Download or read book Observation of Direct CP Violation in B[sup 0] --] K[sup +]pi[sup -] Decays written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present an updated search for direct CP violation in the decay B[sup 0] --> K[sup +]pi[sup -]. Using 227 million [Upsilon](4S) --> B[bar B] decays collected with the BaBar detector at the PEP-II asymmetric-energy E[sup +]e[sup -] collider at SLAC, the authors observe a total signal yield of n(K-pi[sup +]) + n(K[sup +]pi[sup -]) = 1606 [+-] 51 decays and measure the asymmetry [n(K[sup -]pi[sup +])-n(K[sup +]pi[sup -])]/[n(K[sup -]pi[sup +])+n(K[sup +]pi[sup -])] = 0.133 [+-] 0.030(stat) [+-] 0.009(syst). This measurement establishes direct CP violation in the B[sup 0] meson system at the level of 4.2 standard deviations.