Measurement of the branching fractions for j/ψ → γπ0, γη and γη′ and study of η′ → γπ+π- decay dynamics
International Journal of Modern Physics A(2007)
摘要
The decay modes J/ψ → γπ0, γη, and γη′ are analyzed using a data sample of 58 million J/ψ decays collected with the BESII detector at the BEPC. The branching fractions are determined to be , Br(J/ψ → γη) = (11.23 ± 0.89) × 10-4, and Br(J/ψ → γη′) = (5.55 ± 0.44) × 10-3, where the errors are combined statistical and systematic errors. The ratio of partial widths and the singlet-octet pseudoscalar mixing angle of η-η′ system is determined. The η′ → γπ+π- decay dynamics is studied using 22,000 reconstructed J/ψ → γη′ → γγπ+π- events, the π+π- mass spectrum is fitted using different theoretical descriptions. The preliminary results show that only the ρ(770) is not enough to describe the η′ → γπ+π- decay process and a non-ρ(770) contribution is needed.
更多查看译文
关键词
branching fraction,dynamics,pseudoscalar
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要