1988 Vol. 12, No. S2

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The Use of Numerical Calculation in the Analysis of Standardless Thick Target PIXE
Fan Qinmin, Zhong Ming
1988, 12(S2): 109-116.
In this paper the numerical calculation is used to correct the characteristic K-X ray intensities measured in the analysis of thick target PIXE for the following matrix effects: the slowing down of protons, the absorption of characteristic X-rays, and the enhancement of X-ray induced X-ray emission in the sample. The efficiency calibrations for PIXE analysis system are made by means of the Monte Cario technique in order to do standardless analysis. Based on this, the PIXE analysis on some self-made standard thick specimens is made. The results are in full agreement with the known values of contents.
A Mean Field Solution of the Fokker-Planck Equation in Lattice Gauge Theories
Xue Shesheng
1988, 12(S2): 117-122.
By decomposing the distribution function of lattice gauge system into product of single link distribution functions, we obtained a mean field solution of the Fokker-Planck equation in Lattice Gauge Theories.
Supersymmetry and The Gauss-Bonnet-Chern Theorem
Yu Yue
1988, 12(S2): 123-130.
The de Rham complex on compact manifolds with boundary must satisfy the elliptic boundary conditions, so their boundary metric must be a product if the condition is to be satisfied by the structure of supersymmetry of field manifolds with boundary in 0 + 1 dimensional space-time. The Gauss-Bonnet-Chern theorem is proved by using the Witten index for a supersymmetric field theory.
The One Pion Exchange Potential at Finite Temperature
Chen Tao, Su Rukeng
1988, 12(S2): 131-136.
By means of the imaginary time Green’s function method, we extend the one pion exchange potential (OPEP) of the nudeon-nucieon interaction to the finite temperature. We sum up ail the bubble diagrams and find that the temperature effect on OPEP is small at the low temperature region but large at the high temperature region. The effective mass of pion field (T) will become imaginary at the critical temperature Tc = 177 MeV. It means that the attractive OPEP will disappear at Tc and the Phase transition takes place.
The Mass Gap in 2 + 1 Dimensional SU(3) Lattice Gauge Theory
Liu Jinming, Zheng Weihong, Guo Shuohong
1988, 12(S2): 137-142.
We present a variational calculation of C = +1 and C = -1 glueball masses in 2 + 1 dimensional SU(3) lattice gauge theory using the Hamiltonian of which the ground state is exactly known. In the range 0 < 1/g2 < 6, we obtained good scaling behavior of am+ = 3.61 g2 and am- = 5.98g2.
Covariant and Quantization of Spinning String in Md × G Space Time
Xu Kaiwen
1988, 12(S2): 143-152.
The BRS charge QB of BRSSS Spinning String model in Md × G space-time is explicitly given. By means of the nilpotency of the BRS charge, the critical dimension and parameters α0R and α0NS can be fixed; and by using the BRS. charge a BRS invariant free open BRSSS string field theory is established, in this model, we find that supersymmetry and BRS invariance can be compatible only when the group G is abeiean. And finally, the massless sector comprising gauge fields with indices of group G is demonstrated.
Influence of the Interference of Odd and Even Waves on Spatial Correlation of Nucleon Pair
Bao Chengguang, Li Xianhui
1988, 12(S2): 153-158.
The effect of the interference of odd and even waves on the spatial correlation of a pair of valent nucleons has been investigated.
Fermion Fields in Soliton Background of Six-dimensional Pure Kaiuza-Klein Theories
Zhang Guangyuan, Cai Weicheng, Li Xinzhou
1988, 12(S2): 159-164.
Dirac wave functions in the six-dimensional Abelian monopoie geometry exhibit a singularity around r = 0, which is in contrast to the five-dimensionai theory. Field equations for fermions in soliton background of a six-dimensional pure Kaluza-Klein theory are derived and illustrated by the spherically symmetric soliton case. Neutral fermion equations are decoupled into ordinary differential equations which agree with those obtained by the nulltetrad formalism in the Schwarzschild black-hole case.
Statistical Model for Partons in Nucleon, EMC Effect and Gluon Distribution Functions of Nucleon Inside Nuclei
Li Zibang, Peng Hongan
1988, 12(S2): 165-174.
Assuming a nucleon as a thermodynamical system composed of partons (quarks and gluons), We discussed its temperature and chemical potential. We also derived the relations between the fractional momentum x distribution of the partons in nucleon and its corresponding statistical distribution. By analogy of the gluons in nucleon with the photons in the black-body, we calculated the effective temperature of the nucleon. Assuming the chemical potential of u, d quark to be the same and setting the reasonable values, we determined the variations of the temperature of nucleon in nucleus by using rescaling scheme. Thus, statistical model could explain the EMC effect quite well. If the chemical potential of gluons is small and negative, the statistical model can also explain the "largeness" of the ratio of the giuon distribution between bounded nucleon and free nucleon in the virtual photoprcxiuction process of J/ψ in the small x region.
Transport Theory Approach to Parton Multiple Scattering in Nuclei---Monte Carlo Simulation
Sa Benhao, Yang Xiazhou, Bai Xixiang
1988, 12(S2): 175-180.
Transport theory approach to the parton multiple hard scattering in nucleus and the corresponding Monte Cario techniques are developed. The difficulty of Q2 dependence is overcome by biased sampling method. As an example, the ratio of π+ production in p (Ep = 400 GeV) + W reaction to p + p reaction is calculated. The calculation result agrees well with the experimental data.
A General Formula of Tune Spread Caused by the Middle-Plane-Asymmetrical Magnetic Field Errors
Zhang Chuang, Chen Siyu
1988, 12(S2): 181-188.
The betatron tune spread caused by magnetic field errors in accelerators is an important parameter. In this paper, an expression of middle-plane-asymmetri-cal magnetic field errors is obtained based on the Maxwell equations, and a general of tune spread is derived starting from the transverse equations of motion.
The Mass Drift Fluctuation and the Shell Effect in Heavy Ion Collisions
Li Junqing, Liu Janye, Zhu Yongtai, Zhu Jieding
1988, 12(S2): 189-198.
The master equation is solved numerically for the mass drift and fluctuation of three reaction channels. The driving potential is calculated by means of the D. Myers' mass formula plus shell and paring corrections. The results indicated that the lack of mass drift in the range of zero to a considerable energy loss in heavy ion collisions could be explained by the transport theory. Due to small mass mobility coefficient the mass does not drift considerably during a short time interval. The effect of the shell structure in the driving potential is obvious for the mass relaxation in the low energy loss region.
The 73Br Decay
Fan Wo, Zhao Zhizheng, Sun Xiuron, Mu Wantong, Ma Jiayu, Yang Weifan, Xie Xiujun, Zhao Lili, Yu Jusheng
1988, 12(S2): 199-208.
The γ-γ coincidence and γ-γ angular correlation measurements of 73Br produced in 64Zn(12C, 2np)73Br reaction have been performed. The energies and relative intensities of the 27 γ-rays are obtained, of which nine lines and three levels were not reported before. The level scheme of 73Br is established. The spin of 90.4 keV level is inferred to be 3/2 or 5/2.
Angular Distributions of Fission-fragments in Interactions of 12C Ions with Various Targets
Liu Guoxing, Chen Keliang, Wang Sufang, Cai Wei
1988, 12(S2): 209-218.
Angular distributions of the fission-fragments were measured for a series of compound nuclei formed in the bombardments of 169Tm, 175Lu, 181Ta, W, Re, Pt, 197Au, Pb and 209Bi by 12C ions with mica nuclear track detectors and gold surface barrier silicon detector. All the measured angular distributions can be fitted satisfactorily by the theoretical formula based on the statistical saddle point mcxiei. The trend of variation for K02 with increasing excitation energy E* was given at various ranges of fissiiity parameter Z2/A in this work.