Measurement of CP violating asymmetries in $B^0$ decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23 million Upsilon(4S)-->B-anti-B decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events where one neutral B meson is fully reconstructed in a CP eigenstate 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 sin2beta, is derived from the decay time distributions in such events. The result is sin2beta=0.34 +/- 0.20 (stat) +/- 0.05 (syst).

Note:

9 pages, 2 postscript figures, accepted for publication in Physical Review Letters Report-no: BABAR-PUB-01/01, SLAC-PUB-8777

electron positron: colliding beams
electron positron: annihilation
Upsilon(10570): electroproduction
B0: pair production
B0: hadronic decay
psi mesons: leptonic decay
psi(3685): hadronic decay
K0: hadronic decay
CKM matrix: unitarity
CP: violation

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