Download or read book Observation of Direct-CP Violation -????????? from KTeV. written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors report the first KTeV measurement for the search of direct-CP violation by using 23% of the data sample collected in the 1996-97 fixed target run at Fermilab. The result is, Re(????????/?) = (28.0 ± 4.1) x 10−4, nearly 7? above zero obtained by a blind analysis. This firmly establishes the long-sought direct-CP violation effect in the two-pion system (??− versus?°?°) of neutral kaon decays.