Search for the Radiative Transitions ψ(3770)→γη_c and γη_c(2S)


By using a 2.92 fb⁻¹ data sample taken at √s=3.773 GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions ψ(3770) → γη_c and γη_c(2S) through the hadronic decays η_c(η_c(2S)) → K_s^0 K^± π^∓. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be ℬ(ψ(3770)→γη_c) × ℬ(η_c→K_s^0 K^± π^∓) < 1.6×10⁻⁵ and ℬ(ψ(3770)→γη_c(2S)) × ℬ(η_c(2S)→K_s^0 K^± π^∓) < 5.6×10⁻⁶. Combining our result with world-average values of ℬ(η_c(η_c(2S))→K_s^0 K^± π^∓), we find the branching fractions ℬ(ψ(3770)→γη_c) < 6.8×10⁻⁴ and ℬ(ψ(3770)→γη_c(2S)) < 2.0×10⁻³ at a 90% confidence level.



Branching fractions (Nuclear physics), Hadrons--Decay, Photons, Radiative transitions

"This work is supported in part by the Ministry of Science and Technology of China under Contract No. 2009CB825200; Joint Funds of the National Natural Science Foundation of China under Contracts No. 11079008, No. 11179007, No. 11179014, No. 11179020, and No. U1332201; National Natural Science Foundation of China (NSFC) under Contracts No. 10625524, No. 10821063, No. 10825524, No. 10835001, No. 10935007, No. 11125525, and No. 11235011; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; CAS under Contracts No. KJCX2-YW-N29 and No. KJCX2-YW-N45; 100 Talents Program of CAS; German Research Foundation DFG under Contract No. Collaborative Research Center CRC-1044; Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey under Contract No. DPT2006K-120470; U.S. Department of Energy under Contracts No. DE-FG02-04ER41291, No. DE-FG02-05ER41374, No. DE-FG02-94ER40823, and No. DESC0010118; U.S. National Science Foundation; University of Groningen (RuG) and the Helmholtzzentrum fuer Schwerionenforschung GmbH (GSI), Darmstadt; WCU Program of National Research Foundation of Korea under Contract No. R32-2008-000-10155-0."


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