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arXiv · 1403.7042

Observation of Electromagnetic Dalitz decays J/ψ\to P e^+e^-

M. Ablikim·M. N. Achasov·X. C. Ai·O. Albayrak·M. Albrecht·D. J. Ambrose·F. F. An·Q. An·J. Z. Bai·R. Baldini Ferroli·Y. Ban·J. V. Bennett·M. Bertani·J. M. Bian·E. Boger·O. Bondarenko·I. Boyko·S. Braun·R. A. Briere·H. Cai·X. Cai·O. Cakir·A. Calcaterra·G. F. Cao·S. A. Cetin·J. F. Chang·G. Chelkov·G. Chen·H. S. Chen·J. C. Chen·M. L. Chen·S. J. Chen·X. Chen·X. R. Chen·Y. B. Chen·H. P. Cheng·X. K. Chu·Y. P. Chu·D. Cronin-Hennessy·H. L. Dai·J. P. Dai·D. Dedovich·Z. Y. Deng·A. Denig·I. Denysenko·M. Destefanis·W. M. Ding·Y. Ding·C. Dong·J. Dong·L. Y. Dong·M. Y. Dong·S. X. Du·J. Z. Fan·J. Fang·S. S. Fang·Y. Fang·L. Fava·C. Q. Feng·C. D. Fu·J. L. Fu·O. Fuks·Q. Gao·Y. Gao·C. Geng·K. Goetzen·W. X. Gong·W. Gradl·M. Greco·M. H. Gu·Y. T. Gu·Y. H. Guan·A. Q. Guo·L. B. Guo·T. Guo·Y. P. Guo·Y. L. Han·F. A. Harris·K. L. He·M. He·Z. Y. He·T. Held·Y. K. Heng·Z. L. Hou·C. Hu·H. M. Hu·J. F. Hu·T. Hu·G. M. Huang·G. S. Huang·H. P. Huang·J. S. Huang·L. Huang·X. T. Huang·Y. Huang·T. Hussain·C. S. Ji·Q. Ji·Q. P. Ji·X. B. Ji
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Abstract

Based on a sample of (225.3\pm2.8)\times 10^{6} J/ψevents collected with the BESIII detector, the electromagnetic Dalitz decays of J/ψ\to P e^+e^-(P=η'/η/π^0) are studied. By reconstructing the pseudoscalar mesons in various decay modes, the decays J/ψ\to η' e^+e^-, J/ψ\to ηe^+e^- and J/ψ\to π^0 e^+e^- are observed for the first time. The branching fractions are determined to be \mathcal{B}(J/ψ\to η' e^+e^-) = (5.81\pm0.16\pm0.31)\times10^{-5}, \mathcal{B}(J/ψ\to ηe^+e^-) = (1.16\pm0.07\pm0.06)\times10^{-5}, and \mathcal{B}(J/ψ\to π^0 e^+e^-)=(7.56\pm1.32\pm0.50)\times10^{-7}, where the first errors are statistical and the second ones systematic.

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M. Ablikim, M. N. Achasov, X. C. Ai, O. Albayrak, M. Albrecht, D. J. Ambrose, F. F. An, Q. An, J. Z. Bai, R. Baldini Ferroli, Y. Ban, J. V. Bennett, M. Bertani, J. M. Bian, E. Boger, O. Bondarenko, I. Boyko, S. Braun, R. A. Briere, H. Cai, X. Cai, O. Cakir, A. Calcaterra, G. F. Cao, S. A. Cetin, J. F. Chang, G. Chelkov, G. Chen, H. S. Chen, J. C. Chen, M. L. Chen, S. J. Chen, X. Chen, X. R. Chen, Y. B. Chen, H. P. Cheng, X. K. Chu, Y. P. Chu, D. Cronin-Hennessy, H. L. Dai, J. P. Dai, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, W. M. Ding, Y. Ding, C. Dong, J. Dong, L. Y. Dong, M. Y. Dong, S. X. Du, J. Z. Fan, J. Fang, S. S. Fang, Y. Fang, L. Fava, C. Q. Feng, C. D. Fu, J. L. Fu, O. Fuks, Q. Gao, Y. Gao, C. Geng, K. Goetzen, W. X. Gong, W. Gradl, M. Greco, M. H. Gu, Y. T. Gu, Y. H. Guan, A. Q. Guo, L. B. Guo, T. Guo, Y. P. Guo, Y. L. Han, F. A. Harris, K. L. He, M. He, Z. Y. He, T. Held, Y. K. Heng, Z. L. Hou, C. Hu, H. M. Hu, J. F. Hu, T. Hu, G. M. Huang, G. S. Huang, H. P. Huang, J. S. Huang, L. Huang, X. T. Huang, Y. Huang, T. Hussain, C. S. Ji, Q. Ji, Q. P. Ji, X. B. Ji. 2014-05-21. Observation of Electromagnetic Dalitz decays J/ψ\to P e^+e^-. https://doi.org/10.1103/physrevd.89.092008

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