Evidence for CP Violation in B^{0}→J/ψπ^{0} Decays

We present measurements of the branching fraction and time-dependent CP asymmetries in B-0 -> J/psi pi(0) decays based on 466x10(6) Gamma(4S)-> B (B) over bar events collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We measure the CP asymmetry parameters S=-1.23 +/- 0.21(stat) +/- 0.04(syst) and C=-0.20 +/- 0.19(stat)+/- 0.03(syst), where the measured value of (S, C) is 4.0 standard deviations from (0, 0) including systematic uncertainties. The branching fraction is determined to be B(B-0 -> J/psi pi(0))=[1.69 +/- 0.14(stat)+/- 0.07(syst)]x10(-5).