TY - JOUR
T1 - Observation of ψ (3686) →e+e-χcJ and χcJ →e+e-J /ψ
AU - Ablikim, M.
AU - Achasov, M. N.
AU - Ai, X. C.
AU - Albayrak, O.
AU - Albrecht, M.
AU - Ambrose, D. J.
AU - Amoroso, A.
AU - Haddadi, Z.
AU - Kalantar-Nayestanaki, N.
AU - Kavatsyuk, M.
AU - Löhner, H.
AU - Messchendorp, J.
AU - Tiemens, M.
AU - BESIII Collaboration
PY - 2017/5/30
Y1 - 2017/5/30
N2 - 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.
AB - 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.
KW - PARTICLE
U2 - 10.1103/PhysRevLett.118.221802
DO - 10.1103/PhysRevLett.118.221802
M3 - Article
SN - 0031-9007
VL - 118
JO - Physical Review Letters
JF - Physical Review Letters
IS - 22
M1 - 221802
ER -