e^+e^- 实验中ψ ( 2S)能区连续态单光子湮没过程的贡献(英文)

Contribution of One-Photon Annihilation at ψ(2S) in e^+e^- Experiment

研究了e+e-实验中 ψ( 2S)能区连续态单光子湮没过程的截面对观测总截面的贡献 .针对 ψ( 2S)质量处ωπ0 和π+π-两个观测末态 ,利用唯象模型估计了单光子湮没过程贡献的大小 .分析表明 ,对于 ψ( 2S)→ωπ0 和 ψ( 2S)→π+π-,以及其他电磁末态分支比的确定 ,单光子湮没过程的贡献必须认真考虑 .通过研究 ,我们认为对于BES实验来说 ,为了获得共振态电磁末态分支比的正确结果 ,至少需要在低于 ψ( 2S)共振峰的能量点采集 10pb-1的数据 .

The continuum one-photon annihilation at ψ(2S) in e+e- experiment is studied. Such contributions to the measured final states ωπ0 and π+π- at ψ(2S) mass are estimated by phenomenological models. It is found that these contributions must be taken into account in the determination of branching ratios of ψ(2S)→ωπ0 and ψ(2S)→π+π-, as well as other electromagnetic decay modes. The study reaches the conclusion that in order to obtain the correct branching ratios on these decay modes at BES, at least 10pb -1 of data below the ψ(2S) peak is needed.