ψ(3770 )→J/ψπ^+π^- 强跃迁过程的首次观测(英文)

First Evidence of ψ(3770) Hadronic Transition to J/ψπ^+π^-

观测到 ψ(3770 )衰变到J ψπ+ π-非DD末态迹象 .利用工作在北京正负电子对撞机上的北京谱仪探测器在质心系能量 3.773GeV附近获取的 8.0± 0 .5pb-1数据样本 ,共观测到 6 .8± 3.0个 ψ(3770 )→J ψπ+ π-事例 .由此得到的分支比为BF(ψ(3770 )→J ψπ+ π-) =(0 .5 9± 0 .2 6± 0 .16 ) % ,其对应的分宽度为Γ(ψ(3770 )→J ψπ+ π-) =(139± 6 1± 4 1)keV .

Evidence of ψ(3770) decays to a non-D*$D final state is observed. A total of 6.8±3.0 ψ(3770)→J/ψ*!π +π - events are obtained from a data sample of 8.0±0.5 pb -1 taken at center-of-mass energies around 3.773GeV using the BES-Ⅱ detector at the BEPC. The branching fraction is determined to be BF(ψ(3770)→J/ψ*!π +π -)=(0.59±0.26±0.16)髎, corresponding to the partial width of Γ(ψ(3770)→J/ψ*!π +π -)=(139±61±41)keV.