1997年, 第28卷, 第3期　
刊出日期：1997-10-30

  

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  Nonrelativistic Shifted-1 Expansion Technique for Three- and Two-Dimensional Schrodinger Equation

  Omar Mustafa, Thabit Barakat

  理论物理通讯. 1997, 28(3): 257-264.

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  The shifted-1 expansion techniques (SLET) has been developed to get eigenvalues of Schrödinger equation in three (30) and two dimensions (2D). SLET simply consists of 1/l as a perturbation parameter, where l= 1 -β.β is a suitable shift, l is the angular-momentum quantum number for the 3D-case, l = |m| for the 2D-case, and m is the magnetic quantum number. Unlike the shifted large-N expansion theory (SLNT), SLET seems to be applicable to a wider number of problems of significant interest in physics.
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  The DV-X_α Calculations of Optical Spectra and Their Pressure-Induced Shifts for Ruby

  MA Dongping, D. E. Ellis, LIU Yanyun, CHEN Jurong

  理论物理通讯. 1997, 28(3): 265-270.

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  The R line and U band at normal pressure and their pressure-induced shifts of ruby have been calculated by making use of the SCF embedded-cluster discrete variational (DV-X_α) method. The calculated results of the spectral pressure-induced shifts of ruby by making use of the crystal-field theory have also been given. The results of the first-principle calculations are in very good agreement with the experimental data and the calculated results by using crystal-field theory. The results of local lattice relaxations around the Cr³⁺ ion are obtained by the DV-X_α calculations.
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  Quantum Nondemolition Measurement in Two-Photon Optical Bistability

  YANG Guojian, WANG Kaige

  理论物理通讯. 1997, 28(3): 271-276.

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  We evaluate the effectiveness of the quantum nondemolition (QND) measurement scheme in an effective two-level atomic configuration by using the input-output formalism and the quantum regression theorem. The QND capability can be promoted greatly as the cavity detuning is swept towards the bistability threshold.
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  Quantum Inverse Scattering Method for an Integrable Model

  ZHAO Hongwei, LIU Wuming, PU Fucho

  理论物理通讯. 1997, 28(3): 277-282.

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  The exact eigenstates of the Hamiltonian for a quant um three-wave interaction system with boson-fermion operators are constructed by the quantum inverse scattering method. The Bethe-ansatz equations are obtained from the periodic boundary conditions.
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  Dynamics and Thermodynamics of Layered Neural Network

  JI Daoyun, HU Beilai, CHEN Tianlun

  理论物理通讯. 1997, 28(3): 283-288.

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  We consider the dynamics of overlaps in a layered network with tanhβ(χ) as its threshold transfer function. The analysis of dynamical stability shows that when the external stimulus is close enough to one of the stored patterns the retrieval state becomes globally stable. The statistical mechanics of the same model, in which the parameter β is introduced as thermal noise, is also studied. We find that the thermodynamical stability is equivalent to the dynamical stability.
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  Geometric Constructions of Toda and Periodic Toda Chains

  GUO Maozheng, LIU Xufeng, QIAN Min, WAN Bailing

  理论物理通讯. 1997, 28(3): 289-294.

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  A geometrical and neat framework is established to derive both Toda and periodic Toda systems from the geodesics of symmetric spaces. The counterpart of the Iwasawa decomposition of a semisimple Cie group in the case of a loop group is also derived. By these, we get a Lie su balgebra with Lie bracket [,]R, and the corresponding Poisson bracket {,}R gives the Hamiltonian form of the periodic Toda chains.
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  A New Recursion Relation of Fractional Parent age Coefficients in L-S Coupling Case

  SUN Hongzhou, HAN Qizhi

  理论物理通讯. 1997, 28(3): 295-300.

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  A system of identical fermions with single orbital angular momentum l and spin 1/2 is under consideration. A new recursion relation with explicit seniority of fractional parentage coefficients in L-S coupling case is derived by using the generalized Wigner-EcJcart theorem of semisimple compact Lie groups.
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  Extended PCAC Relation and Nucleon Structure

  S. YING

  理论物理通讯. 1997, 28(3): 301-312.

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  We explore a consistent way to extend the old partially conserved axial vector current (PCAC) relation for a nucleon to a finite q² region. The paper includes an investigation of a chiral Ward-Takahashi identity, the explicit chiral symmetry breaking by a finite current quark mass, the extension of the PCAC relation and the physical consequences. Two explicit relationsbetween the nucleon axial vector form factor g_A(q²), pseudo-scalar form factor g_p(q²) and the pion-nucleon coupling constant g_πNN(q²) are obtained. One of the relations is confirmed, within the experimental error, by observations in the 0 < -q² < 0.2 GeV² region. The other one which. relates g_A(q²) and f_π(q²)g_πNN(q²) is studied by using known empirical facts and dispersion relation. Certain inconsistency, which is in favor of the introduction of a diquark condensation inside a nucleon, is revealed.
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  Study on the Strong-Coupling Scheme to Conserve the Symmetry SU(3) of the Fermion Dynamical Symmetry Model

  WU Lian'ao

  理论物理通讯. 1997, 28(3): 313-326.

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  The strong-coupling wavefunction to conserve the symmetry SU(3) is discussed in detail. In this scheme, a Hamiltonian to conserve the symmetry SU(3) can be approximately rewritten as new forms in the intrinsic frame. It turns out that the particle-rotor model, the odd-odd nuclear spectra, the negative parity bands and the famous Cranking model etc. can be given microscopically under a certain limits. The scheme also provides an approach to considering any-order finite particle effect and mixture of various representations of SU(3).
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  Glueball Masses from Hamiltonian Lattice QCD

  HU Lian, LUO Xiangqian, CHEN Qizhou, FANG Xiyan, GUO Shuohong

  理论物理通讯. 1997, 28(3): 327-332.

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  We calculate the masses of the 0⁺⁺, 0^-- and l^+- glueballs from QCD in 3+1 dimensions using an eigenvalue equation method for Hamiltonian lattice QCD developed and described by S.H. GUO et al. The mass ratios become approximately constants in the coupling region 6/g²∈[6.0,6.4], from which we estimate M(0^--)/M(0⁺⁺) = 2.44 ± 0.05 ± 0.20 and M(l^+-)/M(0⁺⁺) = 1.91 ± 0.05 ± 0.12.
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  Charged Solitons and Their Exotic Angular Momentum

  MA Zhongshui, YE Hua, WU Shenshang

  理论物理通讯. 1997, 28(3): 333-338.

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  We study the model of an Abelian vector field with Chern-Simons terms coupled to fermions in (2+1) dimensions and quantize it canonically using the Dirac-Bergmann algorithm. An equivalent theory of constructed vortex field is established in the Hamil tonian formalism in which the long-range interaction has been removed and short-range interaction is taken up the former position. These vortex fields obey the fractional statistics in general, make the long-range effect in its structure, and satisfy a set of Bogomol'nyi-type equations. We further show the exotic statistics for these configurations and establish an angular-momentum-anomaly connection.
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  What About the Contribution from Reggeons in Hard Process of Strong Interactions?

  PENG Hong'an, ZHAO Shihua, QIAO Congfeng

  理论物理通讯. 1997, 28(3): 339-346.

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  We discuss in this paper the possible contributions from IR_ρ (ρ-reggeon associated with ρ meson) in DIS process on protons. Using results from phenomenological analysis of high energy π-N charge-exchange scattering process, we get the expression of effective propagator of IR_ρ and the coupling constant β_ρ between IR_ρ and light quarks. As a simple and concrete example, we use them to evaluate the contributions of ρ to F₂(χ, Q²) from charge-exchange photoproduction quark-pair process, γ^* + p → n + q_u + q_d(→ n + X), in HERA kinematical regions. For comparison, we also evaluate contributions both from pomeron and partons in the same process. The ratio of contributions in F₂(χ, Q²) from IR_ρ versus IP is larger than 1%, therefore, the former may be tested experimentaly.
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  Detection of Supersymmetric Dark Matter

  HOU Xinrui, LI Xueqian, MENG Xinhe, TAO Zhijian

  理论物理通讯. 1997, 28(3): 347-354.

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  A re-analysis of a heavy charged particle production event observed at the cloudy chamber of the Yunnan Cosmic Ray Station (YCRS) in 1972 indicates that the mysterious heavy particle may be identified as a supersymmetric (SUSY) particle produced by a bombard of a neutral SUSY cosmic ray particle on proton. Based on the assumption, following the literatures that the neutral SUSYparticle which constitutes the main fiaction of the cold dark matter is scalar neutrino (sneutrino) or neutralino (photino), we evaluate the flux of such SUSY particles which gain sufficient energies via elastic scattering with charged cosmic particles on the way to an Earth detector and the capture rates in both the sneutrino and photino cases respectively. The errors appearing in the study are briefly discussed and this work may provide a basis of designing cosmic ray detectors to search for SUSY particles from the heaven.
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  Intensity Dependence of the Photoelectric Effect Induced by a Circularly Polarized Laser Beam

  ZHANG Qiren

  理论物理通讯. 1997, 28(3): 355-358.

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  The intensity dependence of the energy and the angular distribution for photoelectrons ejected by a circularly polarized laser beam is derived. The energy shift is similar to that of a combined Zeeman-Stark effect in magnetic and electric fields perpendicular to each other.
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  Dynamics of Bose-Einstein Condensed and Excited Atoms in a Quantized Cavity

  YI Xuexi, SUN Changpu

  理论物理通讯. 1997, 28(3): 359-362.

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  The dynamics of the Bose-Einstein condensed and excited atoms in a cavity interacting with quantized electromagnetic field of single mode is studied for both the cases with and without dissipation. It is shown that the frequencies of oscillation between the condensed atomic state and an excited state are related to the number of Bose-Einstein condensed atom in a certain form. This relation may be used for the reliable detection of the appearance of the Bose-Einstein condensate.
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  The Structures of Triply Excited Intrashell F and G States

  BAO Chengguang

  理论物理通讯. 1997, 28(3): 363-366.

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  An analysis is made to study the effect of inherent symmetry on the structures of the triply excited intrashell F and G states.
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  pn-Pair Avarage Velocity in Statistical Model of Photofission

  U. Lucial

  理论物理通讯. 1997, 28(3): 367-368.

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  A dassical statistical model of photofission is developed and as a consequence the pn-pair avarage velocity inside the nucleus is obtained.
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  The Characteristic Equation of q-Deformed Bosonic Oscillator

  WU Ning, RUAN Tunan

  理论物理通讯. 1997, 28(3): 369-372.

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  The main goal of this paper is to deduce the characteristic equation of [N]. From the fundamental relation of q-deformed bosonic oscillator, we deduce a strict algebraic equation. After introducing a moderate boundary condition, we obtain the characteristic equation of number operator [N].Using this equation, we extract all the eigenvalues of operator [N] and write out the corresponding eigenstates. Then we obtain the completeness of the Hilbert space.
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  Talmi-Moshinsky Transformat ion Brackets for Two-Dimensional Systems

  RUAN Wenying, LIU Youyan

  理论物理通讯. 1997, 28(3): 373-376.

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  An explicii formula for Talmi-Moshinsky transformation brackets for two-dimensional systems composed of arbitrary number of particles and arbitrary masses is presented, it is powerful in investigating the energy spectra and electron-electron correlations in the so-called artificial atoms.
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  Renormalization of Nucleon Self-Energy in Nuclear Matter by Dispersion Relation Method

  LIU Lianggang, XIE Wenfang, RUAN Wenying

  理论物理通讯. 1997, 28(3): 377-380.

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  Taking σ-exchange Fock term of nucleon self-energy in nuclear matter as an example, we renormalized the nucleon self-energy by both dimensional regularization method and dispersion relation method in the Walecka model. We compared them numerically and found them identical, independent of the renormalization methods.
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  The Applicability of Jeans Rule

  GAO Chongyi

  理论物理通讯. 1997, 28(3): 381-384.

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  Jeans rule has a wide applicability. It is not only applicable for the planets and satellites in the solar system, but also suitable for the asteroids, meteoroids and unusual outer solar system object 95P/Chiron. Its applicability can be expressed with nomogram as well as defined by equations or by figures.