Ablikim, M.An, M.R.Ahmed, S.Bai, X.H.Kolcu, Onur BuğraÇetin, Serkant AliShang, K. Y.Shangguan, L.Shi, H.Schoenning, M.2022-08-172022-08-172022Ablikim, M., Achasov, M. N., Adlarson, P., Ahmed, S., Albrecht, M., Aliberti, R., . . . BESIII Collaboration. (2022). Observation of a state X(2600) in the π^{+}π^{-}η' system in the process J/ψ→γπ^{+}π^{-}η'. Physical Review Letters, 129(4), 042001. doi:10.1103/PhysRevLett.129.0420010031-9007http://doi.org/10.1103/PhysRevLett.129.042001https://hdl.handle.net/20.500.12713/3095Based on (10087±44)×10^{6}??J/? events collected with the BESIII detector, the process J/????^{+}?^{-}?^{'} is studied using two largest decay channels of the ?^{'} meson, ?^{'}???^{+}?^{-} and ?^{'}???^{+}?^{-}, ????. A new resonance, which we denote as the X(2600), is observed with a statistical significance larger than 20? in the ?^{+}?^{-}?^{'} invariant mass spectrum, and it has a connection to a structure around 1.5??GeV/c^{2} in the ?^{+}?^{-} invariant mass spectrum. A simultaneous fit on the ?^{+}?^{-}?^{'} and ?^{+}?^{-} invariant mass spectra with the two ?^{'} decay modes indicates that the mass and width of the X(2600) state are 2618.3±2.0_{-1.4}^{+16.3}??MeV/c^{2} and 195±5_{-17}^{+26}??MeV, where the first uncertainties are statistical, and the second systematic.eninfo:eu-repo/semantics/closedAccessMass SpectrometryMesonStatistical SignificanceUncertaintyArticle1294WOS:0008409476000022-s2.0-85135552304Q110.1103/PhysRevLett.129.042001Q1