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1.
In this paper we examine the electroweak interference effects related to the polarized photon structure functions making use of the results of the ref.[2]. The effects provide the probability of a further test of the G-W-S model and may lead to a deep understanding to the photon structure functions.  相似文献   

2.
Experimental data from the PEP-II B-factory at 10.6 GeV center-of-mass (c.m.) energy, obtained via initial-state radiation (ISR) with the BABAR detector, are presented. The cross sections for many hadronic processes have been measured from the production threshold to 4-5 GeV of the e^+e^- c.m. energy. The obtained data allow to study a number of intermediate states and determine the parameters of known resonances and their branching fractions. The exclusive cross section for some number of hadronic sub-processes are presented.  相似文献   

3.
In the structure function approach,we calculate the threshold behaviours for e++e→τ+,which including QED radiative corrections from initial correction,vacuum polarization effect,Coulomb effect and final state correction.This theoretical prediction for threshold behaviours of τ-pair production is useful for BES new measurement of lepton τ mass.  相似文献   

4.
本文指出, 夸克组合中快度近关联与QCD的要求一致, 并与慢强子先产生原则一起, 完全确定夸克组合律, 并自动排除重子偶素的产生. 给出了N对夸克随机组成介子、重子与反重子的计算公式. 把它用于e+e湮灭, 根本不需另引入双夸克对的真空激发等假定, 即自然解释了重子的显著产生.  相似文献   

5.
在这篇文章中,我们用[2]中的结果讨论了与极化光子结构函数相关的电弱干涉效应,这个效应提供了对G-W-s(格拉肖-温伯格-萨拉姆)模型作进一步检验的可能并且导致对光子结构函数的更深入的了解。  相似文献   

6.
本文分析了e+e 湮没中多重数的实验分布, 指出可能是夸克数目服从四动量守恒限制下的Poisson分布, 加上组合过程影响的结果. 并利用一种在其他方面取得明显成功的夸克组合律作了计算, 得到与实验符合的结果. 还对轻夸克jet作了单独讨论.  相似文献   

7.
Using the BES data collected at √S=4.03GeV.the QED processes of e+e→e+e+μ have been studied. Our measurements agree with the QED prediction,and luminosities obtained from these two final states are compatible at a level of 4%.The total integrated luminosity of 23.1pb-1 was given for all data collected at this energy region from the calculation.  相似文献   

8.
The comparison of two fragmentation schemes used in the analysis of e+e annihilation are presented in this paper.It is found that the independent fragmentation assumption is strongly disfavored by the data of the final particle multiplicities,and the string fragmentation assumption agrees with experiments.  相似文献   

9.
The probability of Color Rearrangement at partonic level in e+e→W+W→h,s process is studied using the Color Effective Hamiltonian. The comparison between our results and those of Gutafson and Sjostrand et al. is also given. It is found that this probability cannot be neglected, and it is pointed out that to investigate the Color Rearrangements, the hadronization models should be developped and improved.  相似文献   

10.
Following perturbative QCD theory, the two-jet and three-jet angular distributions in polarized e+e annihilation is computed using the dimensional regularization scheme. The azimuthal inhomogeneity caused by the polarization is discussed. We also compute the exact formulae of dependence on ε´,δ to the second order and discuss the correction to G.Sterman and S.Weinberg's result.  相似文献   

11.
本文应用复合场论微扰展开式和相对论的 B-S 近似波函数,计算了类似于 Primakoff 效应的光生相对论的(e+e-),(μ+μ-)仲原子的过程.结果与通常点模型的计算结果不同,这里多得出了一个新的形状因子.这表明在通常的Primakoff 效应中也将存在类似的修正.  相似文献   

12.
本文将带区近似法推广到光子-核子散射过程。由t道弹性么正条件导出了光子-核子散射的带区谱函数和s道散射振幅的吸收部分,由此计算了光生π介子的非弹性截面,并与实验作了比较。  相似文献   

13.
From the simple physical picture of quark combination model, we obtain the generate probabilities of various particles and relative ration in e+e→q0q0→h′s process, and find that the relationship between the ration of strange hadron to unstrange hadron γ and the strangeness suppression factor λ. Our results can be used to explain particle ration enhancement observed in experiments without assumption of strangeness suppression factor enhancement.  相似文献   

14.
We report the results of a search for the semileptonic decays D+→e+ν,D+→Kπ+e+ν,D0→Ke+ν and D0→Kμ+ν using the BES detector at the BEPC e+e Collider. Using a data sample of 22.3pb-1 collected at the center of mass energy s=4.03GeV, we select 2472±87D 0 tag DX and 7628±149D 0 tag DX singly tagged D events, where the X could be γ, π 0 and/or π±. Based on the method of "combined D+and D0 single and double tags", we determine that 2471±218 D+X and 7629±251 D0 X are contained in the recoil side of the singly tagged neutral and charged D mesons, respectively. No events for the 4 semileptonic decay modes are observed in the recoil side of the tagged D mesons. The 90% confidence level upper limits of B(D+→e+ν)<1.38%,B(D+→Kπ+e+ν)<2.01%,B(D0→Ke+ν)<0.53% and B(D0→Kμ+ν)<0.53% are determined from the search for the semileptonic decays of D+ and D0.  相似文献   

15.
利用结构函数方法,足够精确地给出了在e+e对撞过程中考虑了各种QED辐射修正效应后的τ轻子产生的阈行为解析表达式(这里包括了始态辐射修正、真空极化效应、库仑效应和终态修正效应等),这个阈行为用来为BES测量τ轻子的质量值.  相似文献   

16.
本文利用e+e→重夸克jets中, 可分辨电磁激发与强作用产生的夸克的优点, 对后者的产生规律作了研究, 发现它产生的夸克对数满足一种简单普适规律, 由此算出的i>多重数分布、前后关联等等都和实验符合、本文介绍了与的比较.  相似文献   

17.
We report a measurement of the absolutely inclusive semileptonic branching fractions of D and D0 mesons, using a data sample of 22.3pb-1 collected with BES detector at BEPC e+e Collider at s=4.03GeV and based on the method of "combinative D+ and D0 single and double tags". The measured values of the branching fractions for D→eX and D0→eX are (21.8±8.5±4.2)% and (8.9±3.0±1,6)%, respectively. The measured ratio of the branching fractions is BF(D→eX)/BF(D0→eX)=2.4±1.7±0.8.  相似文献   

18.
We show that the near correlation in rapidity is consistent with the requirements of QCD, and completely determines the combination rule of quarks. We give the formulae for calculating yields of mesons, baryons and antibaryons, which are produced by a stochastic accumulation of quarks with similar rapidities. Using it to e+e annihilation, the observation of recently unexpected copious production of baryons is explained naturally.  相似文献   

19.
A study of the dynamical fluctuation properties at various c.m. energies in e+e collisions is performed using the Monte Carlo method. The results suggest that, after the normalized factorial moments of 3-dimensional phase space are analyzed using an isotropical phase space partition, the NFM describing non-linear dynamical properties show a power-law scaling, i.e., the dynamical fluctuations in higher dimensional phase space are isotropic. For c.m. energies √s≤80 GeV, the scaling exponents φq increase rapidly with the c.m. energy and for c.m. energies √s>80GeV, the φq gradually saturate.  相似文献   

20.
Based on the electroweak unified standard model,the probability Pi for the production of i-quark jet (i=u,d,c and b)in e+e annihilation has been studied.The probability Pi is a function of energy s.The calculated component ratios of Pu:Pd:Ps:Pc:Pb are 4:1:1:4:1 for s<30GeV.7:9:9:7:9 for s=mz=91.16GeV and 1:1:1:1:1 for s=78 and 117GeV,respectively.Using Pc and Pb,we whave calculated the yields of charmed and beautiful mesons in e+e annihilation at s=10—178GeV.  相似文献   

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