Precise measurement of the χ c 0 resonance parameters and branching fractions of χ c 0, c 2 → π + π − / K + K − * * Supported in part by National Key R&D Program of China (2020YFA0406300, 2020YFA0406400, 2023YFA1606000); National Natural Science Foundation of China (NSFC) (11635010, 11735014, 11935015, 11935016, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819); the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1832207); 100 Talents Program of CAS; (ZR2022JQ02, ZR2024QA151) supported by Shandong Provincial Natural Science Foundation; supported by the China Postdoctoral Science Foundation (2023M742100); The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG (FOR5327, GRK 2149); Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299); Ministry of Development of Turkey (DPT2006K-120470); National Research Foundation of Korea (NRF-2022R1A2C1092335); National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand (B16F640076, B50G670107); Polish National Science Centre (2019/35/O/ST2/02907); Swedish Research Council (2019.04595); The Swedish Foundation for International Cooperation in Research and Higher Education (CH2018-7756); U. S. Department of Energy (DE-FG02-05ER41374)

Journal article

By analyzing a data sample containing events taken with the BESIII detector at the BEPCII storage ring in 2009, the resonance parameters are precisely measured using events. The mass of is determined to be ) MeV/ , and its full width is , where the first uncertainty is statistical, the second systematic, and the third for mass comes from mass uncertainty. These measurements improve the precision of mass by a factor of four and width by one order of magnitude over the previous individual measurements, and significantly boost our knowledge about the charmonium spectrum. Together with additional data events taken in 2012, the decay branching fractions of are measured as well, with precision improved by a factor of three compared to previous measurements. These decay branching fractions provide important inputs for the study of glueballs.

Authors: Ablikim, M; Achasov, MN; Adlarson, P; Afedulidis, O; Ai, XC

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Chinese Physics C
• Volume: 49
• Issue: 9
• Article number: 091001
• Publication date: 2025-09-01
• DOI: 10.1088/1674-1137/ade95f
• ISSN: 1674-1137
• Language: English
• Keywords: χ c0; BESIII; branching fraction; resonance parameter; charmonium