Search forC-parity violation inJ/ψ→γγandγϕ

M. Ablikim, M. N. Achasov, X. C. Ai, O. Albayrak, M. Albrecht, D. J. Ambrose, A. Amoroso, F. F. An, Q. An, J. Z. Bai, R. Baldini Ferroli, Y. Ban (+382 others)
2014 Physical Review D  
Using 1.06×10^8 ψ(3686) events recorded in e^+e^- collisions at √(s)= 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/ψ→γγ and γϕ decays via ψ(3686) → J/ψπ^+π^-. No significant signals are observed in either channel. Upper limits on the branching fractions are set to be B(J/ψ→γγ) < 2.7 × 10^-7 and B(J/ψ→γϕ) < 1.4 × 10^-6 at the 90% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.
doi:10.1103/physrevd.90.092002 fatcat:vtj6z4w6nbf7jgosdemyhesfbm