Download or read book An Observation of Direct-CP Violation -????????? Result 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: We 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. Other new measurements of?m,?{sub s},?? and a limit on the diurnal variation of?{sub +-} for testing CPT invariance from the same data sample are also presented.