Re({epsilon}{prime}/{epsilon})Result from KTeV - An observation of direct-CP violation

Abstract

Using a subset of data collected in the 1996-97 fixed target run at Fermilab, the authors report the first preliminary measurement on the direct-CP violation from the KTeV experiment. The result is, e{prime}/e = (28.0-4.1) x 10{sup {minus}4}, nearly 7 standard deviations above zero obtained by a blind analysis. This establishes the long-sought direct-CP violation effect in the two-pion system of neutral kaon decays. The experimental technique, data analysis and systematic checks for this measurement are discussed and the comparison with other measurements is also presented