PGBs对高能e~＋e~－湮没产生顶夸克对的单圈量子效应

在一代Ｔｅｃｈｎｉｃｏｌｏｒ（ＴＣ）模型中计算了ＰＧＢｓ（ＰｓｅｕｄｏＧｏｌｄｅｎｓｔｏｎｅＢｏｓｏｎｓ）对高能ｅ＋ｅ－→ｔｔ过程的单圈量子效应．给出了重整化的形状因子和矩阵元．计算了ＰＧＢｓ对总截面前后不对称参数ＡＦＢ和左右不对称参数ＡＬＲ的虚贡献，结果表明选取适当的参数值，新物理对以上可测量的贡献最大分别可达：－１２．３％、－３．３％和－１１．７％．在下一代对撞机上这一理论结果能为ＴＣ理论打开实验的窗口．同样的计算表明ＰＧＢｓ对ｅ＋ｅ－→ｂｂ过程的单圈贡献小于－１．０％．     

关于Bose-Einstein凝聚(续)

关于Ｂｏｓｅ－Ｅｉｎｓｔｅｉｎ凝聚（续）张礼（清华大学现代应用物理系，北京１０００８４）（收稿日期：１９９７－０７－１６）４弱相互作用Ｂｏｓｅ气体：均匀凝聚体ＢＥＣ所以在粒子没有相互作用时发生，是全同玻色子体系波函数对称性的后果．在这个意义上可以称之...     

评述文章扫描(英文)

１ＴｈｅｏｒｙｏｆＢｏｓｅ－Ｅｉｎｓｔｅｉｎｃｏｎｄｅｎｓａｔｉｏｎｉｎｔｒａｐｐｅｄｇａｓｅｓ（ＦｒａｎｃｏＤａｌｆｏｖｏ,ＳｔｅｆａｎｏＧｉｏｒｇｉｎｉ,ＬｅｖＰ．Ｐｉｔａｅｖｓｋｉｉｅｔａｌ．Ｒｅｖ．Ｍｏｄ．Ｐｈｙｓ．,１９９９,７１：４６３—５１２）２Ｔｏｐ－ｑｕａｒｋｃｏｎｄｅｎｓａｔｉｏｎ（Ｇ．Ｃｖｅｔｉｃ．Ｒｅｖ．Ｍｏｄ．Ｐｈｙｓ．,１９９９,７１：５１３—５７４）３ＰｒｅｃｉｓｉｏｎｔｅｓｔｓｏｆｔｈｅｅｌｅｃｔｒｏｗｅａｋｉｎｔｅｒａｃｔｉｏｎａｔｔｈｅＺｐｏｌｅ（Ｍ．Ｍａｒｔ…     

服从Bose—Einstein统计多原子体系的共振荧光

文中给出了计算服从Ｂｏｓｅ－Ｅｉｎｓｔｅｉｎ多原子体系共振荧光的方法。因为满足Ｂｏｓｅ－Ｅｉｎｓｔｅｉｎ统计，这多 原子体系的波函数应具有排列对称。文中还较详细地讨论了一些有关问题。     

关于Bose-Einstein凝聚

自１９９５年气体原子Ｂｏｓｅ－Ｅｉｎｓｔｅｉｎ凝聚（以下简称ＢＥＣ）发现以来，新成果不断涌现．文献［１］叙述了气体原子ＢＥＣ实验实现的物理基础以及发现过程．本文着重阐述理论的基础概念，特别是讨论ＢＥＣ的本质，即对称的自发破缺及相位的相干性，并介绍弱相互作用Ｂｏｓｅ气体理论．本文供从事基础物理教学的老师参考，有一定量子力学、统计物理知识的同学也可以阅读．     

解有排斥相互作用中性原子的Bose—Einstein凝聚的一般方法

提出了解有排斥相互作用情形中性原子 Ｂｏｓｅ Ｅｉｎｓｔｅｉｎ 凝聚的一般方法．并应用于势场 Ｖ＝ ０ ,但有排斥相互作用ｇ ＞ ０ 情形的中性原子气体,求得其解析解,进行了 Ｂｏｓｅ Ｅｉｎｓｔｅｉｎ 凝聚计算．     

双Λ超核_(ΛΛ)~6He和_(ΛΛ)~(10)Be的少体动力学

在α集团模型下，完成了对６ΛΛＨｅ和１０ΛΛＢｅ的变分计算，并研究了各种Λα势和ΛΛ势，借助拟合６ΛΛＨｅ数据所得的修正Λα势与统一的ΛΛ势，获得了超核６ΛΛＨｅ，９ΛＢｅ和１０ΛΛＢｅ的自洽描述。此外，对上述超核的基态结构和粒子关联也作了研究和分析。相互作用矩阵元利用著名的Ｔａｌｍｉ－Ｍｏｓｈｉｎｓｋｙ变换计算     

静高压下非晶（Fe0.09,Mo0.01）74Si9B13合金晶化过程的热力学研究

在６００－９３０Ｋ，常压到７ＧＰａ的范围内，对非晶（Ｆｅ０．９９，Ｍｏ０．０１）７８Ｓｉ９Ｂ１３合金等温等压退火３０ｍｉｎ。实验表明；其晶化产物α－Ｆｅ（Ｍｏ，Ｓｉ）Ｆｅ３Ｂ和Ｆｅ２Ｂ相的析出与所加压力密切相关。压力使非晶（Ｆｅ０．９９Ｍｏ０．０１）７８Ｓｉ９Ｂ１３合金的晶化温度和亚稳Ｆｅ３Ｂ相的析出温度下降，在一定的压力和温度下，亚稳Ｆｅ３Ｂ相半向稳定Ｆｅ２Ｂ相转变其转变温度随压力而变化。     

顶色辅助的多标度人工色理论对稀有过程e~ e~-→s的单圈效应

讨论了顶色辅助的多标度人工色理论预言的赝标哥尔斯通玻色子（ｔｅｃｈ－ ｎｉｐｉｏｎｓ,ｔｏｐ－ｐｉｏｕｓ）对稀有过程ｅ＋ｅ－→ｂｓ的单圈效应,计算了该过程在ＬＥＰⅡ上 的产生截面,得到较标准模型预言值要大一个数量级的数值结果．并进一步讨 论了在Ｂ介子工厂上探测此稀有过程的可能性．     

关于Bose—Einstein凝聚

自１９９５年气体原子Ｂｏｓｅ－Ｅｉｎｓｔｅｉｎ凝聚发现以来，新成果不断涌现。文献「１」叙述了气体原子ＢＥＣ实验实现的物理基础以上发现过程。     

Defects in the discrete non-linear Schrödinger model

The discrete non-linear Schrödinger (NLS) model in the presence of an integrable defect is examined. The problem is viewed from a purely algebraic point of view, starting from the fundamental algebraic relations that rule the model. The first charges in involution are explicitly constructed, as well as the corresponding Lax pairs. These lead to sets of difference equations, which include particular terms corresponding to the impurity point. A first glimpse regarding the corresponding continuum limit is also provided.     

Fermi Resonances and Vibrational Spectrum of a Polyatomic Molecule XY4: an Algebraic Approach

A U(2) algebraic model is introduced for the spectrum of a molecule XY₄, where the interactions between the stretch and bend modes are described by T_d symmetric Fermi resonance terms. The presented algebraic model in a limit corresponds to another model in recent literature. The vibrational spectrum of methane (CH₄) measured recently with modern spectroscopy techniques is employed to test those models. The obtained standard deviation between the observed and the calculated vibrational energy levels in the algebraic model is smaller than that in the corresponding model.     

SYMMETRIES OF CONFORMAL TRANSFORMATION FOR SPECTRAL PARAMETER

The symmetry of O(3) non-linear sigma model under a dual transformation is discussed and the origin of the transformation of generating functions is explored;Existence of the infinite dimensional symmetries is confirmed.We obtain the infinite dimensional Lie algebraic structure of the basic fields and the semi-product algebraic relation of the two kinds of algebra.The corresponding Bianchi-Backlund transformations are given.     

Dynamical group model of a spin density wave system

We obtain the dynamical group for a mean field quasi-one-dimensional model of an interacting many electron system exhibiting spin density waves. The corresponding Lie algebra is a sub-algebra of su(8); we use it to obtain the spectrum and define the corresponding order parameters. The algebraic treatment is extended to cover the presence of an external magnetic field.     

Algebraic Model Applied to Vibrations in the Electronic Ground State of NO2

An algebraic model of boson realization and a corresponding q-deformed model are used to study tile vibrations in the electronic ground state of NO₂. The two models are applied to fit the 142 vibrational band origins below 9000 cm^-1 with the standard deviations 3.23 cm^-1 and 3.12 cm^-1, respectively.     

Symmetric and Non-Symmetric Bases of Quantum Integrable Particle Systems with Long-Range Interactions

We study in an algebraic manner the symmetric basis of the Calogero model and the non-symmetric basis of the corresponding Calogero model with distinguishable particles. The Rodrigues formulas are presented for the polynomial parts of both bases. The square norm of the non-symmetric basis is evaluated. Symmetrization of the non-symmetric basis reproduces the symmetric basis and enables us to calculate its square norm.     

Elliptic Gaudin models and elliptic KZ equations

The Gaudin models based on the face-type elliptic quantum groups and the XYZ Gaudin models are studied. The Gaudin model Hamiltonians are constructed and are diagonalized by using the algebraic Bethe ansatz method. The corresponding face-type Knizhnik–Zamolodchikov equations and their solutions are given.     

The algebraic Bethe ansatz for the Osp(2|2) model with open boundary conditions

We obtain four different diagonal reflecting matrices by solving the reflection equation of the Osp(2|2) model. At the same time, we solve the model with open boundary condition by using the algebraic Bethe ansatz. The procedure of constructing the multi-particle state and achieving the eigenvalue of the transfer matrix and corresponding Bethe equations is presented in detail.     

一类三维等代数结构面剖分下的代数多重网格算法

对一类等代数结构面的三维非结构网格剖分,针对光滑变系数和各向异性系数的偏微分方程,给出两种非结构代数多重网格算法,数值试验表明算法的有效性和健壮性.