1990 Vol. 14, No. S1

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The Muon Counter in the Beijing Spectrometer
Zhu Yongsheng, Zhang Liangsheng, Gao Wenxiu, Zhang Yingping, Zhao Pingde, Zhang Jiawen, Li Fang, Chen Lejun, Xu Zhiqing
1990, 14(S1): 1-10.
The arrangement and design performance of the muon identifier in the Beijing Spectrometer (BES) are described. The gas gain, plateau feature, drift time, detection efficiency, charge division for the hit location and other characteristics of the muon counter modules have been measured.
On the Nature of the Medium Lifetime Component of Positron Annihilation in a Teflon Polymer
Wang Shuying, Zhang Tianbao, Shentu Yanming, Wang Haidong, Yang Guangming
1990, 14(S1): 11-18.
The nature of the medium lifetime component of positron annihilation in a Teflon (PTFE) polymer has been investigated by usiiig a recently developed Time Selecting γ Energy Spectrometer with and without a magnetic field. It has been assigned to o-Ps quenching annihilation, just the same as the longest lifetime component.
The Semi-Inclusive Distributions and the Rapidity Dependence of Multiplicity Distributions in e+e- Annihilation into Two Jets
Lai Xiaoping, Xie Qiubing, Fang Haiping
1990, 14(S1): 19-26.
Based on the proposed model of e+e- annihilation into two jets proposed, we further assume that the rapidity distribution of quarks is a uniform one with the constraint of four-momentum conservation. The semi-inclusive rapidity distributions and the multiplicity distributions in different rapidity intervals for light quark jets are calculated by the Monte Carlo method. After discussing their behavior, the results are compared with the data for average jets.
Inhomogeneous Differential Realization, Boson-Fermion Realization of Lie Superalgebra B(0,1) and its Representations
Fu Hongchen
1990, 14(S1): 27-37.
The differential realization of Lie superalgebra B(0,1) on the space of inhomogeneous polynomials (called inhomogeneous differential realization), and the corresponding inhomogeneous Boson-Fermion realization are studied. By making use of the inhomogeneous Boson-Fermion realization, a new kind of indecomposable and irreducible representation of Lie superalgebra B(0,1) is studied on the universal enveloping algebra of Heisenberg-Weyl superalgebra, its subspaces and its quotient spaces; AH the finite dimensional irreducible representations of Lie superalgebra B(0,1) are naturally obtained as special cases.
The Fragmentation Mechanism in e+e- Annihilation
Liu Ximing
1990, 14(S1): 39-44.
A comparison of two different fragmentation schemes in e+e- annihilation is presented in this paper. After further calculations of the average number of various final hadrons and comparison with experiments, we find that the independent fragmentation scheme is in contradiction with the data whereas the string fragmentation assumption fits the data well.
Calculation of a Fixed Length Fundamental SU(2) Higgs Model
Zheng Xite, Liu Beishu
1990, 14(S1): 45-52.
The phase diagram of the system of SU(2) gauge field coupled with the fixed length Higgs field in the fundamental representation has been calculated analytically on the lattice by the variational-cumulant expansion method to the third order approximation. The method for determining the variational parameters has been improved by using the expression of the free energy to the second order approximation. Thus the calculated phase diagram is in good agreement with the Monte Carlo estimation and the order of the phase transition is clearly determined in the third order approximation.
Two-Higgs-Doublet Model and the Splitting of tt p-States
Ding Yibing, Qin Danhua, Chao Kuangta
1990, 14(S1): 53-57.
The existence of two Higgs-doublets alters the splittings of 1p and 2p tt states and reduces the ratios of the splittings, R. Their fine measurement will be helpful to clarify the existence of Higgs particles.
Investigation of the Nuclear Shadowing Effect in the Small x Region
Zhong Chasheng, Shen hongqing, Shen Jianping, Li Guangiie
1990, 14(S1): 59-63.
In this paper, we analyse the spatially overlapping behaviour of the sea quarks of neighboring nucleons in nuclei in the small x region and give a relation between the nuclear shadowing factor R(x, Q2, A) and the spatially overlapping factor ΔVA(x)/VA(x). By using this nuclear shadowing factor R(x, Q2, A), we calculate the ratios of the average nuclear structure function and obtain 12C, 63Cu and 116Sn, to the deuteron structure function and obtain nuclei which yield a better agreement between the calculated results and the experimental data.
A Solvable 1 + 1 Dimensional U(l) gauge model
Zheng Bo, Guo Shuohong
1990, 14(S1): 65-69.
A 1+1 dimensional U(1) gauge model is proposed and the spectrum with the energy eigenstates represented in terms of fermion operators is exactly solved.
Berry's Phase Factor in a Moving Reference Frame and Its Observable Effects in Physics
Sun Changpu, Zhang Linzhi
1990, 14(S1): 71-81.
In the non-relativistic case the properties of the adiabatic approximation solution of the Schrödinger equation in the moving reference frame and the corresponding Berry's phase factor are discussed in this paper. Translation and rotation reference frames are analyzed in detail. These discussions demonstrate that the appearance of the Berry's phase factor depends on the choice of the reference frame. For the Bitter and Dubbers' experiment about neutron polarization, which concerns the translation reference frame, we not only obtain the result of the zeroth-order approximation in agreement with the experiment, but also do further analysis for the high-order effects that may appear when the adiabatic condition is broken.
Choice of Single Particle Potentials in a Manv-Bodv calcu-lation-Hartree-Fock and Mass Operator Potential
Yao Yujie, Jing Xiaogong, Zhao Guoquan, Yang Shande, Wu Shishu
1990, 14(S1): 83-91.
A detailed comparison between the Hartree-Fock (HF) and the mass operator (M) potential is made by means of a solvable three-level model. It is found that in a quite large region of force parameters (FPR) the M potential gives a much better result than the HF potential and at certain points in FPR the HF result undergoes a sudden jump while the M result varies smoothly. The convergence behavior of the perturbation expansion of M has also been studied.
Excitation Functions for 16O-lnduced Reaction on 115In
Sun Tongyu, Li Wenxin, Wu Dingqing, Wang Sufang, Xu Shuwei, Zhao Lili, Guo Yingxiang, Sun Xiurong
1990, 14(S1): 93-97.
Excitation functions for 21 products of the reaction induced by 16O on 115In have been determined in an energy region between 51 and 97 MeV using nuclear chemistry techniques. The experimental results have been compared with those calculated using Alice code and Monte-Carlo simulation.
Energy Calibration for a Plastic Scintillator Beta-Detector Telescope
Xu Shuwei, Liu Manqing
1990, 14(S1): 101-104.
A plastic scintillator beta-detector telescope has been built and calibrated. Tests show that the uncertainty of linear energy calibration in the range of endpoint energy between 0.7 and 6.1 MeV for both β- and β+-emitters is 35 keV.