分类: 物理学 >> 核物理学 提交时间: 2016-09-12
摘要: We review the results on the XYZ states from the Belle experiment, including the measurement of inclusive hadronic cross sections and exclusive cross sections in e+e- annihilation and the Z_b states in the bottomonium energy region; and the study of the Y states and the Z_c states in charmonium energy region.
分类: 物理学 >> 核物理学 提交时间: 2016-09-12
摘要: With its unique data samples at energies of 3.8--4.6 GeV, the BESIII experiment made a significant contribution to the study of charmonium and charmonium-like states, i.e., the XYZ states. We review the results for observations of the Zc(3900) and Zc(4020) states, the X(3872) in e+e- annihilation, and charmonium psi(1^3D_2) state, as well as measurements of the cross-sections of omega chi_cJ and eta J/psi, and the search for e+e- to gamma chi_cJ and gamma Y(4140). We also present data from BESIII that may further strengthen the study of the XYZ and conventional charmonium states, and discuss perspectives on future experiments.
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 theoretical explanations about the "ρπ puzzle" in charmonium decays are reviewed exten-sively, and the comparison of theoretical predications with experimental data is made whenever possible. Three methods to estimate the ratio of the branching fractions of J/ψ and ψ′decays are also discussed. It is pointed out that in order to understand the ρπ puzzle, and the dynamics of charmonium decays, systematic studies should be made in theory, phenomenology and experiment aspects.
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.
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%.