分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: On the basis of the study of inclusive hadronic events, two methods are adopted to determine the number of produced ψ(2S) events collected by BES in 2001-2002 run, which is 14:0 £ 106 with the uncertainty of 4%.
分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: In S- and D-wave mixing scheme, the branching ratio of ψ″→ρπ is estimated. Together with the continuum cross section of ρπ estimated by form factor, the observed cross section of ρπ production at ψ″ in e+e− experiment is calculated taking into account the interference effect between the resonance and continuum amplitudes and the initial state radiative correction. The behavior of the cross section reveals that the disappearance of ρπ signal just indicates the existence of the corresponding branching ratio Bψ″→ρπ at the order of 10−4.
分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: The e+e− decay partial width of the recently observed state, X(3872), is estimated using the ISR data collected Root s=4.03 GeV in e+e− annihilation experiment by BES at BEPC. It is found that Γe+e-Bπ+π-J/ψ<10eV at 90% C.L. if the JPC of X(3872) is 1−−. Together with the potential models and other information, we conclude that X(3872) is very unlikely to be a vector state.
分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: With the known branching ratios of ψ(2S)→π+π− and ψ(2S)→K+K−, the branching ratio of ψ(2S)→K0SK0L is calculated as a function of the relative phase between the strong and the electromagnetic amplitudes of the ψ(2S) decays. The study shows that the branching ratio of ψ(2S)→K0SK0L is sensitive to the relative phase and a measurement of the K0SK0L branching ratio will shed light on the relative phase determination in ψ(2S)→0−0− decays.
分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: The continuum one-photon annihilation at ψ(2S) in e+e-experiment is studied. Such contributions to the measured final state 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 eaches the conclusion that in order for BES to obtain the correct branching ratios on these decay modes, at least 10pb-1 of data below the ψ(2S) peak is needed.