Measurement of the CP violation parameter sin2φ1 in Bd0 meson decays

We present a measurement of the standard model CP violation parameter sin2 phi (1) (also known as sin2 beta) based on a 10.5 fb(-1) data sample collected at the Y (4S) resonance with the Belie detector at the KEKB asymmetric e(+)e(-) collider. One neutral B meson is reconstructed in the J/psi K (S), psi (2S)K (S), chi K-c1 (S), eta K-c (s), J/psi K (L), or J/psi pi (0) CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay paints, we determine sin2 phi (1) = 0.58(-0.34)(+0.32)(stat)(+0.09)(-0.10)(syst).