Observation of Direct CP Violation in B{sup 0} --> K{sup +}pi{sup -} Decays

Technical Report · Mon Aug 02 00:00:00 EDT 2004

DOI:https://doi.org/10.2172/829730· OSTI ID:829730

Aubert, B ^[1]

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1. SLAC

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.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (US)
• Sponsoring Organization: USDOE Office of Science (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 829730
• Report Number(s): SLAC-PUB-10582
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
DECAY
MESONS