线性σ模型和在J/Ψ→γp的p质量谱中观测到的增强现象(英文)

假定BES合作组在辐射衰变J/ψ-γpp-中观测到的pp-谱的增强是由于存在一个pp-的分子态,用线性σ 模型计算了它的束缚能和寿命．具体考虑了这种增强现象是由于pp-可能形成一个S波或P波共振态,并把计算 结果和实验数据做了比较．与氚核不同,由于pp-可以通过s道湮没,因此通过研究它的总宽度可以获得线性σ模 型及其相关问题的信息．     

S-D混合与φ(3770)的电偶极跃迁

本文在粲偶素势模型的框架内,讨论了φ(3770)与φ(3686)之间的2~3S_1-1~3D_1混合对φ(3770)与φ(3686)电偶极跃迁的影响。结论是混合角θ=30°应子排除,而θ=—10°虽然可以对φ(3770)→X_0γ和φ(3686)→X_0γ给出改善的结果,但仍不能解决φ(3770)→X_1γ与实验的矛盾。     

An improved variational method

In order to improve the unitarity of the S-matrix, an improved variational formulism is derived by proposing new generating functionals and adopting proper asymptotic boundary conditions for trial relative wave functions. The formulas with the weighted line-column balance for the single-channel and multi-channel scatterings, where the non-central interaction is implicitly considered, are presented. A numerical check is performed with a soluble model in a four coupled channel scattering problem. The result shows that the high accuracy and the unitarity of the S-matrix are reached.     

改变地球面貌的十大公式

 1971年尼加拉瓜发行了一套共十枚特种邮票。每枚邮票上印有一个数学公式,并配以精美的图案,描绘公式的推论或应用,邮票的背面还用西班牙文记载了这个公式的历史背景及在改变地球面貌方面起的作用。     

关于η_c′粒子及其电磁衰变

本文在势模型的框架内,估算了η′_c粒子的质量、宽度及几种主要电磁衰变道的分支比。指出禁戒型磁跃迁η′_c→J/φγ的相对论修正结果比简单的非相对论估算有可能大一个量级。讨论了北京正负电子对撞机(BEPC)对级联电磁辐射过程φ′(3686)→γη′_c→γγ~1P_1,γγJ/φ,3γ进行测量的可能性。     

关于ψ(3770)的电偶极跃迁

本文采用一种以QCD为基础的势模型,计算了cc态的各种E1跃迁宽度.结果表明相对论修正效应相当重要.所得ψ(2s)→γχ_cJ和χ_cJ→γψ(1S)(J=0,1,2)的跃迁宽度与实验符合,但ψ(3770)→γχ_cJ跃迁宽度要比MarkⅢ实验组的新近结果小2倍左右.改善理论结果的一个可能性是考虑2³S₁—1³D1混合的效应.     

径向升降算符及其应用(Ⅱ)

本文是在前文［１］的基础上，讨论径向升降算符在平均值和矩阵元的计算中的应用．     

Possible heavy dibaryons

In the framework of the constituent quark model, the possible S-wave heavy dibaryon states with the c flavor are investigated. The factors which are responsible for the binding behavior of the dibaryon system are analyzed. It is shown that both the symmetry character of the system and the energy of interactions between interacting quarks are important for the binding behavior of the two-baryon system with the heavy flavor. As a result, seven possible candidates of heavy dibaryons with c flavor are predicted.     

Testing Bell inequality at experiments of high energy physics

Besides using the laser beam, it is very tempting to directly testify the Bell inequality at high energy experiments where the spin correlation is exactly what the original Bell inequality investigates. In this work, we follow the proposal raised in literature and use the successive decays J/ψ →γηc→ ∧∧ → pπ^- pπ^＋ to testify the Bell inequality. Our goal is twofold, namely, we first make a Monte-Carlo simulation of the processes based on the quantum field theory （QFT）. Since the underlying theory is QFT, it implies that we pre-admit the validity of quantum picture. Even though the QFT is true, we need to find how big the database should be, so that we can clearly show deviations of the correlation from the Bell inequality determined by the local hidden variable theory. There have been some critiques on the proposed method, so in the second part, we suggest some improvements which may help to remedy the ambiguities indicated by the critiques. It may be realized at an updated facility of high energy physics, such as BES III.     

神奇的现代物理（快板书）

引子：最近我们翻译了诺贝尔物理奖得主维尔切克的一本高级科普名著,书名为《奇妙的现实》,不久即可面世。颇为罕见的是,书中收录了这位现代物理学大家的六首诗,用简洁的诗的语言形式介绍现代物理知识和从事物理研究工作的体会,读起来别有一番情趣。