Improved measurement of CP-violation parameters sin 2φ 1 and

Abstract

We present a precise measurement of the standard model CP-violation parameter sin2φ 1, the direct CP violation parameter |λ|, the lifetimes of charged and neutral B mesons and their ratio, and the B 0-B̄ 0 mixing parameter Δm d based on a sample of 152 x 10 6 BB̄ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e +e - collider. One of two B mesons is fully reconstructed in a CP-eigenstate or a flavor-eigenstate decay channel. The flavor of the accompanying B meson is identified from its decay products. From the distributions of the time interval between the two B meson decay points, we obtain sin2φ 1 = 0.728 ± 0.056(stat) ± 0.023(syst), |λ| = 1.007..