1998 Vol. 22, No. 4

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Self-affine Fractality of Multiparticle Productionin pp Collisions at 400 GeV/c
Wang Shaoshun, Wang Zhaomin, Wu Chong
1998, 22(4): 289-292.
A Self-affine fractality analysis was performed by using the experimental data of multiparticle production in pp collisions at 400GeV/c. Compared with the results obtained from the selfsimilar analysis, the self-affine fractality analysis shows a better scaling behavior within the limits of the experimenal resolution.
Comments on the Ratio of Hadronic Decay Rates of ψ(2S)to J/ψ
Li Xinhua, Gu Yifan
1998, 22(4): 293-298.
The perturbative QCD prediction of “15% rule” for the ratio of ψ(2S) to J/ψ hadronic decay rates suffers seveal apparent approximations. Calculations using existing experimental data are made in this paper; further corrections to this radio for a number of exclusive decay channels are also discussed.
Lifetime Measurements of the States Around the Backbend in 126Ba
Li Guangsheng, Dai Zhengyu, Liu Xiang'an, Zhang Lankuan, Wen Shuxian, Yuan Guajun, Wu Xiaoguang, Weng Peikun, Li Shenggang, Yang Chunxiang
1998, 22(4): 299-301.
The high spin states in 126Ba were populated by means of the reaction 116Sn (16O,2p4n)126Ba at the beam energy of 73MeV. Lifetimes of the states around the backbend in the yeast band were measured by using the Doppler shift attenuation method. The corresponding normalized B(E2) values are pronouncedly reduced for the 10+ and 12+ states. The experimental results are compared with the theoretical predictions of the particle-rotor model.
Neutron Yields and Neutron Emission Rate in the ForwardDirection for 50 MeV/u 18O-ion on Thick Be,Cu,Au Targets
Li Guisheng, Zhang Tianmei, Li Zongwei, Su Youwu, Zhang Shumin
1998, 22(4): 302-306.
The neutron yields and the neutron emission rates in the forward direction for 50MeV/u 18O-ion induced reactions on thick Be, Cu, Au targets have been measured using the threshold detector activation method. The measured results indicate that the neutron yield and the neutron emission rate depend on the atomic number of target nuclei; neutron yield for the lighter target is greater than that for the heavier one. The neutron yield for 50MeV/u 18O-ion on Cu is about four times as large as that for 50MeV/u 12C-ion on Cu when incident energies per nucleon are identical.
Color Rearrangement in e+e→W+W→h's Process
Si Zongguo, Xie Qubing, Wang Qun
1998, 22(4): 307-314.
The probability of Color Rearrangement at partonic level in e+e→W+W→h,s process is studied using the Color Effective Hamiltonian. The comparison between our results and those of Gutafson and Sjostrand et al. is also given. It is found that this probability cannot be neglected, and it is pointed out that to investigate the Color Rearrangements, the hadronization models should be developped and improved.
Analytical Study of Lattice U(1) Gauge-Higgs ModelsWith Fixed Modulus
Ren Xuezao, Chen Ying, Zhu Yunlun
1998, 22(4): 315-321.
Using variational cumnulant expansion we study the lattice U(1) gauge-Higgs models with fixed modulus To determine the variational parameters, we combine main-value method and accumulated point method. The phase diagrams obtained are consistent with Monte Carlo results. We also calculate Polyakov line 〈L〉 with Nτ=1 in finite temperature.
Fifth Order Approximate Analytic Calculation of (2+1)-D SU(2) Vacuum Wavefunction
Hui Ping
1998, 22(4): 322-325.
In this paper, the unimodular condotion is used to choose the graphicses reasonaly, fifth order graphicses are deduced from the first, second, third and fourth order graphicses. The fifth order results obtained are satisfactory.
Three Body Amplitude Analysis of the Process a2(1320)→π+π+π
Zhu Jiejie, Ruan Tunan
1998, 22(4): 326-332.
We analyze the decay amplitudes of the process a2(1320)→π+π+π using the tensor analysis method and show how to obtain three body amplitudes.
Self-Similar Strcture Shell Model
Wang Zhengda, Zhang Xiaodong, Wang Xiaochun, Wang Xiaobin
1998, 22(4): 333-340.
In Order to extend the conventional shell model(SM) calculation with harmonic oscillator bases to halo nuclei, a self-similar, structure shell model(SSM) is proposed. The SSM is achieved by a rescaling of both the Kinetic and potential energy term of the harmonic oscillator and a mean field imitation, so that the single particle orbit in SSM has state (orbit) -dependent frequency. The large r. m. s. radius and the thick neutron skin for halo nuclei as well as the bound state properties of Borromean nuclei such as 6He, 11Li and 14Be can be reproduced.
Nuclear Gluon Distribution Due to Parton Evolution and Recombination in Nuclear Environment
Zhu Yabo, Yang Jianjun
1998, 22(4): 341-345.
In this paper, in consideration of the recombination among sea quarks and gluons leaking out of the bound nucleon, and the evolution of partons confined in the nucleon due to the change of confinement size, we give a general description of nuclear gluon distribution and calculate the gluon radio of nuclei Sn to C, which is in agreement with NMC experimental data.
String Tension and Production of Strange Particles
Tai An, Sa Benhao
1998, 22(4): 346-350.
The increase of effective string tension as a result of the hard gluon kinks on a string is investigated using a parametrization form. In this form the effective string tension increasing with energies in hadron-hadron collisions is due to the mini-jet (gluon) production in the collisions. The data for the energy dependence of the strange quark suppression factor in hadron-hadron collisions are very well reproduced with this mechanism. Meanwhile, the experimental phenomena of approximate energy independence of the strange quark suppression factor in e+e -annihilations are discussed.
Energy Staggering in the High K Rotational Band
Liao Jizhi
1998, 22(4): 351-358.
Introducing the staggering index S(I) to describe the energy spectra of the λrigid and λ-soft nuclei, it becomes very clear that there are two kinds of energy staggering for which the S(I) -I plots have opposite zigzag behavior. They can be described using the axially asymmebtric rotor model with vibration-rotation coupling and the interaction boson model O(6) limit with three-body potential or the angular momentum projection deformed Hartree-Fock method (PDHF ), respectively. The theoretical predictions for the characteristics of the staggering in high K rotational band are given. Analyzing the experimental data of high K band spectra of the nuclei in the mass range. 160, it is demoastrated that the energy staggering does exist in the high K band. At the same time, some evidences for the shape transition indicated by zigzag phase change of S(I)-I plots are undoubtedly found.
Inclusion of g Boson in the Microscopic sdgIBM andthe g Boson Effect
Han Guangze
1998, 22(4): 359-367.
The inclusion of g boson in the microscopic sdglBM is preseated. The collectivity of g boson, the relationship between g boson propernties and the strengths of the effective nucleon-nucleon interaction, and the influence of g boson on the sdlBM are discussed in detail.
HFSS Design of KEKB Longitudinal Feedback Kicker
Pei Guoxi
1998, 22(4): 368-372.
The longitudinal feedback kicker used to overcome bunch-bunch coupled instabilities of high luminosity accelerators is introduced. HFSS simulating of lambe-rtson Kicker has been given, and the results are in good agreement with experiments.
Enhanced-hydrogenation of Bombarded Surface of Mg-Ni Eutectic Alloy
Wang Zhenxia, Pan Jisheng, Zhang Jiping, Xu Xunjiang, Zhu Jingping, Zhang Huiming
1998, 22(4): 373-377.
Hydrogenated effect of the Mg-Ni alloy surface caused by 27keV Ar+ ions bombardment has been studied. The enhancement of hydrogenated effect depends on fluence, A model of change-surface of catalyzed-phase due to ion bombardment is proposed to describe this phenomenon of hydrogenated enhancement in the present Work.
X-Ray Analysis of Light Elements by Monochromatic Light
Liu Shijie, Hu Zhaohui, Yao Ying, Wang Dewu
1998, 22(4): 378-382.
As variable energy monochromatic sources both synchrotron radiation monochromatic light and proton induced X-ray emission were used to study X-ray florecence of K、Ca、Ti light elements. The results indicate that this method not only reduces the bremsstrahlung background but also eliminates the interference with some other elements by selecting appropriate exciting energy. Thus the analytic sensitivity of K、Ca、Ti elements are considerably improved.