2002/03/05 by B. Aubert, BABAR Collaboration, Aubert, B. +1
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Neutrino Physics Research #Particle Detector Development and Performance #Particle physics theoretical and experimental studies #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0203007
14 pages, 4 figures, to be presented at the 16th Rencontres de Physique de la Vallee d'Aoste, La Thuile, Italy
arxiv created 2002/03/05 · openalex publication_date 2002/03/05 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present updated results on time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 62 million Upsilon(4S) --> B anti-B decays collected between 1999 and 2001 by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. In this sample we study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson 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 sin2beta, is derived from the decay time distributions in such events. We measure sin2beta = 0.75 +/- 0.09 (stat) +/- 0.04 (syst) and |λ| = 0.92 +/- 0.06 (stat) +/- 0.02 (syst). The latter is consistent with the Standard Model expectation of no direct CP violation. These results are preliminary.