1991 Vol. 15, No. 10

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Review
The Measurement of the Performance of L3 Hadron Calorimeter With BGO
CHEN Guo-Ming, CHEN He-Sheng, TANG Xiao-Wei, TONG Guo-Liang, WU Yi-Gen, ZHANG Shou-Yu, WANG Yi-Fang
1991, 15(10): 865-874.
Abstract:
The four L3 hadron calorimeter moduies with BGO have been tested with pion beams of energies between 4 and 20GeV.L3 calorimeter,the gas sampling Uranium module and its test with beam are bricfly described.The energy resolution for pions with energies between 4 and 20GeV were measured.The e/pion ratio,angular resolution,dependence of the energy resolution on the direction of incident pions,hadron punch through and track through also were measured and analyzed.
The Radiation Field Measurement in the 200MeV Electron Linac Tunnel
LI Yu-Xiong, LIANG Ren-You, LI Jue-Xin, XU Yun-Hua
1991, 15(10): 875-880.
Abstract:
To measure the radiation level in tunnel during a Linac running period,can provide important data to improve the machine,forcast the lives of electronic devices and other materials,exploit the radiation field as well.This paper introduces the properties of the radiation field around Linac,discusses how to measure the radiation level with alanine dosemeter and ESR method,analyses the result of our measurement.
The Cocycle Condition of Liouville Theory and Its Application to the 2-D Induced Gravity(Ⅱ)
WANG Zhong-Hua, WU Ke, GUO Han-Ying
1991, 15(10): 881-889.
Abstract:
In terms of the cocycle condition of Liouville theory,we have got the composition law in the theory of Beltrami-Liouville gravity as well as its Ward identity and its energy-momentum tensor,i.e. the extended Schwarzian derivative.
Compact Baby Universe Model in ten Dimension and Probability Function of Quantum Gravity
YAN Jun, HU Shi-Ke
1991, 15(10): 890-897.
Abstract:
In this paper,the quantum probability functions are calculated for ten-dimensional compact baby universe model.We find that the probability for the Yang-Mills baby universe to undergo a spontaneous compactification down to a four-dimensional spacetime is greater than that to remain in the original homogeneous multidimensional state.Some questions about large-wormhole catastrophe are also discussed.
Central Extension of the Quantum Deformed Virasoro Algebra
HU Zhan-Ning
1991, 15(10): 898-905.
Abstract:
The quantum deformation of the Jacobi identity was presented and the central extension of the q-deformed Virasoro algebra was found when q is a root of unit.The explicit expressions of the central terms have been obtained with the Beraha q values.
Distribution in Ultrarelativistic Nuclear Collisions
QIAN Lu
1991, 15(10): 906-912.
Abstract:
The distribution of average transverse-momentum of secondary particles produced in the central region of ultrarelativistic nuclear collisions is studied quantatively with the hydrodynamic model and is compared with JACEE data.The energy density function in SU(3) gauge theory given by Monte-Carlo Calculation is employed to describe the state of the hot matter collision.It is found that the abnormal rapid rise of at high initial energy density region is not from the hydrodynamic motion of quark-gluon plasma.The T> distributions with different initial thermal time and initial radius have been discussed in detail,he main character of distribution does not change with the variation of initial parameters.
Three-Body Structure and Interparticle Correlations of the Doubly Λ Hypernucleus ΛΛ6He
DUAN Yi-Wu
1991, 15(10): 913-918.
Abstract:
Based on the ΛΛα three-body model,variational calculations for the doubly Λ hypernucleus ΛΛ6He have been completed with the aid of the harmonic oscillator formlism.Then detailed analysis on the shape-density of the system has been made and the interparticle correlations have been investigated,the mode of internal motion has been found.
The Deuteron Microscopic Optical Potential
LU Cong-Shan, ZHANG Jing-Shang, SHEN Qing-Biao
1991, 15(10): 919-927.
Abstract:
In this paper,the two particle Green's function is introduced.When the direct interaction between two nucleons is neglected,the first and second order mass operators of two particles are the sum of those for each particle.The nucleon microscopic optical potential is calculated by applying nuclear matter approximation and effective Skyrme interaction.Then the deuteron microscopic optical potential (DMOP) is calculated by using fold formula.For improvement of the theory,the two particle polarization diagram contribution to th e imaginary part of the deuteron microscopic optical potential is studied.
Microscopic Analysis of Intruder States and Configuration Mixing in Even-Even Nuclei Near Closed Shells
LI Xian-Yin, ZHAO Xiao-Feng, WANG Yu-Cheng, LIU Yong
1991, 15(10): 928-936.
Abstract:
In this paper,a microscopic theory describing the intruder states in even-even nuclei near closed shells is appiled to calculate the low-lying spectrum and wavefunctions corresponding to 110Cd configurations.The affects of several factors on the formation of intruder states,the mechanism and the strength of configuration mixing are studied systematically.By comparison with phenomenological works,the s-d hamiltonian derived from the microscopic theory is investigated.
Nuclear Shadowing Effect
LI Guang-Lie, YANG Jian-Jun, SHEN Hong-Qing
1991, 15(10): 937-952.
Abstract:
The recent progress in the experiments and theoretical descriptions of the nuclear shadowing effect is presented.
Relativistic Two-body Wave Equation and the Short-range Interaction of Quarkonium
LUO Zhen-Fei, QIU Xi-Jun
1991, 15(10): 953-955.
Abstract:
The Feynman-Hellmann theorem widely used in nonrelativistic quantum mechanics is applied to relativistic two-body wave equations from which we obtain the meson mass formula It is shown that wave equations considered here are unable to describe the short-range interaction of quarkonium reasonably.
Is There a New Parameter in QED
Bruce H, WU Dan-Di
1991, 15(10): 956-960.
Abstract:
The Fermion mass with aparity violating part in quantum electrodynamics (QED) is allowed in principle and hence introduces a new parameter.Explicit parity violating effect,the electric dipole moment is shown.A chiral rotation may turn the mass into real,however,produces a parity violating term in the pure gauge part.The latter is not the total derivative with respect to time and indeed appears in the equations of motion.The second set of Maxweil equation becomes inhamogineous,which violates parity.