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.
Original language | English (US) |
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Article number | 221802 |
Journal | Physical review letters |
Volume | 118 |
Issue number | 22 |
DOIs | |
State | Published - May 30 2017 |