Observation of ψ(3686)→ηe+e

BESIII Collaboration

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Using a data sample of 448.1×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay ψ(3686)→ηe+e, with significances of 7.0σ and 6.3σ when reconstructing the η meson via its decay modes η→γπ+π and η→π+πη (η→γγ), respectively. The weighted average branching fraction is determined to be B(ψ(3686)→ηe+e)=(1.90±0.25±0.11)×10−6, where the first uncertainty is statistical and the second systematic.

Original languageEnglish (US)
Pages (from-to)452-458
Number of pages7
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
StatePublished - Aug 10 2018

Bibliographical note

Funding 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 National Key Basic Research Program of China under Contract No. 2015CB856700 ; National Natural Science Foundation of China (NSFC) under Contracts Nos. 11235011 , 11335008 , 11425524 , 11625523 , 11635010 ; 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 Nos. U1232105 , U1332201 , U1532257 , U1532258 ; CAS Key Research Program of Frontier Sciences under Contracts Nos. QYZDJ-SSW-SLH003 , QYZDJ-SSW-SLH040 ; 100 Talents Program of CAS ; National 1000 Talents Program of China ; INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology ; German Research Foundation DFG under Contracts Nos. Collaborative Research Center CRC 1044 , 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 Nos. DE-FG02-05ER41374 , DE-SC-0010118 , DE-SC-0010504 , DE-SC-0012069 ; 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 .


  • Charmonium
  • Dalitz decay
  • ee Annihilation

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