Color Rearrangement in e+e－→W+W－→h's Process

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.     

A Rigorous Calculation for the Radiator in e+e－ Process

Using the precise expression of electron,positron distribution function we obtained earlier,we derive the rigorous analytical expression of radiator in e⁺e^－ collision process.This series expression converges rapidly to the precise result required.The comparison with existing approximate expression is also given.Our result benefits the precice calculation for the radiative corrections in e⁺e^－ collision processess.     

高能e++e－→e++e－+强子过程中的电弱干涉效应

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.     

A Study of the Processes of e+e－→e+e－,μ+μ－ at Large Angle and Measured Luminosities

Using the BES data collected at √S=4.03GeV.the QED processes of e⁺e^－→e⁺e^－,μ⁺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.     

ELECTROWEAK INTERFERENCE EFFECTS IN THE HIGH ENERGY e++e－→e++e－+ HADRONS PROCESSES

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.     

Analytic Approximation for Process e++e－→τ++τ－ Cross Section Near Threshold

In the structure function approach,we calculate the threshold behaviours for e⁺+e^－→τ⁺+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.     

Strangeness Suppression in e+e－ Light Flavour Jets

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.     

Helicity Formalism of the Angular Distributions for the Process e++e－→J/ψ→V+X,X→3P

The helicity formalism of the angular distributions for the process e⁺+e^－→J/ψ→V+X,X→P₁+P₂+P₃(V and stand for vr and psealar meson, respectvely) are given in this paper. It provides the theical formula for determining the spin and parity of the intermediate state X of the above process.     

Search for the Decays D+→φe+ν,D+→φK－π+e+ν,D0→φK－e+νand D0→φK－μ+ν

We report the results of a search for the semileptonic decays D⁺→e⁺ν,D⁺→K^－π⁺e⁺ν,D⁰→K^－e⁺ν and D⁰→K^－μ⁺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⁺→K^－π⁺e⁺ν)<2.01%,B(D⁰→K^－e⁺ν)<0.53% and B(D⁰→K^－μ⁺ν)<0.53% are determined from the search for the semileptonic decays of D⁺ and D⁰.     

e+e－湮灭中的夸克组合律

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.     

THE FRAGMENTATION SCHEMES IN e+e－ ANNIHILATION

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.     

Influence of Interference Terms on Probability of Color Connections among Partons in e+e－→qq+ng Process

Large N_c approximation is adopted in popular e⁺e^－ event generators where the production probability of singlet chain states is 100% and that of color separate states is 0. In the real world N_c=3, we investigate the origin and character of color and kinematics aspects in interference terms. We find that the production probability of color singlet chain states decreases from 83%, 77% to 67%, 58% for qq+2g and qq+3g system respectively after considering the interference terms. Especially, the production probability of color separate states increases to twice of that without interference terms for qq+2g. Hence when n is larger, we can expect that the production probability of singlet chain states will be far less than 1 and that of color separate states will significantly increase when n is larger.     

高能e+e－→两喷注时的夸克产生律

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.     

QCD JET IN POLARIZED e+e－ ANNIHILATION

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.     

Charmless Hadronic Decays B→VV in the Topcolor-Assisted Technicolor Model

Based. On the effective Hamiltonian with the generalized factorization approach, we calculate the branchingratios and CP asymmetries of B → VV decays in the Topcolor-assisted Technicolor (TC2) model. Within the consideredparameter space we find that: (a) for the penguin-dominated B → K* φ and K*0 φ decays, the new physics enhancementsto the branching ratios are around 40%; (b) the measured branching ratios of B →K* φ and K*0φ decays prefer therange of 3 Neffc 5; (c) the SM and TC2 model predictions for the branching ratio B(B →ρ ρ0) are only about halfof the Belle‘s measurement; and (d) for most B → VV decays, the new physics corrections on their CP asymmetries are generally small or moderate in magnitude and insensitive to the variation of mπ and Neffc.     

Scale for the Production of Jets in High Energy e+e－ Collisions

The scale for visible jets produced in e⁺e^－ Collisions is studied in some details using Monte Carlo method. It is demonstrated, based on the historical fact that the 3-jet events were firstly observed in e+ e- experiments at √S=17—30GeV,and the relative transverse momentum for visible jets is in the region k_t,～5—10GeV/c. It is further shown, using a concrete example, that the number of jets in an event could be correctly evaluated only when k_t is in this region. The dynamical fluctuations inside jets determined through different values of k_t are compared carefully. It turns out that only when k_t,～5—10GeV/c the dynamical fluctuations inside jets will possess the best anomalous scaling property. The relation between the scale 5-10GeV/c of visible jets and the scale 1-2GeV of perturbative QCD is discussed.     

Energy dependence of non-linear dynamical features in e+e－ collisions

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 φ_q increase rapidly with the c.m. energy and for c.m. energies √s>80GeV, the φ_q gradually saturate.     

RAPIDITY DISTRIBUTION AND BARYON-ANTIBARYON CORRELATIONS IN e+e－→TWO JET EVENTS

We extend our model by introducing explicitly the energy-momentum of quarks.By using the Monte-Carlo method,the rapidity distribution in light jet events is calculated.Agreement with experiment data is good.The baryon-antibaryon correlations in rapidity,open angle,azimuthal angle are also given,which are in agreement with experiment on the whole.     

Study of the e+ e－ to hadrons via ISR at BABAR

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.     

e+e－湮没过程的多重数分布

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.