Review on epsilon'/epsilon

TL;DR

This paper reviews recent experimental efforts at CERN and Fermilab to measure the CP violation parameter epsilon'/epsilon, confirming the existence of direct CP violation with high statistical significance.

Contribution

It summarizes the latest experimental results and the combined world average, highlighting the confirmed presence of direct CP violation in kaon decays.

Findings

Fermilab KTeV-E832 measured Re(epsilon'/epsilon) = (19.2 ± 2.1) x 10^{-4}

The world average shows direct CP violation with 12 standard deviations

Experimental efforts have converged to confirm CP violation in decay processes

Abstract

Experiments at CERN and Fermilab have been competing each other to improve the measurement of a CP violation parameter, epsilon'/epsilon. Fermilab KTeV-E832 recently announced their final result, Re(epsilon'/epsilon) = [19.2 +- 2.1] x 10^{-4}. The new world average shows the existence of direct CP violation in the decay process itself with 12 standard deviations.