Observation of ψ (3686) →e+e-χcJ and χcJ →e+e-J /ψ


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Ablikim M., Achasov M., Ai X., Albayrak O., Albrecht M., Ambrose D., ...More

Physical Review Letters, vol.118, no.22, 2017 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 118 Issue: 22
  • Publication Date: 2017
  • Doi Number: 10.1103/physrevlett.118.221802
  • Journal Name: Physical Review Letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Ankara University Affiliated: Yes

Abstract

Using 4.479×108 ψ(3686) events collected with the BESIII detector, we search for the decays ψ(3686)→e+e-χcJ and χcJ→e+e-J/ψ, where J=0, 1, 2. The decays ψ(3686)→e+e-χcJ and χcJ→e+e-J/ψ are observed for the first time. The measured branching fractions are B(ψ(3686)→e+e-χcJ)=(11.7±2.5±1.0)×10-4, (8.6±0.3±0.6)×10-4, (6.9±0.5±0.6)×10-4 for J=0, 1, 2, and B(χcJ→e+e-J/ψ)=(1.51±0.30±0.13)×10-4, (3.73±0.09±0.25)×10-3, (2.48±0.08±0.16)×10-3 for J=0, 1, 2, respectively. The ratios of the branching fractions B(ψ(3686)→e+e-χcJ)/B(ψ(3686)→γχcJ) and B(χcJ→e+e-J/ψ)/B(χcJ→γJ/ψ) are also reported. Also, the α values of helicity angular distributions of the e+e- pair are determined for ψ(3686)→e+e-χc1,2 and χc1,2→e+e-J/ψ.