Study of Time-Dependent CP Violation in B0-->J/psipi0 Decays
S. U. Kataoka, K. Abe, I. Adachi, H. Aihara, M. Akatsu, Y. Asano, T. Aushev, S. Bahinipati, A. M. Bakich, A. Bay, I. Bedny, U. Bitenchttp://academic.research.microsoft.com/io.ashx?type=5&id=12569504&selfId1=0&selfId2=0&maxNumber=12&query=
We report a measurement of CP asymmetry parameters in the decay B0(B¯0)-->J/psipi0, which is governed by the b-->cc¯d transition. The analysis is based on a 140 fb-1 data sample accumulated at the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric-energy e+e- collider. One neutral B meson in the J/psipi0 final state is fully reconstructed for events used in this analysis. The accompanying B meson flavor is identified by its decay products. From the distribution of proper-time intervals between the two B decays, we obtain the following CP-violating parameters: SJ/psipi0=-0.72±0.42(stat)±0.09(syst) and AJ/psipi0=-0.01±0.29(stat)±0.03(syst).