Using a sample of 1.31×109 J/ψ events collected with the BESIII detector, we perform a study of J/ψ→γηηη′ to search for the X(2370) and ηc in the ηηη′ invariant mass distribution. No significant signal for the X(2370) is observed, and we set an upper limit for the product branching fraction of B(J/ψ→γX(2370)·B(X(2370)→ηηη′)<9.2×10-6 at the 90% confidence level. A clear ηc signal is observed for the first time, yielding a product branching fraction of B(J/ψ→γηc)·B(ηc→ηηη′)=(4.86±0.62(stat)±0.45(sys))×10-5.
Bibliographical noteFunding Information:
The BESIII Collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work was supported in part by National Key Basic Research Program of China under Contract No. 2015CB856700; National Natural Science Foundation of China (NSFC) under Contracts No. 11625523, No. 11635010, No. 11675183, No. 11735014, No. 11822506, No. 11835012, No. 11922511, No. 11935015, No. 11935016, No. 11935018, No. 11961141012 and No. 12061131003; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts No. U1732103, No. U1732263, and No. U1832207; CAS Key Research Program of Frontier Sciences under Contracts No. QYZDJ-SSW-SLH003 and No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; ERC under Contract No. 758462; German Research Foundation DFG under Contract No. 443159800, Collaborative Research Center CRC 1044, FOR 2359, FOR 2359, GRK 214; Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Science and Technology fund; Olle Engkvist Foundation under Contract No. 200-0605; STFC (United Kingdom); the Knut and Alice Wallenberg Foundation (Sweden) under Contract No. 2016.0157; The Royal Society, UK under Contracts No. DH140054 and No. DH160214; the Swedish Research Council; U.S. Department of Energy under Contracts No. DE-FG02-05ER41374 and No. DE-SC-0012069.
© 2021 authors. Published by the American Physical Society.