Observation of J /ψ Electromagnetic Dalitz Decays to X (1835), X (2120), and X (2370)

Date Issued
08-07-2022
Author(s)
Ablikim, M.
Achasov, M. N.
Adlarson, P.
Ahmed, S.
Albrecht, M.
Aliberti, R.
Amoroso, A.
An, M. R.
An, Q.
Bai, X. H.
Bai, Y.
Bakina, O.
Baldini Ferroli, R.
Balossino, I.
Ban, Y.
Begzsuren, K.
Berger, N.
Bertani, M.
Bettoni, D.
Bianchi, F.
Bloms, J.
Bortone, A.
Boyko, I.
Briere, R. A.
Cai, H.
Cai, X.
Calcaterra, A.
Cao, G. F.
Cao, N.
Cetin, S. A.
Chang, J. F.
Chang, W. L.
Chelkov, G.
Chen, D. Y.
Chen, G.
Chen, H. S.
Chen, M. L.
Chen, S. J.
Chen, X. R.
Chen, Y. B.
Chen, Z. J.
Cheng, W. S.
Cibinetto, G.
Cossio, F.
Cui, X. F.
Dai, H. L.
Dai, X. C.
Dbeyssi, A.
De Boer, R. E.
Dedovich, D.
Deng, Z. Y.
Denig, A.
Denysenko, I.
Destefanis, M.
De Mori, F.
Ding, Y.
Dong, C.
Dong, J.
Dong, L. Y.
Dong, M. Y.
Dong, X.
Du, S. X.
Fan, Y. L.
Fang, J.
Fang, S. S.
Fang, Y.
Farinelli, R.
Fava, L.
Feldbauer, F.
Felici, G.
Feng, C. Q.
Feng, J. H.
Fritsch, M.
Fu, C. D.
Gao, Y.
Gao, Y.
Gao, Y.
Gao, Y. G.
Garzia, I.
Ge, P. T.
Geng, C.
Gersabeck, E. M.
Gilman, A.
Goetzen, K.
Gong, L.
Gong, W. X.
Gradl, W.
Greco, M.
Gu, L. M.
Gu, M. H.
Gu, S.
Gu, Y. T.
Guan, C. Y.
Guo, A. Q.
Guo, L. B.
Guo, R. P.
Guo, Y. P.
Guskov, A.
Han, T. T.
Han, W. Y.
DOI
Abstract
Using a sample of about 1010 J/ψ events collected at a center-of-mass energy s=3.097 GeV with the BESIII detector, the electromagnetic Dalitz decays J/ψ→e+e-π+π-η′, with η′→γπ+π- and η′→π+π-η, have been studied. The decay J/ψ→e+e-X(1835) is observed with a significance of 15σ, and also an e+e- invariant-mass dependent transition form factor of J/ψ→e+e-X(1835) is presented for the first time. The intermediate states X(2120) and X(2370) are also observed in the π+π-η′ invariant-mass spectrum with significances of 5.3σ and 7.3σ. The corresponding product branching fractions for J/ψ→e+e-X, X→π+π-η′ [X=X(1835), X(2120), and X(2370)] are reported.
Volume
129