlations among theoretical effects and experimental data. Substantial progress from lattice QCD is expected in the coming years.