首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
在BESⅡ上利用Bhabha,dimu事例确定了BEPC束流对撞中心位置,并以此为初级顶点研究了次级顶点的重建,改进了原有次级顶点重建程序,在此基础上选择 事例,测量了Ks0的寿命,并利用50MJ/ψ数据测量了Ks0的单举质量谱,最后还利用MC研究了Ks0质量的1C拟合.  相似文献   

2.
在BESⅡ上利用Bhabha,dimu事例确定了BEPC束流对撞中心位置,并以此为初级顶点研究了次级顶点的重建,改进了原有次级顶点重建程序,在此基础上选择事例,测量了Ks0的寿命,并利用50MJ/ψ数据测量了Ks0的单举质量谱,最后还利用MC研究了Ks0质量的1C拟合.  相似文献   

3.
在BESⅡ上利用Bhabha,dimu事例确定了BEPC束流对撞中心位置,并以此为初级顶点研究了次级顶点的重建,改进了原有次级顶点重建程序,在此基础上选择J/ψ→k0sk*0→K±ππ+π-事例,测量了K0s的寿命,并利用50MJ/ψ数据测量了K0s的单举质量谱,最后还利用MC研究了K0s质量的1C拟合.  相似文献   

4.
非球面顶点半径和二次常数干涉测量是对二次曲面离轴子孔径在弧矢、子午和中间焦点位置直接干涉测量,拟合得到初级像差系数,并结合化置差计算出顶点曲率半径和二次常数.详细介绍了该方法的基本原理,在此基础上将子孔径中心法线与光轴夹角分解为两个倾角分量α和β引入,改进了现有模型.提出在子孔径对称情况下,可通过调整、控制特定项的泽尼克系数值,消除β分量.进而对新的模型进行了简化,只考虑α分量的影响,给出了仅存在该分量时的非球面顶点半径和二次常数的计算公式,编写了仿真程序.在α=0.03 °,β=0时.直径100 mm,F数为3的抛物面反射镜离轴子孔径的初级像差系数的理论计算和数值仿真结果最大偏差仅为0.0002 λ.研究表明:在子孔径中心法线与光轴的调整存在一定误差时,在弧矢、子午和中间焦点处的初级像差系数特征关系仍然成立.  相似文献   

5.
运用两种方法对L3中心任迹漂移室的顶点位置分辨进行了改进,一种是利用高能量分辨的电子和高动量分辨的μ子测量,限定轻子径迹的曲率半径,对径迹进行重新拟合;另一种是对中心径迹室每半边单元的径迹零位置位移进行校正.结合两种改进方法将轻子的顶点位置分辨由原来的137μm提高到60μm.  相似文献   

6.
史欣  苑长征  班勇 《中国物理 C》2004,28(9):982-985
模拟了北京谱仪(BESⅡ)顶点探测器的触发判选系统,发现对于某些带次级顶点的衰变道,其顶点探测器触发效率较低.并由此对BESⅡ中与效率相关的物理过程作了讨论,给相应的触发设计者提供参考.  相似文献   

7.
韩华  刘婉璐  吴翎燕 《物理学报》2013,62(16):168904-168904
针对复杂网络拓扑结构中模体的存在性, 在传统的顶点度和边聚类系数定义的基础上, 提出了基于模体的顶点度和边度来衡量网络中顶点和边的重要性. 用Rand-ESU算法对不同规模的8个网络进行模体检测, 验证了网络中模体的存在性, 重点分析了Karate网络和Dolphin网络中模体的结构和特征. 用Pearson相关系数衡量基于模体的顶点度与传统顶点度、基于模体的边度与边聚类系数的相关性, 仿真分析结果表明相关性大小与模体种类有关, 基于模体的顶点度和边度是对原定义的一种改进和拓展, 更全面地刻画了顶点和边在网络中的重要性. 关键词: 模体 顶点度 边度 Pearson相关系数  相似文献   

8.
根据Asai,Jimbo,Miwa和Pugai给出的玻色化的A ̄(1)_(n-1)面模型的顶点算子,用面顶点对应关系,得到了与Z_n对称的BelavinR矩阵相关的玻色化顶点算,它们实现了与这种R矩阵对应的Zamolodchikov-Fadeev代数。  相似文献   

9.
提出了一个新的、相对论的、无奇异点的重子顶点形状因子.这个形状因子满足强相互作用过程中,散射振幅从  相似文献   

10.
光学非球面二次曲面常数及顶点曲率的研究   总被引:2,自引:0,他引:2  
受光学非球面制造过程中诸工艺参数的影响,能否保证非球面顶点曲率及二次曲面常数的精度是一个重要问题。基于二次曲面方程,推导出确定光学非球面二次曲面常数k以及顶点曲率半径r的一组算法,并在对一块口径为760mm×200mm标准非球面反射镜的实际测算中进行拟合,经过优化,拟合精度达到Δk=0.015,Δr=0.341mm,从而有效的控制了光学非球面制造过程中的顶点曲率及二次曲面常数的偏差。  相似文献   

11.
In this paper, we construct a new algebra structure 7-twisted atone Lie algebra sl(3,C)[θ] and study its vertex operator representations.  相似文献   

12.
Primary vertex reconstruction is crucial to estimate the beam profile in collision experiments. We study the principle of an iterative process, called the Kalman filter method, and apply it to primary vertex reconstruction at BESⅢ. A Newton procedure to find the zero point of the distance function's gradient is used for primary vertex finding in 3-dimensional space. Results are obtained based on raw data at BESⅢ.  相似文献   

13.
贾晓航  文燕  张谷音 《光学技术》2001,27(4):299-301
主要论述了由焦度仪测量的接触镜实际后顶焦距转化为近轴后顶焦距的可行性问题以及近轴后顶焦距与实际应用相适应性的问题。通过分析和比对一些厂家生产的接触镜光学结构参量 r,n,d后认为 ,由于接触镜球差较大 ,而球差由光学结构参量确定 ,因而同一近轴后顶焦距不同 ,光学结构参量的接触镜实测后顶焦距也不同 ,并且偏差超出了允许范围。所以实际后顶焦距转化为近轴后顶焦距是不恰当的。同时近轴后顶焦距的倒数表征的光焦度与临床验光给出的实际光焦度意义不同 ,因而定义与实际应用不相适应。作者最后提出了接触镜后顶光焦度定义的修正建议  相似文献   

14.
三棱镜顶角成像之剖析及其应用   总被引:2,自引:0,他引:2  
对分光计测三棱镜顶角实验中观察到的顶角成像进行了剖析,并指出它的简单应用。  相似文献   

15.
Kohei Motegi 《Physica A》2011,390(20):3337-3347
Boundary correlation functions of the six and nineteen vertex models on an N×N lattice with domain wall boundary conditions are studied. The general expression of the boundary correlation functions is obtained for the six vertex model by the use of the quantum inverse scattering method. For the nineteen vertex model, the boundary correlation functions are shown to be expressed in terms of those for the six vertex model.  相似文献   

16.
The transverse vector vertex function in momentum space in four-dimensional QED is derived in terms of a set of transverse Ward-Takahashi relations for the vector and the axial-vector vertices in the case of massless fermion. It is demonstrated explicitly that the transverse vector vertex function derived this way to one-loop order leads to the same result as one obtained in perturbation theory. This provides a basic approach to determine the transverse part of basic vertex function from the symmetry relations of the system.  相似文献   

17.
Computer simulations are performed for vertex models which are coarse-grained models for dynamical cellular patterns in two dimensions. By simulating large systems, we obtain conclusive evidence of scaling behavior, that is, a power law for the growth of the average cell size and the scaling properties for the distribution functions of edge number and size of cells. Several versions of the vertex models are obtained by making some approximations for the equation of motion of a vertex, and we compare the statistical properties of the patterns in the scaling regime.  相似文献   

18.
The transverse vector vertex function in momentum space in four-dimensional QED is derived in terms of a set of transverse Ward-Takahashi relations for the vector and the axial-vector vertices in the case of massless fermion.It is demonstrated explicitly that the transverse vector vertex function derived this way to one-loop order leads to the same result as one obtained in perturbation theory. This provides a basic approach to determine the transverse part of basic vertex function from the symmetry relations of the system.  相似文献   

19.
For any finite-dimensional semisimple Lie algebra g, a Z+-graded vertex algebra is construsted on the vacuum representation Vk(g[θ]of g[θ]),which is a one-dimentionM central extension of 8-invariant subspace on the loop algebra Lg=g C((t^1/p)).  相似文献   

20.
We develop the real vertex formalism for the computation of the topological string partition function with D-branes and O-planes at the fixed point locus of an anti-holomorphic involution acting non-trivially on the toric diagram of any local toric Calabi–Yau manifold. Our results cover in particular the real vertex with non-trivial fixed leg. We give a careful derivation of the relevant ingredients using duality with Chern–Simons theory on orbifolds. We show that the real vertex can also be interpreted in terms of a statistical model of symmetric crystal melting. Using this latter connection, we also assess the constant map contribution in Calabi–Yau orientifold models. We find that there are no perturbative contributions beyond one-loop, but a non-trivial sum over non-perturbative sectors, which we compare with the non-perturbative contribution to the closed string expansion.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号