Precise measurement of the CP violation parameter sin2phi_1 in   B0-->(c\bar c)K0 decays
  We present a precise measurement of the CP violation parameter sin2phi_1 and the direct CP violation parameter A_f using the final data sample of 772x10^6 B\bar B pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. One neutral B meson is reconstructed in a J/psi K0S, psi(2S) K0S, chi_c1 K0S or J/psi K0L CP-eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper time intervals between the two B decays, we obtain the following CP violation parameters: sin2phi_1=0.667+-0.023(stat)+-0.012(syst) and A_f=0.006+-0.016(stat)+-0.012(syst). 
Belle Collaboration: I.Adachi, H.Aihara, D.M.Asner, V.Aulchenko,   T.Aushev, T.Aziz, A.M.Bakich, A.Bay, V.Bhardwaj, B.Bhuyan...
hep-ex