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1.
本文对Fermi-Breit势的自旋交换项、自旋轨道耦合项和张量力项加上适当的收敛因子,连同谐振子禁闭势作为夸克-反夸克相互作用的等效势,对介子谱进行了较严格的计算,所得的结果与实验值基本相符。  相似文献   

2.
重味介子在强子谱研究中扮演着特殊的角色,它是含重夸克的最简单的强子体系.借助相对论性势夸克模型计算了各种D介子基态以及S波低激发态的能量,结果表明除了耦合道引起的质量移动外,赝标重味介子与矢量重味介子的质量分裂可归因于重轻夸克间的自旋耦合能.  相似文献   

3.
在手征SU(3)夸克模型中,用夸克与标量介子九重态和赝标介子九重态场的耦合来描述中长程相互作用,单胶子交换来描述短程相互作用.推广的手征SU(3)夸克模型是在原来手征SU(3)夸克模型的基础上进一步引入了夸克和矢量介子九重态场的耦合,主要由矢量介子交换来描述短程相互作用.在推广手征SU(3)夸克模型下研究了核子-超子相互作用过程,计算了N-Λ和N-Σ相互作用的S波散射相移.通过和手征SU(3)夸克模型的结果比较,发现N-Λ和N-Σ系统的短程相互作用既可以由单胶子交换来描述,也可以由矢量介子交换来描述.  相似文献   

4.
H粒子的结构     
在手征SU(3)夸克模型中,用夸克与标量介子九重态和赝标介子九重态场的耦合来描述中长程相互作用,用单胶子交换来描述短程相互作用.推广的手征SU(3)夸克模型是在原来手征SU(3)夸克模型的基础上进一步引入了夸克和矢量介子九重态场的耦合,主要由矢量介子交换来描述短程相互作用.笔者利用手征SU(3)夸克模型和推广手征SU(3)夸克模型,在两集团组态下研究了H粒子的结构.结果表明, NΞ和∑∑耦合道对H粒子提供比较大的吸引相互作用,两集团之间的夸克交换效应也提供吸引相互作用,它们都有助于H粒子束缚态的形成.另外,通过和手征SU(3)夸克模型的结果比较,发现两种不同的短程相互作用机制对H粒子定性的描述是一致的.  相似文献   

5.
依据QCD基本性质建立的扩展手征SU(3)夸克模型可以很好地解决轻强子方面的问题,本文将该模型应用到重味领域,通过变分法计算自旋为0和1的基态含单个重味夸克介子D、Ds、B、Bs,与自旋为1/2和3/2的基态含单个重味夸克重子ΛQ、ΣQ、ΩQ、ΞQ(其中Q代表c或b夸克)的质量,得到一些初步的结果.当含单个重味夸克介子质量的数值结果基本符合实验值时,实验上已发现的重味重子ΛQ、ΣQ、ΩQ、Σ*Q、Ω*c质量的理论值与相应实验值和其它理论方法的结论也基本符合,除了ΞQ、Ξc*的计算值偏大;实验上未发现的重味重子Ξ*b,Ω*b质量的理论预测值与其它理论方法所得结果偏差不大.同时,简要分析了强子内部的相互作用.  相似文献   

6.
利用推广的带矢量场的手征SUM夸克模型,计算了核子最低负宇称激发态JP=1/2-,3/2-的能量,分析了各种自旋-轨道耦合势对能量劈裂的影响.结果表明,利用矢量介子场耦合可以改进计算结果,但是能级的次序和实验还是相反的.在此基础上进一步考虑其他的自旋-轨道耦合势,可以给出该激发态正确的能级次序.  相似文献   

7.
在假定有质量的组分胶子是介子的构成子之一的基础上,根据Lorentz群与SU(Nc)色群的分析,构造了基态J^p=1^-介质的波函数,分析了基态1^-介子中ρ^±,κ^±,ρ^0,ω和φ介子的磁矩阵与自矩与自旋结构)即夸克,反夸克与组分胶对介子自旋的贡献)得到了关于ρ^±,κ^±介子的磁矩和自旋朗德因子g。的限制条件以及关于基态1^-介子各组成子(夸克,反夸克或组分胶子)所携带的介子自旋的份额r的  相似文献   

8.
伴随着新的D介子不断被发现,奇异介子的族谱也变得丰富起来,利用组份夸克模型研究了强衰变过程D*s1 (2710)→Ds(1968)+π0和D*s1(2710)→D*s(2112)+π0.讨论了D*s1 (2710)这个存在争议的粒子,计算结果支持它由c和(s)组成,属于H类型的双重态(0-,1-),自旋-宇称为JP=1...  相似文献   

9.
手征SU(3)夸克模型和推广手征SU(3)夸克模型的短程相互作用机制完全不同,一种来源于单胶子交换,另一种来源于矢量介子交换.在这两个模型中研究了Ξ*-Ω相互作用,对可能形成(Ξ*Ω)ST=012束缚态的原因进行了探讨.主要分析了这两个模型不同的短程相互作用机制,分析了手征场相互作用及夸克交换效应的影响.计算结果表明,尽管单胶子交换和矢量介子交换机制不同,但在这两个模型中此系统都会形成深束缚态.其主要原因,一是由于σ手征场提供的强吸引相互作用,二是由于它具有特殊的对称性,使夸克交换效应有利于深束缚态的形成.  相似文献   

10.
计算了胶子凝聚与夸克凝聚对于微扰量子色动力学中克与夸克之间的相互作用的非微扰修正的相对论形成对论形式及其非相对论形式展开,由于超出了一般的非相对论近似,一些新形式的自旋-自旋相互作用项、自旋-轨道相互作用项出现在势的表达式中。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
19.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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