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

Using 4.479 × 108 ψð3686Þ events collected with the BESIII detector, we search for the decays ψð3686Þ → eþe−χcJ and χcJ → eþe−J=ψ, where J ¼ 0, 1, 2. The decays ψð3686Þ → eþe−χcJ and χcJ → eþe−J=ψ are observed for the first time. The measured branching fractions are B(ψð3686Þ → eþe−χcJ) ¼ ð11.7 2.5...

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