摘要
利用北京谱仪采集的 1400万Ψ′数据,对粲偶素衰变到赝标介子对KSKL进行了寻找,首次观测到信号并测量了其衰变分支比,并首次确定Ψ′衰变中强振幅和电磁振幅之间的相角接近±90°.结合从北京谱仪采集的J/Ψ数据中测得的J/Ψ→KSKL的分支比,确定了Ψ′→KSKL相对于微扰量子色动力学“12%”规则的反常增强,对粲偶素的衰变机制研究提出了新的挑战.
The transition Ψ′→K SK L has been observed for the first time using the 14 million Ψ′ events collected by the Beijing Spectrometer of the Beijing Electron-Positron Collider. Based on this, the relative phase between the strong and electromagnetic amplitudes of Ψ′ decays is found to be around±90 degree. Together with improved measurement of the J/Ψ→K SK L branching fraction, Ψ′→K SK L is found to be enhanced compared with the pQCD '12%' rule between Ψ′ and J/Ψ decays. This is a new challenge in the study of charmonium decay dynamics.
出处
《物理》
CAS
北大核心
2005年第2期112-114,共3页
Physics
基金
中国科学院"百人计划"资助项目
