Observation of a State X (2600) in the π+π-η′ System in the Process J/ψ →γπ+π-η′

Date Issued
22-07-2022
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.
Batozskaya, V.
Becker, D.
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, C.
Chen, G.
Chen, H. S.
Chen, M. L.
Chen, S. J.
Chen, T.
Chen, X. R.
Chen, X. T.
Chen, Y. B.
Chen, Z. J.
Cheng, W. S.
Cibinetto, G.
Cossio, F.
Cui, J. J.
Cui, X. F.
Dai, H. L.
Dai, J. P.
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.
Egorov, P.
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. N.
Gao, Yang
Garzia, I.
Ge, P. T.
Geng, C.
Gersabeck, E. M.
Gilman, A.
Goetzen, K.
Gong, L.
Gong, W. X.
Gradl, W.
Greco, M.
Gu, M. H.
Guan, C. Y.
Guo, A. Q.
Guo, A. Q.
Guo, L. B.
Guo, R. P.
Guo, Y. P.
DOI
Abstract
Based on (10087±44)×106 J/ψ events collected with the BESIII detector, the process J/ψ→γπ+π-η′ is studied using two largest decay channels of the η′ meson, η′→γπ+π- and η′→ηπ+π-, η→γγ. A new resonance, which we denote as the X(2600), is observed with a statistical significance larger than 20σ in the π+π-η′ invariant mass spectrum, and it has a connection to a structure around 1.5 GeV/c2 in the π+π- invariant mass spectrum. A simultaneous fit on the π+π-η′ and π+π- invariant mass spectra with the two η′ decay modes indicates that the mass and width of the X(2600) state are 2618.3±2.0-1.4+16.3 MeV/c2 and 195±5-17+26 MeV, where the first uncertainties are statistical, and the second systematic.
Volume
129