A precise measurement of the direct CP violation parameter Re(epsilon'/epsilon)

TL;DR

This paper reports a precise measurement of the direct CP violation parameter Re(epsilon'/epsilon) in neutral kaon decays, using a large dataset collected by the NA48 experiment at CERN, confirming CP violation effects.

Contribution

It provides a highly accurate measurement of Re(epsilon'/epsilon), improving the precision of CP violation parameters in kaon decays.

Findings

Re(epsilon'/epsilon) = (15.3 +- 2.6) x 10^-4

Large dataset of 3.3 million KL->pi0pi0 events

Confirmation of direct CP violation in neutral kaons

Abstract

The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. With 3.3 million KL->pi0pi0 events collected during the 1998 and 1999 running periods, a result of Re(epsilon'/epsilon) = (15.0 +- 2.7)x10-4 has been obtained. The result combined with the published 1997 sample is Re(epsilon'/epsilon) = (15.3 +- 2.6)x10-4.