We report on a search for Y(2S)->eta_b(1S) decay based on analysis of the inclusive photon spectrum of 24.7 fb^-1 of e+e- collisions at the Y(2S) center-of-mass energy collected with the Belle detector at the KEKB asymmetric energy e+e- collider. We measure a branching fraction of B(Y(2S)->eta_b(1S)) = (6.1+/-0.9)x10^-4, and derive an eta_b(1S) mass of 9397.7+/-3.0 MeV/c^2. This
mass value is in good agreement with the current world average, and this measurement represents
the first significant observation of this decay mode.
Revised: January 21, 2020 |
Published: December 7, 2018
Citation
Fulsom B.G., T. Pedlar, I. Adachi, H. Aihara, S. Al Said, D. Asner, and H. Atmacan, et al. 2018.Observation of Y( 2S )-> ynb(1S) Decay.Physical Review Letters 121, no. 23:Article No. 232001.PNNL-SA-130815.doi:10.1103/PhysRevLett.121.232001