Decays χcJ(J=0,1,2)→ωφ are studied using (448.1±2.9)×106ψ(3686) events collected with the BESIII detector in 2009 and 2012. In addition to the previously established χc0→ωφ, the first observation of χc1→ωφ is reported in this paper. The measured product branching fractions are B(ψ(3686)→γχc0)×B(χc0→ωφ)=(13.83±0.70±1.01)×10-6 and B(ψ(3686)→γχc1)×B(χc1→ωφ)=(2.67±0.31±0.27)×10-6, and the absolute branching fractions are B(χc0→ωφ)=(13.84±0.70±1.08)×10-5 and B(χc1→ωφ)=(2.80±0.32±0.30)×10-5. We also find strong evidence for χc2→ωφ with a statistical significance of 4.8σ, and the corresponding product and absolute branching fractions are measured to be B(ψ(3686)→γχc2)×B(χc2→ωφ)=(0.91±0.23±0.12)×10-6 and B(χc2→ωφ)=(1.00±0.25±0.14)×10-5. Here, the first errors are statistical and the second ones systematic.
Bibliographical noteFunding Information:
The BESIII Collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work is supported in part by the National Key Basic Research Program of China under Contract No. 2015CB856700; National Natural Science Foundation of China (NSFC) under Contracts No. 11335008, No. 11425524, No. 11625523, No. 11635010, No. 11735014, and No. 11605042; 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 under Contracts No. U1632109, No. U1532257, No. U1532258, and No. U1732263; CAS Key Research Program of Frontier Sciences under Contracts No. QYZDJ-SSW-SLH003 and No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; CAS Open Research Program of Large Research Infrastructures under Contract No. 1G2017IHEPKFYJ01; INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG under Collaborative Research Center Contracts No. CRC 1044 and No. FOR 2359; Istituto Nazionale di Fisica Nucleare, Italy; Koninklijke Nederlandse Akademie van Wetenschappen (KNAW) under Contract No. 530-4CDP03; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Science and Technology Fund; The Swedish Research Council; U.S. Department of Energy under Contracts No. DE-FG02-05ER41374, No. DE-SC-0010118, No. DE-SC-0010504, and No. DE-SC-0012069; University of Groningen (RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt; China Postdoctoral Science Foundation under Contract No. 2017M622347, Post-doctoral research start-up fees of Henan Province under Contract No. 2017SBH005 and Ph.D research start-up fees of Henan Normal University under Contract No. qd16164; Program for Innovative Research Team in University of Henan Province (Grant No. 19IRTSTHN018).