Study ofψ(2S)decays toXJ/ψ

M. Ablikim, J. Z. Bai, Y. Ban, J. G. Bian, X. Cai, J. F. Chang, H. F. Chen, H. S. Chen, H. X. Chen, J. C. Chen, Jin Chen, Jun Chen (+194 others)
2004 Physical Review D  
Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) -> pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026 \pm 0.055.
doi:10.1103/physrevd.70.012003 fatcat:uriix4vyeve6ja53wfliwgeatq