Observation of CP Violation in the B{sup 0} Meson System

Journal Article · Mon Aug 27 00:00:00 EDT 2001 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.87.091801· OSTI ID:40277441

Aubert, B; Boutigny, D; Gaillard, J -M; Hicheur, A; Karyotakis, Y; Lees, J P; Robbe, P; Tisserand, V; Palano, A; Chen, G P ^[1]

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1. and others

We present an updated measurement of time-dependent CP -violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of {Upsilon}(4S) decays collected in 2001, bringing the data available to 32 x 10{sup 6} B{bar B} pairs. We select events in which one neutral B meson is fully reconstructed in a final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP -violating asymmetry, which in the standard model is proportional to sin<hspace SPACE=''-0.167''>2{beta} , is derived from the decay time distributions in such events. The result sin<hspace SPACE=''-0.167''>2{beta}=0.59{+-}0.14( stat){+-}0.05(syst) establishes CP violation in the B{sup 0} meson system. We also determine |{lambda}|=0.93{+-}0.09(stat) {+-}0.03(syst) , consistent with no direct CP violation.

• Sponsoring Organization: (US)
• OSTI ID: 40277441
• Journal Information: Physical Review Letters, Vol. 87, Issue 9; Other Information: DOI: 10.1103/PhysRevLett.87.091801; Othernumber: PRLTAO000087000009091801000001; 028136PRL; PBD: 27 Aug 2001; ISSN 0031-9007
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ASYMMETRY
B MESONS
CHARMONIUM
DAUGHTER PRODUCTS
DECAY
MESONS
STANDARD MODEL