@article{13bbe428ceaa4986a8976936c81f5acf,
title = "An improved limit for Γee of X(3872) and Γee measurement of ψ(3686)",
abstract = "Using the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e+e-→γISRX(3872)→γISRπ+π-J/ψ via the Initial State Radiation technique. The production of a resonance with quantum numbers JPC=1++ such as the X(3872) via single photon e+e- annihilation is forbidden, but is allowed by a next-to-leading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Γee X(3872)B(X(3872)→π+π-J/ψ)<0.13 eV at the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the ψ(3686) to be Γee ψ(3686)=2213±18stat±99sys eV.",
keywords = "BESIII, Charmonium spectroscopy, X(3872), Γ, ψ(3686)",
author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and Ai, {X. C.} and O. Albayrak and M. Albrecht and Ambrose, {D. J.} and A. Amoroso and An, {F. F.} and Q. An and Bai, {J. Z.} and {Baldini Ferroli}, R. and Y. Ban and Bennett, {D. W.} and Bennett, {J. V.} and M. Bertani and D. Bettoni and Bian, {J. M.} and F. Bianchi and E. Boger and O. Bondarenko and I. Boyko and Briere, {R. A.} and H. Cai and X. Cai and O. Cakir and A. Calcaterra and Cao, {G. F.} and Cetin, {S. A.} and Chang, {J. F.} and G. Chelkov and G. Chen and Chen, {H. S.} and Chen, {H. Y.} and Chen, {J. C.} and Chen, {M. L.} and Chen, {S. J.} and X. Chen and Chen, {X. R.} and Chen, {Y. B.} and Cheng, {H. P.} and Chu, {X. K.} and G. Cibinetto and D. Cronin-Hennessy and Dai, {H. L.} and Dai, {J. P.} and A. Dbeyssi and D. Dedovich and Deng, {Z. Y.} and A. Denig and I. Denysenko",
note = "Publisher Copyright: {\textcopyright} 2015 The Authors.",
year = "2015",
month = oct,
day = "7",
doi = "10.1016/j.physletb.2015.08.013",
language = "English",
volume = "749",
pages = "414--420",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier",
}