1984 Vol. 8, No. 6

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Review
INVESTIGATION OF SOME PROPERTIES OF SQS DRIFT CHAMBER
CHEN Chao-Qing, WANG Yun-Yong, SHI Huan-Zhang, LI Ru-Bai, RONG Gang
1984, 8(6): 657-663.
Abstract:
Some performances of an adjustable field drift chamber operated in the self-quenching streamer mode (SQS) have Been measured. The counting rate plateaus as a function of threshold and gas mixture, the efficiency, the spacil resolution, the relationship between drift distance and drift-time, the pulse heights in different drift distance and the transition characteristics from saturated avalanche to SQS-discharge mode are presented in this paper. The influences of the benzene vapor are also studied.
MEASUREMENT ON CROSS SECTION OF HIGH ENERGY IRON NUCLEUS (E≥4GeV/N)-ALUMINIUM NUCLEUS INTERACTIONS
REN Guo-Xiao, ZHOU Yin-Zao, HUANG Rong-Qing, CHEN Ming-Yuan
1984, 8(6): 664-667.
Abstract:
For the purpose of nucleus-nucleus interaction detection, a detector consisted of CR-39 plastic track detector sheets interlayered with aluminium plates was launched to 37 km height by balloon near Beijing and exposured in the high energy nucleus beam of primary cosmic rays for 10 hours. The obtained Fe-Al interaction cross section (Δz≥1) at energy region higher than 4GeV/N is 1.76±0.18b.
DISCRETE SYMMETRY AND SO(2n) GRAND UNIFIED MODEL
WAN Ling-De, LU Gong-Gu, DU Dong-Sheng
1984, 8(6): 668-676.
Abstract:

A systematic analysis of SO(2n)×S GUT models with discrete symmetry S is presented. It is found that SO(14)×S and SO(16)×S are the satisfactory gauge groups of flavor unification. In addition, SO(14)×S and SO(16)×S models are discussed in detail. Both of them can accommodate four generation light fermions and preserve the asymptotic freedom of SU(3).

STRONG-COUPLING EXPANSION IN σ-MODEL
ZHANG Zhong-Can
1984, 8(6): 677-687.
Abstract:
The general formulation and Feynman rules of strong coupling expansion in σ model are derived. Then the reduction of strong couplig expansion formulation is investigated. Finally, using Pade-type extrapolation technique, a useful research about dealing with divergences is presented.
THE HIGHER ORDER QUANTUM CORRECTIONS IN SPIN-FLIP SYNCHROTRON RADIATION
WU Chang-Qin, Song Hao, NI Guang-Jiong
1984, 8(6): 688-698.
Abstract:
The effect of Synchrotron radiation on the transversal polarization of electrons is investigated. The higher order quantum corrections on spin-flip radiation probability due to the recoil of photon are derived by two approaches. The result reveals a decrease in final polarization and an increase in relaxation time.
THE MICROSCOPIC DESCRIPTION OF 3He(π,n)2H REACTION AT 100—300MeV
XU Xiang-Yuan, CHEN Xue-Jun, LIU Xian-Hui
1984, 8(6): 699-706.
Abstract:
The Isobar model of G.E.Brown et al. for π-nucleus scattering is extended to describe the (π, N) reactions at intermediate energies. The many-body effects are treated by using a phenomenological approximation. The influences of some factors upon the differential reaction cross sections are investigated. These include nonstatic correction, nucleon correlation wavefunction and distorted effect of the outgoing nucleon. The angular distributions of 3He(π,n)2H reaction at 100—300MeV are calculated. The theoretical calculations are essentially consistent with experiments.
INFLUENCE OF NUCLEAR STRUCTURE OF He4 ON He4-NUCLEUS COLLISIONS AT HIGH ENERGIES
KONG Fan-Xin, LIU Ji-Feng, LIU Yuan
1984, 8(6): 707-711.
Abstract:
Adopting rigid projectile approximation, the elastic scattering differential cross section for α+α and α+Ca40 at high energies are calculated on the basis of Glauber's theory. The influence of different single particle density of He4 on elastic scattering is discussed. The calculated results show that the correlation in projectile is of the same importance as that in target.
SPECTROSCOPIC FACTOR OF π NUCLEUS DOUBLE CHARGE EXCHANGE REACTION AND 26Mg(π+, π)26Si REACTION
LI Yang-Guo, LIU Xian-Hui
1984, 8(6): 712-719.
Abstract:
The strength of π-nucleus double charge exchange reaction is related to the spectroscopic factor of two nucleon transfer. In this paper, the relationship between the reaction amplitude and the spectroscopic factors is discussed. As an example, two kinds of nuclear structure are used in discussing the excitation function and the differential cross section of 26Mg(π+, π)26Si. It is shown that the theoretical method can explain the exprimental data.
THE PHYSICAL BASES OF THE THREE PARTICLE SYSTEM
YAO Nai-Guo, YU Zu-Rong
1984, 8(6): 720-731.
Abstract:
In this paper, using the property of the local isomophism between the group SO(6) and SU(4), a set of physical bases of the three particles is derived. The bases are equivalent to the hyperspherical function bases.
DIFFUSION MODEL ANALYSES OF THE EXPERIMENTAL DATA OF 12C+27Al,40Ca DISSIPATIVE COLLISIONS
SHEN Wen-Qing, QIAO Wei-Min, ZHU Yong-Tai, ZHAN Wen-Long
1984, 8(6): 732-739.
Abstract:
Assuming that the intermediate system decayes with a statistical lifetime, the general behaviour of the threefold differential cross section d3σ/dZdEdθ in the dissipative collisions of 68MeV12C+27Al and 68.6MeV12C+40Ca system are analysed in the diffusion model framework. The lifetime of the intermediate system and the separation distance for the completely damped deep inelastic component are obtained. The calculated results and the experimental data of the angular distributions and Wilczynski plots are compared. The probable reasons of the differences between them are briefly disscused.
STATISTICAL CHARACTERISTIC OF THE INITIAL EXCITON NUMBER n0 AND IT'S INFLUENCE ON THE RESULTS IN THE EXCITON MODEL
MIAO Rong-Zhi, WU Guo-Hua, ZHENG Wei-Han, LIU Jian-Ye, YU Chao-Fan, YU Xian
1984, 8(6): 740-747.
Abstract:
It is assumed that the initial exciton number n0 is statistical. The expression of the probability h(n0) for any probable n0 is given. The theoretical calculation results, including the energy spectra and the double differential cross sections, are obtained by weighted summation of the contributions coming from various probable n0. The agreement between experimental data and the theoretical results is quite well.
INVESTIGATION OF DIC FOR REACTION 12C+27Al AT ENERGY 68MeV AND FOR REACTION 12C+natCa AT ENERGY 68.6MeV
XIE Yuan-Xiang, ZHU Young-Tai, FEN En-Pu, YIN Xu, MIAO He-Bing, CAI Jing-Xiang, LI Fa-Wei, SHEN Wen-Qing, SUN Shu-Ming, WEI Jian-Jun, LI Song-Ling, XIAO Qing-Xian, WANG Qi, JIA Sheng-Ming, DUO Han-Hong
1984, 8(6): 748-754.
Abstract:
27Al and natCa target were bombarded by the Carbon beam at incident energy 69.5MeV. The reaction products were identified by ΔE-E telescope and the spectra of Li, Be, N, O elements were obtained.
The values of deformation parameter of emitted fragmente are between 0.28—0.44. Calculated energy of full damped fragments are in agreement with the experimental data. The average life-time of the system is about (4—6)×10-22S.
SOME DISCUSSION ON THE BANDHEAD OF SUPERBAND OF TWO-QUASIPARTICLE EXCITATIONS
GAO Yuan-Yi
1984, 8(6): 755-756.
Abstract:
VMI model is used to analyse the ground band and superband of some nuclei. It is indicated that the angular momentum of the bandhead of superband of two-quasiparticle excitations should be I0≥8+.
A HIGH RESOLUTION SETUP FOR IDENTIFICATION OF HEAVY ION REACTION PRODUCTS
WU Zhong-Li, WANG Qi, ZHU Yong-Tai
1984, 8(6): 757-760.
Abstract:
A heavy ion reaction products identification setup, which consists of a time-offlight measurement system and a ΔE-E telescope, has been constructed. The time resolution of the setup was found to be 250 ps (FWHM) for the elastic scattered particles of (14N+Ni) reaction.
ON THE DETERMINATION OF THE GROUND BAND PROPERTY IN 152Dy
ZHANG Jing-Ye, ZHONG Ji-Quan, LIE Bao-An
1984, 8(6): 761-764.
Abstract:
Using the N~λn and Er(I+2)/Er(I)~I plots, the latest experimental spectrum of the nucleus 15266Dy86 has been further analysed. It is point out that the ground band levels with I=8+ belong to deformed collective band. But values of deformation are less than that of well deformed nuclei. And those levels are more vibrational like than rotational. The hint of pairing disapperance in nuclei 167,169Yband 84Zr is also discussed.
A 8-HIT SAMPLE AND HOLD CIRCUIT
DING Hui-Liang, GUO Ya-Nan, YANG Xi-Rong, YU Zhong-Qiang, GU Song-Hua, SHENG Jun-Peng
1984, 8(6): 765-771.
Abstract:
A sample and hold circuit with 8-hit capacity to be used to drift chamber read out electronics is described. It's integral nonlinearity is better than 0.5% for input pulse with 0—4V amplitude. Sampling error is about 1% with acquisition time of 80 ns. The drop of recorded signal is less than 1% in retention time of 40 ms.
SINGLE LINK PARTITION FUNCTIONS FOR VARIOUS FORMS OF SOURCES AND THEIR APPLICATIONS IN SU(3) LATTICE GAUGE FIELD THEORY
HE Xiang-Hao, LI Tie-Zhong, XIAN Ding-Chang
1984, 8(6): 772-776.
Abstract:
The knowledge of SU(3) single-link partition function is required in many calculations (such as the strong coupling expansion, the mean field and variational approximation, etc.) in lattice gauge field theory. We express the single-link partition functions for various sources in the form of a one-dimensional integral which can esily be carried out on computer. The application of these single-link partition functions in variational computation is discussed.
HOW TO MAKE p→μ+η THE MAIN MODE OF PROTON DECAY
WU Dan-Di, LI Tie-Zhong
1984, 8(6): 777-780.
Abstract:
A model based on Pati-Salam-Sarkar's work is presented in which p→μ+η has a half chance to be the main mode of proton decay.
A COMMENT ON GAUGE SYMMETRY BREAKING OF N=2 SUSY GUTS
DONG Fang-Xiao, DU Dong-Sheng, ZHOU Xian-Jian, XUE Pei-You
1984, 8(6): 781-784.
Abstract:
The possibility of constructing at a realistic SUSY GUT model by use of N=2 finite supersymmetric theory is discussed. We find that the spontaneous breaking of gauge symmetry and supersymmetry can be realized, but it is difficult to make the quarks and leptons to acquire small masses.