1997 Vol. 21, No. S4

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Factorial Moments of Continuous Order and Multifractal Analysis in 400 GeV/c pp Collisions
Wang Shaoshun, Zhang Jie, Ye Yunxiu, Xiao Chenguo
1997, 21(S4): 1-10.
The method of factorial moments Fq of continuous order suggested by Hwa has been tested. It was found that using this method to analyze the experimental data will not produce satisfactory results. Some improvements were made for Hwa,s method,making it suitable for multifractal analysis of experimental data. The analytic results for the experimental pseudorapidity distributions of charged particles produced in 400 GeV/c pp collisions indicated that the method of the factorial moments of continuous order is feasible. There is possibly multifractal behavior in the process of multiplicity production in pp collisions at 400 GeV/c.
Correlation Between Sun Shadows of 10 TeV Cosmic Ray and the Solar Activity
Liu Shaomin, Ding Linkai, Shi Ce, Zhaxiciren, Zhaxisanzhu, Mu Jun, Wnag Hui, Lu Hong, Feng Zhenyong, Ren Jingru, Yu Guangce, Zhou Wende, Labaciren, Meng Xianru, Meng Lie, Zhang Jilong, Zhang Chunsheng, Zhang Huimin, Shi Zhizheng, Jia Huanyiu, Mei Dongming, Huang Qing, Tan Youheng, Huo Anxiang, Dai Benzhong
1997, 21(S4): 11-18.
Using data obtained in the period of June 1990-October 1993, the shadows of the Sun and the Moon have been detected at 5.7σ and 7.1σ levels, respectively, in the lOTeY cosmic ray flux by the Tibet air shower array at an altitude of 4300 m above sea 夏evel. The shadow of the Sun is found to be deflected away from the Sun by 0.62° to the west and 0.22° to the south by the interplanetary magnetic field. The correlation between the shadow of the Sun and the solar activity and its asymmetry are studied in detail. A new qualitative explanation to the shift and yearly variation of the Sun,s shadow is presented.
Experimental Study of Hadron Inclusive Production in J/ψ Energy Region
Bai Jingzhi, Bian Jianguo, Chai Zhengwei, Chen Guangpei, Chen Hongfang, Chen Jiangchuan, Chen Shaomin, Chen Yaqing, Chen Yu, Chen Yuanbo, Cheng Baosen, Cui Xiangzong, Ding Huiliang, Du Zhizhen, Fan Xiaoling, Fang Jian, Gao Cuishan, Gao Meili, Gao Shuqi, Gu Jianhui, Gu Shudi, Gu Weixin, Gu Yifan, Guo Yanan, Han Shiwen, Han Ying, He Jingtang, He Ju, He Mao, Hu Guiyun, Hu Jingliang, Hu Qionghui, Hu Tao, Hu Xiaoqing, Huang Xiuping, Huang Yinzhi, Jiang Chunhua, Jin Shan, Jin Yan, Kang Shuhui, Ke Zunjian, Lai Yuanfen, Lan Huibin, Lang Pengfei, Li Jin, Li Peiqin, Li Qun, Li Rubai, Li Wei, Li Weidong, Li Weiguo, Li Xinhua, Li Xiaonan, Lin Shuzi, Liu Huaimin, Liu Jing, Liu Jinghua, Liu Qi, Liu Rongguang, Liu Yan, Liu Zhenan, Lu Feng, Lu Junguang, Lu Jianye, Luo Shuanqun, Luo Yong, Ma Aimin, Ma Encheng, Ma Jimao, Mao Huishun, Mao Zepu, Meng Xiangcheng, Ni Huiling, Nie Jing, Qi Nading, Qiu Jinfa, Qu Yunhe, Que Youkun, Rong Gang, Shao Yuying,
1997, 21(S4): 19-26.
The mean multiplicities of mesons π±, π0, K±, Ks0, K*0, K, and φ and baryons p, Ξ±, and ∑± (1385) are measured for the first time at J/ψ region with 200,000 events collected at the BEPC with the BES detector. The results are compatible with LUND and Shandong phenomenological models. Based on the experimental results, the strangeness suppression factor s/u and spin suppression factor V(V+P) can be calculated to be ~0.3 and ~0.3-0.5, respectively, which are in good agreement with those given by the ARGUS Collaboration in the Υ region. This indicates that the SU(6) breaking is consistent in the energy region from J/ψ to Υ.
Nuclear Structure of Nuclei in Lead Region (II) Non-Unique First-Forbidden β Decays of Nuclei 208Tl,208Pb,and 206-208Hg
Zhang Changhua, Gu Jinnan
1997, 21(S4): 27-32.
The non-unique first-forbidden β decays of 208Tl, 208Pb, and 206-208Hg are calculated in terms of the shell model with different interactions and model space. The calculated log f0t value very sensitively depends on the effective interactions used in diagonalizing the energy matrix. The β decay modes for 206Hg and 208Hg are also compared.
Chaotic Motion of Classical Particles in Axially Symmetric Potentials with Octupole Deformation
Li Junqing
1997, 21(S4): 33-40.
The fact that there are more prolate-deformed nuclei than oblate-ones in nature is found to be related to the chaotic motion of nucleons. The primary investigation with classical theory showed that the particle motion in the potential with oblate-plus-octupole deformation could become chaotic at a smaller deformation strength as compared with the case of prolate-plus-octupole deformation. The reason is that the negative curvature in the potential surface could appear at a smaller deformation strength for the former one.
Energy Coherence and Charge Diffusion in Dissipative Reaction
Lu Jun, Wang Qi, Zhu Yongtai, Xu Hushan, Li Songlin, Zhang Yuhu
1997, 21(S4): 41-46.
In the framework of the transport theory,the distribution of coherent energy width versus N/Z in the 19F+51Y dissipative reaction is extensively discussed. It can be concluded that the charge equilibrium is reached in the present colliding system. The charge diffusion coefficient is extracted from the theoretical analysis. The linear relation between the distribution width and the average interaction time is ascribed to the charge diffusion process. The effects of the cross correlation between different isotopes on the fluctuation amplitude is also discussed in the paper.
Relativistic Mean-field Calculation on Λ Hypernuclei
Shen Yaosong, Ren Zhongzhou
1997, 21(S4): 47-54.
The ground-state properties of Λ hypernuclei are studied theoretically using the relativistic mean-field theory with TM1 and NL-SH force parameters. It is found that these new parameters can very satisfactorily reproduce the ground-state properties of A hypernuclei. The parameter sets TM1 and NL-SH give very similar descriptions on hypernuclei. The properties of hypernuclei in baryon-hyperon systems are insensitive to the force parameters of effective nucleon-nucleon interactions. The influence of the pairing forces is also taken into account in the study of the Λ hyperon and it is found that it leads to an even-odd effect.
Dynamics of Phase Transition Including Quark-Fragment Effects for an Expansion Quark-Gluon Plasma
Li Panlin, Wu Hua, Xu Mengjie
1997, 21(S4): 55-64.
The (1+1) dimensional relativistic hydrodynamics equation with a source term including quark-fragment effects is numerically solved and the evolution of energy density, flow rapidity, and baryon number density as the characteristic values of the phase transition possibly produced in nuclear collisions at extreme high energy are also analyzed. The quark-fragment effects in the source term are described by using the phenomenological SU/(3) string model with a flavor dynamics.
The numerical results are compared with Kajantie's data. It illustrates indirectly that the results are consistent with the experimental data. The physics picture of our model presented in this paper shows that the phenomenological self-consistent model is reasonable.
Particle-group Correlations and Collectivity for 2.1A GeV Ne+NaF Collision
Zhang Weigang
1997, 21(S4): 65-72.
A concept of particle-group correlations is proposed in this paper. In accordance with the new concept, a new method of collective flow measurement is constructed. Using the new method, the particle-group correlations arising from collective flow are studied with 4π data for 2.1A GeV Ne+NaF collisions at the Bevalac streamer chamber. Through comparison with the Monte Carlo results, the collectivity of the particles in the final state of this collision is inferred in the range of 75 to 95%.
“Neck” Formation and Fragmentation in Intermediate Energy Heavy-ion Collisions
Chen Liewen, Ge Lingxiao, Zhang Fengshou
1997, 21(S4): 73-78.
Under different impact parameters, the collision system of 30 MeV/u 40Ca+40Ca is investigated in terms of the QMD model. It is shown that the number of EMFs is largest at impact parameter b=6 fm, which is due to the formation of "neck" in the collision process. It is also found that, in the process of the formation of "neck," the growth of the relative density fluctuation of the reaction system is very slow and the saturation value is small, which imply the character of the shape instability.
On Ground-State Correlation in Nuclear Many-Body Systems
Xing Yongzhong, Xu Gongou
1997, 21(S4): 79-86.
The ground-state correlation in model systems with different interaction strengths and particle numbers has been studied. Numerical results tell us that if the ground-state shape is quite stable, the ground-state correlation can be approximately explained by the zero-point vibration based on the static self-consistent field calculation. However, around the critical point where the monopole deformation begins to occur, behaviors of the ground-state correlation become very complicated and sensitive to the variation of controlling parameters. It seems to indicate that particular attention should be paid to ground-state correlations in further studies of light nuclei near the drip line.
I=2 Energy Staggering in Superdeformed Bands in 149Gd(b1) and 153Dy(b1)
Xing Zheng, Chen Xingqu, Wang Xiaochun
1997, 21(S4): 87-92.
The particle-rotor model is extended to describe the odd A superdeformed nuclear states in the A~150 mass region. The calculated △I=2 staggering in superdeformed bands in 149Gd(b1) and 153Dy(b1) is compared with the observed data for the first time.
Dimensional Changes of Amorphous Alloys Under Swift Ar Ion Irradiation
Liu Changlong, Hou Mingdong, Wang Zhiguang, Cheng Song, Sun Youmei, Zhu Zhiyong, Jin Yunfan, Li Changlin, Wang Yinshu, Meng Qinghua
1997, 21(S4): 93-98.
Small strips of amorphous alloys Fe77.2Mn0.8Si9B13, Fe39Ni39V2Si12B8, Fe47Ni29V2Si6B16, and Fe40Ni40Si12B8 were irradiated below 50°K with 2.79 MeV/u Ar ions delivered from Heavy Ion Research Facility in Lanzhou (BDDRFL). The macroscopic dimensions of the samples were measured at room temperature before and after irradiation by means of optical microscopy. The observed dimensional changes of all the samples are very small for the low fluency of 1.5×1014Ar/cm2. Upon the increase of ion fluency to 1.6×1015Ar/cm2, dramatic and irreversible dimensional changes are observed and the measured relative changes in width, △b/b0, are in the range of 4.3-12.0%. The results are qualitatively discussed.
q-Analog Boson Inverse Operators and Their Application
Wei Lianfu, Wang Shunjin, Jie Quanlin
1997, 21(S4): 99-103.
The inverse of the q-analog boson creation and annihilation operators is introduced. By virtue of the properties of aq-1 and aq+-1 the q-analog deformation form of the photon-added coherent states is constructed and its completeness relation is discussed.