1998 Vol. 22, No. 03

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Review
Anomalies of Neutron and γ-Ray Emission in Ternary Fission of 252Cf
Han Hongyin, Huang Shengnian, Shen Guanren, Qiao Ying, Sun Gang
1998, 22(03): 193-199.
Abstract:
In a four-parameter experiment the correlation between the neutron and γ-ray emission and the kinetic energy of the light-charged-particles (LCPs), such as alphas, tritons, deuterons and protons, was measured. The results show that the positive correlation called anomalies of the neutron and γ-ray emission in this paper, was observed for fission accompanied by low energy LCPs. In the case of high energy LCP emission, however, negative correlation was obtained. On the basis of the model calculation, the positive correlation is discussed tentatively.
Performance Estimation of a High Precision Central Drift Chamber Used to Detect Low Momentum Particles
Tong Guoliang, Huang Xiuping, Ma Jimao, Chen Chang, Zhang Qinjian, Wu Yigen, Yi Kai
1998, 22(03): 200-208.
Abstract:
The momentum resolution and ionization energy loss in a high precision central drift chamber used to detect the low momentum charged particles are estimated. The measurement of the low momentum charged particles and the particle identification by the dE/dx method with the chamber are discussed. The detection of two typical physics processes is investigated.
Band Crossings and Shape Changes in the Kπ=5-/2 Band in 79Kr
Pan Qiangyan, Luo Yixiao, De Poli, de Angelis
1998, 22(03): 209-216.
Abstract:
High-spin states in 79Kr were studied via the fusion evaporation reaction 55Mn(30Si, apn) at 130MeV. Prompt γγγ-charged particle coincidences were made using the GASP array in conjunction with the ΔE-E Si(Au) charged particle ball. Nine new states were found, along with 10 new transitions in the K=5-/2 band. The favored (a=+1/2) and unfavored (a=-1/2) signature sequences were extended up to states of (37-/2)8992 keV and (59-/2)20132 keV, respectively. A cranked shell-model analysis has been made to discuss the experimental results.
Calculation of Wilson Loop Functionals for Classical and Quantum Gravities
Chen Zhongqiu, Shao Changgui, Ma Weichuan
1998, 22(03): 217-224.
Abstract:
Using perturbative method we calculate Wilson loop functionals (WLFs) for Kerr gravitational field and for R+ R2+R..R.. + R....R.... quantum gravity. The results show that localized curvature excitations of order hκ2 exist in this type of higherderivative quantum gravity
Algebraic Structure of Two-Parameter Deformed Multi-mode Bose Operators and Their Applications (Ⅲ)
Yu Zhaoxian, Zhang Dexing, Liu Yehou
1998, 22(03): 225-233.
Abstract:
The eigenstates of the higher power of the two-paranneter deformed multi-mode bose opcmtors are constructed. It is found that they form a complete Hilbert space Further more, the mathematical structure and the corresponding boson realization of the two-parameterr deformed quantum algebra SLq,s(3) are given, and the 1/2 ratk tensor-like operators of SLq,s(2) are also presented. It is pointed out that the results of SLq,s(3) is easily generalized to a multi-mode case.
Multiplicity of D in e+e Annihilation at s=29─35Gev
Chen Esheng, Wang Qun, Xie Qubing, Chen Yan
1998, 22(03): 234-240.
Abstract:
We question the validity of the multiplicity data 〈D*++D*-〉=0.43±0.07 in e+e annihilation at s= 29-35 GeV which is listed in Review of Particle Physics. After annalyzing five sets of data provided by five different collaborations, we derive the world average value: 〈D*++D*-〉=0.24±0.02 This result is in contradiction with that listed in Review of Particle Physics.
Classical Transport Equation of Quarks Consistent With Quantum Transport Equation
Chen Xiandjun, Zhang Weining, Huo Lei, Liu Yiming
1998, 22(03): 241-246.
Abstract:
In this paper, a dynamic variable S is used to describe quark spin and the classical transport equation of quarks is set up. The onsistency of the classical transport equation with quantum ransport equation is discussed. Some properties of classical distribution function in color and spin spaces are explored through comparing the consistency.
Contribution of Negative Energy Sea in the σ-ω Model
Yao Yujie, Chen Xiaodong, Wu Shishu
1998, 22(03): 247-254.
Abstract:
It is shown that if the contribution of the negative energy sea is taken into account a good saturation curve and a good result of in compressibility K—1v, can be obtained in the relativistic σ-ω Model. The divergent integrals are dealt with by the form factor regularization scheme. The effect of the contact interaction caused by the ω-meson is investigated in some detail. The average residual number of mesons per nucleon in the nuclear ground state is also calculated.
Study of K-meson Photoproduction and Associated Radiative Capture Process
Lu Minghui, Ma Weixing, Bijan Saghai, Li Zhenping
1998, 22(03): 255-259.
Abstract:
We analyse K-meson photoproduction off proton and its associated radiative capture process in Low Energy QCD Lagrangian. The two processes.are related to each other by the Crossing Symmetry. In the framework of chiral quark model, we give a unified description of the two processes. Our theoretical prediction for branching ratio in radiative capture process is in good agreement with the experimental data.
Study of Spectra with Boson ConfigurationMixing and Surface Delta Interaction
Zhang Qingying, Fu Liping
1998, 22(03): 260-264.
Abstract:
The energy spectra and E2 transition probabilities of three-boson nuclei 46Ti and Cr are studied by using the configuration mixing wave function in sdgIBM1 and the boson surface delta interaction. The theoretical result in sdgIBM1 is satisfactory,it can fit much more levels and E2 transition probabilities, and their deviations are even smaller than those is sdIBM1. It is shown that the g boson also plays important role in the vibration region.
Effect of Angular Momentum on Prescission Particle Multiplicity for the Reaction of 10.6MeV/u 84Kr on 27Al
Ye Wei, Shen Wenqing, Lu Zhongdao, Feng Jun, Ma Yugang, Wang Jiansong
1998, 22(03): 265-270.
Abstract:
The effect of angular momentum on the prescission particle multilplicity in the reaction of 10.6MeV/u 84Kr(27Al,binary fission) is studied using generalized fission diffused model.The prescission particle multilplicity and the scission time are found to increase with decreasing angular momentum. Most of the prescission particle is emitted before saddle. The consistency with the experimental particle multiplicity is obtained when we average with weight over angular momentum contribution to binary fission reaction. At the same time other factors which influence the prescission multiplicity and scission time are also discussed.
Systematics Research on (p, n) and (p,2n) Reaction Excitation Functions
Ma Yinqun, Zhuang Youxiang, Zhang Zhengjun
1998, 22(03): 271-276.
Abstract:
On the basis of Planck formula of black body radiation and experimental data, an empirical systematic formula with two djustable parameters is presented. For incident proton energies from threshold to 1 50MeV and target masses in 44<A<239 and 44<A<242 region, this formula can describe (p, n) and (p, 2n) reaction cross sections nicely.
Calculation for the Longitudinal Transition Amplitudes of Baryon Resonances
Dong Yubing
1998, 22(03): 277-282.
Abstract:
The relativistic configuration mixing effect on the longitudinal transition amplitudes S1/2(Q2) is investigated. The study shows that the effect plays an important role in understanding of the longitudinal transitions of baryons.
Rem-Meter Correction Factor for Measuring High Energy Neutrons Inside Shielding
Li Guisheng
1998, 22(03): 283-287.
Abstract:
The dose equivalent of neutrons from intermediate energy heavy ion reactions measured with a rem-meter would be underestimated because of the energy response of the instrument. Therefore the readings of rem-meter must be corrected in order to obtain the real dose equivalent The correction factors for dose equivalent ofneutrons from the reactions of 41.7MeV/u 12C+Fe and 100MeV/u 12C+C measured inside . shielding with both rem-meters the 10 in. diameter single-sphere rem-meter and the standard A-B rem-meter have been calculated. They could be applied in dose equivalent measurement for intermediate energy heavy ion reactions.