Journal article

Evidence for CP violation in B-0 -> J/psi pi(0) decays

B Aubert, M Bona, Y Karyotakis, JP Lees, V Poireau, E Prencipe, X Prudent, V Tisserand, J Garra Tico, E Grauges, L Lopez, A Palano, M Pappagallo, G Eigen, B Stugu, L Sun, GS Abrams, M Battaglia, DN Brown, J Button-Shafer Show all

PHYSICAL REVIEW LETTERS | AMER PHYSICAL SOC | Published : 2008

Abstract

We present measurements of the branching fraction and time-dependent CP asymmetries in B0-->J/psipi0 decays based on 466 x 10(6) Upsilon(4S)-->BB over 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(B0-->J/psipi0)=[1.69+/-0.14(stat)+/-0.07(syst)]x10(-5).