We report first observations of B-s(0) -> J/psi eta and B-s(0) -> J/psi eta'. The results are obtained from 121.4 fb(-1) of data collected at the Gamma(5S) resonance with the Belle detector at the KEKB e(+)e(-) collider. We obtain the branching fractions B(B-s(0)-> J/psi eta')=[5.10 +/- 0.50(stat)+/- 0.25(syst)(-0.79)(+1.14)(N-Bs()(B) over bars()] X 10(-4,) B(B-s(0)-> J/psi eta') = [3.71 +/- 0.61(stat)+/-(+0.83)(-0.57)(N-Bs()(B) over bars()] X 10(-4). The ratio of the two branching fractions is measured to be B(B-s -> J/psi eta')/B(B-s -> J/psi eta) = 0.73 +/- 0.14(stat) +/- 0.02(syst).
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, João Miguel das Neves Duarte, Matthias Wolf, Varun Sharma, Yi Zhang, Tian Cheng, Yixing Chen, Alexis Kalogeropoulos, Ioannis Papadopoulos, Hua Zhang, Siyuan Wang, Xin Chen, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Rakesh Chawla, Jan Steggemann, Konstantin Androsov, Anna Mascellani, Federica Legger, Matteo Galli, Gabriele Grosso
Milica Rakic, Tatiana Pieloni, Guillaume Clément Broggi, Giovanni Iadarola, Félix Simon Carlier