耦合J—J型方程中的DEVIL STAIRS

通过数值计算，首次观察到Ｊ－Ｊ型方程的一些台阶，而且在Ｃｈａｏｓ状态下，有ｄｅｖｉｌ ｓｔａｉｒｓ的存在。     

打开物质微观结构的大门--电子发现者J.J.汤姆孙

简要地论述了阴极射线的研究和电子的发现过程，以及J.J.汤姆孙和勒纳德在这些研究中的贡献。     

J／ψ粒子的发现

本文回顾了Ｊ／ψ粒子的发现过程，分析了这项发现对粒子物理学发展的重大意义，并对发现Ｊ粒子的产生实验、发现ψ粒子的形成实验及发现γ粒子的实验进行了简要的评述．     

Determination of the number of J/ψ events with J/ψ → inclusive decays

The number of J/ψ events collected with the BES0 detector at the BEPC/ from June 12 to July 28, 2009 is determined to be (225:3±2:8)×10⁶ using J/ψ → inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.     

J/ψ→μ+μ- reconstruction in the CMS experiment

In this paper the J/ψ→μ+μ- reconstruction performance in the CMS experiment at the LHC is studied in detail by using B5→ J/ψψ →μμКК events. The reconstruction efficiencies of J/ψ mesons and their decay muons are obtained as a function of the transverse momentum PT and the pseudo-rapidity η. We also study the muon trigger efficiency for this channel with the planned Level-1 trigger and High Level Trigger selection criteria. It was observed that the muon reconstruction efficiency decreases when the two decay muons have a small or large 3D angular separation, which further affects the overall J/ψ reconstruction efficiency.     

Measurement of J/ψ leptonic width with the KEDR detector

We report a new precise determination of the leptonic widths of the J/psi meson performed with the KEDR detector at the VEPP-4M e+e-collider.The measured values of the J/psi parameters are: Гee×Гee/Г =0.3323±0.0064(stat.)±0.0048(syst.)keV,Гee×Гμμ/Г = 0.3318±0.0052(stat.)Г0.0063(syst.)keV.Assuming eμ universality and using the table value of the branching ratios the leptonic Г11 = 5.59±0.12 keV width and the total Г = 94.1±2.7 keV widths were obtained.We also discuss in detail a method to calculate radiative corrections at a narrow resonance.     

核形变对J/ψ压低的效应

用强子和弦级联模型,JPCIAE,研究(200A GeV)U+U中心碰撞中核形变对J/ψ压低的效应.结果表明:在两形变核的长轴都沿束流方向的碰撞中,J/ψ压低因子约为两长轴都垂直于束流方向碰撞时的二分之一.     

Feasibility study of a J/ψ cross section measurement with early CMS data

We report the methods and plans for measuring the differential cross section of J/ψ→μ+μ- production, using data to be collected in the first LHC run by the CMS detector. Making use of the large B-hadron lifetime, we show how to separate the promptly produced J/ψ's from those coming from B-hadron decays. Since the J/ψ production cross section is expected to be large, the analysis should be viable with relatively small data sets, that will become available early in the startup of the LHC. We also address effects of a non-perfect detector alignment, as well as systematic uncertainties.About 70 thousand J/ψ decays are reconstructed from Monte Carlo data, which corresponds to an integrated luminosity of 3 pb-1 in 14 TeV collisions, in the range of pJ/ψT between 5 and 40 GeV/c. The precision of the result is limited by systematic uncertainties, and is at the 15% level.     

Cold nuclear matter effects on J/ψ production in d-Au collisions

The medium modifications of J/ψ production in d-Au collisions at √SNN= 200 GeV are studied in the Glauber model. By means of the c.m. energy loss parameter per collision studied in Drell-Yan process,taking account of the inhomogeneous shadowing effect, we find that the initial-state energy loss effect can be ignored in d-Au collisions at mid-rapidity. Then, the final-state J/ψ absorption effect is also considered and the theoretical results are in good agreement with the recent experimental data given by PHENIX. Finally,the experimental results of J/ψ production in d-Pb collisions are also predicted at RHIC and LHC energies respectively.     

J/ψ核吸收新截面难以改变吸收机制的局

将新发表的J/ψ核吸收截面输入强子和弦级联模型JPCIAE,计算了200AGeV/c的P-A,O-U,S-U和Pb-Pb最小偏畸碰撞中J/ψ压低因子并与实验作比较.结果表明增大的新截面难以改变核吸收机制不易解释Pb-Pb碰撞J/ψ反常压低局面.     

关于J/ψ→Gb+γ和J/ψ→e+ē过程

基于J/ψ辐射产生胶球态Gb和湮没为e+ē对两过程的中间态和末态都不涉及任何夸克强子而只与强作用的真空性质密切相关这一特性，从另一种角度讨论了这两个过程.利用高能强作用软过程中修改后的pomeron场论模型和相关的最大非微扰强作用反应假定，并考虑到轻的和重的组分夸克在结构上的差异而在模型参数中作出相应的变更后，提出了这两个过程的另一种物理机制，计算了它们的衰变宽度，定出了胶球态与非微扰胶子间的耦合数值，并就此进行了简单的讨论. 关键词： J/ψ衰变 pomeron 非微扰     

J＇K耦合的Zeeman效应

在分析光谱数据基础上，本文以Ｎｅ原子６３２８谱线为Ｊ’Ｋ耦合Ｚｅｅｍａｎ效应实例计算了谱线在较弱磁场中的分裂情况；从而廓清了有关教材中不正确的论述。     

Partial wave analysis of J/ψ→pp(-)π~0 and measurement of J/ψ→pp(-)η, pp(-)η'

Based on 58 million J/ψ data collected with the BES Ⅱ detector at the BEPC, Partial Wave Analysis(PWA) is performed on J/ψ→pp(-)π~0. The new excited baryon N(2065) is confirmed. Clear signals for other N~* states are observed and the corresponding masses, widths and spin-parity are also measured. Processes such as J/ψ→pp(-)η,pp(-)η' are also studied and the branching ratios are measured.     

J/ψ强子衰变过程的角分布螺旋度形式

本文给出了e⁺e^－→J/ψ→V+X,V→P₁P₂和e⁺e^－→J/ψ→V+X,X→P₄P₅过程的角分布螺旋度形式.为e⁺e^－实验数据分析提供了理论公式.     

关于J/ψ→Gb+γ和J/ψ→e+(-e)过程

基于J/ψ辐射产生胶球态Gb和湮没为e-e对两过程的中间态和末态都不涉及任何夸克强子而只与强作用的真空性质密切相关这一特性,从另一种角度讨论了这两个过程.利用高能强作用软过程中修改后的pomeron场论模型和相关的最大非微扰强作用反应假定,并考虑到轻的和重的组分夸克在结构上的差异而在模型参数中作出相应的变更后,提出了这两个过程的另一种物理机制,计算了它们的衰变宽度,定出了胶球态与非微扰胶子间的耦合数值,并就此进行了简单的讨论.     

Incommensurate Antiferromagnetism in the Extended t－J Model

The effect of the extra second neighbor hopping t‘ on the incommensurate spin correlation in the t-J model in the underdoped regime is studied within the fermion-spin theory.It is shown that although the extra second neighbor hopping t‘ is systematically accompanied with the increasing of the weight of the incommensurate peaks in the dynamical spin structure factor,for the physical reasonable small value of t‘ the qualitative behavior of the incommensurate spin correlation in the t-t‘-J model is the same as in the case of t-J model.     

J/ψ辐射衰变产物自旋宇称分析的实验方法

利用蒙特卡罗数据研究、讨论了J/ψ辐射衰变产生物自旋宇称的测定方法.作为一个例子,引用了J/ψ→γθ(1720),θ(1720)→K⁺K^－过程的计算结果,并对该方法的适用范围进行了探讨.     

J/ψ核吸收新截面难以改变吸收机制的局面

将新发表的J/ψ核吸收截面输入强子和弦级联模型JPCIAE,计算了200AGeV/c的P-A,O-U,S-U和Pb-Pb最小偏畸碰撞中J/ψ压低因子并与实验作比较.结果表明:增大的新截面难以改变核吸收机制不易解释Pb-Pb碰撞J/ψ反常压低局面.     

在J/ψ衰变过程J/ψ→ρρπ中寻找1~(-+)奇特态

利用推广的矩分析和双态耦合处理方法,给出了双态耦合情况下J／ψ衰变过程J／ψ→ρρπ的矩表达式,为在J／ψ衰变过程中寻找并确定1-+奇特态的性质提供了一种可能的途径．     

J1L耦合下原子部分g因子为负值的条件

本文证明了人Ｊ１ｌ耦合下原子部分ｇ因子为负值的条件，并讨论了由此可能产生的影响．