1991 Vol. 15, No. 8

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The Study of Basic Characteristics of the Proportional Inclined Chamber
WANG Jian-Chun, MA Wen-Gan, XU Zi-Zong, CHEN Hong-Fang, LIN Zi-Rong
1991, 15(8): 673-679.
We analyzed the data from both beam test and theoretical simulation of the proportional inclined chamber.A detailed study of basic characteristics of the chamber has been done.It shows that the position accuracy in the wire plane along the direction perpendicular to anode wires is better than 200μm.and the theoretical simulation can explain the experimental results very well.
The Performance Improvement and Its Application of Beijing Proton Linac
WANG Shu-Hong, ZHOU Qing-Yi, WAN Heng-Fang, ZHANG Hua-Shun, XIAO Lian-Rong, XUE Jing-Xuan, JIN Qing-Shou, ZHANG Cheng-Xian, LUO Zi-Hua, KE Xue-Yao, LIU Dian-Kui, HE Wei-Ning
1991, 15(8): 680-688.
The main characteristics,performance improvement,status,and its application of Beijing Proton Linac are described in this paper.
Vextex Corrections and one σ Exchange Potential at Finite Temperature
ZHENG Guo-Tong, SU Ru-Keng
1991, 15(8): 689-694.
By using the imaginary-time Green's function method in finite temperature field theory,we calculate the effects of the three-line vertex function on finite temperature one σ-meson exchange potential.It is found that the finite temperature coupling constant of the sigma-nucleon interaction decreases as the temperature increases,it approaches zero when temperature arrives at 210MeV.This result is quite similar to that the temperature dependence of coupling constant given by Nambu-Jona-Lasinia model at the quark level.
A Rigorous Method for Calculating the Casimir Effect
NI Guang-Jiong, ZHANG Min, GONG Jia-Wen
1991, 15(8): 695-700.
Using the Plana summation formula in complex variable function theory,we have calculated the Casimir energy related to the zero-point fluctuations of electromagnetic fields in three dimensional space without introducing any cutoff parameter or function.The finite analytical expression obtained coincides precisely with the known experimental and theoretical results.The Casimir effects in high dimensional space and relevant to massive scalar field are also discussed.
Affine Toda Fields as Restriced WZNW Model
HOU Bo-Yu, ZHAO Liu, YANG Huan-Xiong
1991, 15(8): 701-710.
The Sine-Gordon equation is derived from the conformally invariant WZNW model by imposing constraints.The action,equation of motion,canonical equal-time Poisson braket and energy-momentum tensor of S.G.E. are obtained,and the absence of conformal invariance and the complete integrability of S.G.E. are explained.The restricted WZNW model is related to the nonlinear sigma model.In addition,the SL(n,R) affine Toda fields and the SL(2,R) conformal affine Toda fields are also derived from the restricted WZNW model.
Conditional Entropy and Mutual Information in Random Cascading Processes
WU Yuan-Fang, LIU Lian-Shou
1991, 15(8): 711-714.
The conditional entropy and mutual information of two neighboring generations of division are proposed to use as characteristics in analyzing the random cascading mechanism in multiparticle production.It is shown that these characteristics are effective in examining the exsistence and property of self-similar cascading.
The πN→ηN Reactions near Threshold and η-N Scatterings
JIANG Huan-Qing, WANG Wei-Wei
1991, 15(8): 715-719.
The N*(1535) model is proposed for pionic η- production reactions.The πN→ηN reaction cross sections near threshold and the S-wave η-N scattering length are calculated and compared with the experimental data and other theoretical calculations.
The Semiclassical Study of Nuclear High Spin States
SHEN Xiao-Yan, HU Ji-Min
1991, 15(8): 720-729.
Nuclear high spin states are studied in the extended Thomas-Fermi approximation.Explicit formula for rotational energy and various corrections are given.Concrete calculations are performed for three typical nuclei:116Sn,158Yb and 240Pu.Qualitatively,the results are similar to that of liquid drop model.Quantum corrections to rotational energy (besides shell corrections) cannot be neglected in a quantitative study.
α-Nucleus Scattering at High Energies
SHEN Jun-Feng, ZHANG Yu-Shun
1991, 15(8): 730-736.
In this paper ,the differential cross sections of the elastic and inelastic scattering of alpha-particle of energy 1.37GeV on the 2+ and 3 excited states of 12C and Ca isotopes are calculated by the method of the inelastic two-composite-particle system scattering theory at high energy.The results are in agreement with experimental data.The importance of the virtual excitation in calculating the differential cross section of the elastic is descussed.
A Three-Body Model of 11Li,14Be and 17B
REN Zhong-Zhou, XU Gong-Ou
1991, 15(8): 737-741.
The nuclei 11Li,14Be and 17B are considered as three-body systems composed of the N=2Z core and two outside neutrons.The core-neutron and neutronneutron interactions are assumed to be the attractive exponential potentials.It has been shown that the three-body system can have a bound state although any two constituents of the system cannot have a bound state. The experimental data of the binding energy and extraordinarily large matter root-mean-square radius can be explained in the frame of the three-body model.
The Strong Coupling SU(3) Limit in IBM4
LI Guang-Hua, SUN Hong-Zhou, HAN Qi-Zhi, LI Xian-Yin
1991, 15(8): 742-747.
When the IBM is generalized and used to the case of light nuclei,it is called IBM4.In this paper,for the following group chain of the IBM4 U(36)U6(sd)×U6(ST) SU3(sd)×SU3(S)×SU3(T) SU3(sdS)×SU3(T)× O3(J)× O3(T) the reduction rules,typical energy spectra and E2 transitions are discussed.Using this strong coupling SU(3) limit,the nuclei in sd shell are classified.
About Three-Body Exit Channel in the Reaction 12C+16O at EL(16O)=56MeV
KONG Xiang-Jing, LI Pan-Lin
1991, 15(8): 748-753.
Three-body exit channel in the reaction 12C+16O at 56MeV has been studied by using measurement of the coincidence between the two changed particles.The projected spectra of the coinsidence between the two α-particles shows that the channel α+24Mg is the main intermediate process of three-body exit channel α12+20Ne in the reaction 12C+16O at 56MeV.The analysis of theoretical calculation showed that the sum of sequential decay and statistical break-up fit the experimental spectra satisfactorily.
Empirical Proton-Neutron Interaction Energy
1991, 15(8): 754-760.
A method for extracting the empirical proton-neutron interaction energy between the last proton and the last neutron,δVpn has been discribed and developed.The results for ground states of all even-even nuclei with N not less than 40 and for high spin states of some nuclei have been discussed.δVpn values at high frequency for given configuration of some odd a nuclei were shown as well.It is found that these empirical δVpn values include all multipole (mostly the monopole and quadrupole) terms of proton-neutron interaction and sensitively depend on nuclear deformation,configuration and rotational frequency.
Effect of Coulumb Screening on Deuterium-Deuterium Fusion Cross-Section
WANG Shun-Jin
1991, 15(8): 761-764.
The popular Gamow formula for the deuterim-deuterium fusion cross-section is generalized to take into account the Coulumb screening effect.The generalized formula has been used to discuss the fusion process occurring in the metal medium.
The q-Deformed KdV Equation
HU Zhan-Ning
1991, 15(8): 765-768.
The q-deformed KdV equation was obtained corresponding to the "quantum"Virasoro algebra,which coincides with the usual one in the limit of q→1.