Measurement of the branching fraction and time-dependent CP asymmetry for B-0 -˃ J/psi pi(0) decays

Abstract

We measure the branching fraction and time-dependent CP-violating asymmetry for B-0 -> /psi pi(0) decays using a data sample of 711 fb(-1) collected on the Gamma(4S) resonance by the Belle experiment running at the KEKB e(+)e(-) collider. The branching fraction is measured to be B(B-0 -> /psi pi(0)) = [1.62 +/- 0.11(stat) +/- 0.06(syst)] x 10(-5), which is the most precise measurement to date. The measured CP asymmetry parameters are S = -0.59 +/- 0.19(stat) +/- 0.03 (syst) and A = 0.15 +/- 0.14(stat)(-0.03)(+0.04) (syst). The mixing-induced CP asymmetry (8) differs from the case of no CP V i lotion by 3.0 standard deviations, and the direct CP asymmetry (A) is consistent with zero.