Improved measurement of CP violation in neutral B decays to cc[over]s

Phys Rev Lett. 2007 Oct 26;99(17):171803. doi: 10.1103/PhysRevLett.99.171803. Epub 2007 Oct 25.

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)x10(6) Upsilon(4S)-->BB[over] 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).