Improved Measurement of CP Violation in Neutral B Decays to c cbar s

Abstract

We present updated measurements of time-dependent CP asymmetries in fully-reconstructed neutral B decays to several CP eigenstates containing a charmonium meson. The measurements use a data sample of (383 +/- 4) x 10^6 Y(4S)-> BBbar decays collected with the BABAR detector at the PEP-II B factory. We determine sin2beta = 0.714 +/- 0.032 (stat) +/- 0.018 (syst) and |lambda| = 0.952 +/- 0.022 (stat) +/- 0.017 (syst).

7 pages, 2 postscript figures. Final version published on Phys. Rev. Lett. The table with detailed systematic uncertainties is now included separately in EPAPS due to space constraints