1989年, 第12卷, 第2期　
刊出日期：1989-09-15

  

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  Multiphonon Nonradiative Transition of RE³⁺ Ions in Ten Host Crystals¹

  WANG Zhao-qing, MA Dong-ping, ZHENG Xi-te, XU Yi-sun, ZHANG Zheng-gang

  理论物理通讯. 1989, 12(2): 127-136.

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  By using the formula of RE³⁺ multiphonon nonradiative transition (MPNRT) probability W_po derived on the basis of single-frequency model, the dependence of the W_po for the various RE ions in 10 hosts at the energy gap ΔE is analyzed and calculated systematically. The results agree well with a great deal of experimental data taken from the references and show clearly the characteristic of MPNRT under the condition of weak electron-phonon interaction: W_po decreases rapidly with the increase of order p which is the leading factor to determine W_po; the vahes of K. HUANG-Rhys factor S progressively increase in the order of halide-oxide-fluoride, and the values of S for the various hosts in the same group are close.
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  Finite Temperature Phase Diagram in the Half-Filled Extended Hubbard Model¹

  Jian ZHONG

  理论物理通讯. 1989, 12(2): 137-144.

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  The CDW-SDW transition in the half-filled extended Hubbard model is investigated with the broken-symmetry Hartree theory formulated in terms of the Bogoliubov variational approach. The finite temperature phase-diagram in the weak coupling regime is derived analytically with a model density of states. The results show that there exist charge-order and antiferromagnetic order, but no mixed phase exists at any temperatures.
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  Coupling Effect of Atomic Tunneling States with Local Vibration Modes in Amorphous Materials¹

  LIU Xiao, CHEN Hong, WU Xiang

  理论物理通讯. 1989, 12(2): 145-156.

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  Considering the coupling of the atomic tunneling states with the vibration modes of its nearby atoms, two different kinds of double-well potentials are obtained. At the meantime, the vibration of nearby atoms are softened, and under certain conditions a new double-wel1,potential of higher rank can be induced which makes a hierarchical double-well potential structure possible.
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  Hartree-Fock and Self-consist ent Semiclassical Approaches to the Properties of ²⁰⁸Pb

  LI Guo-qiang, XIANG Zhen-mao, GAO Qin

  理论物理通讯. 1989, 12(2): 157-165.

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  Based on the extended Skyrme force SKa and GS2, the Hartree-Fock and selfconsistent semiclassical calculations are carried out to investigate the static properties of ²⁰⁸Pb. The present results are compared with each other and with the experiments. A good agreement is obtained between two theoretical approaches and between theories and experiments.
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  Neutrinoless Double Beta Decay-A New Formalism

  CHING Cheng-rui, HO Tso-hsiu, WU Xing-rong

  理论物理通讯. 1989, 12(2): 167-178.

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  A new method-the operator expansion method is used in neutrinoless double beta decay processes. Both the neutrino mass and mixing of right-handed leptonic current are included. It is shown that for nuclear neutrinoless double beta decay in 2n mechanism, there appear some new terms besides the terms given by the conventional treatment based on closure approximation. The ββ with a Majoron emission is also discussed.
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  Coulomb Effect on Inelastic Scattering of Proton on Deformed Nuclei at High Energies

  ZHANG Yu-shun

  理论物理通讯. 1989, 12(2): 179-186.

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  In this paper, by using the collective coordinate of A. Bohr and phenomenological deformed optical potential and Coulomb interaction, the scattering amplitude of two composite particle systems can be obtained. The differential cross sections for the 0⁺, 2⁺, 4⁺ and 6⁺, p(0.8 GeV)+¹⁵⁴Sm and p (0.8 Gev)+¹⁷⁶Yb are calculated. The results show that the Coulomb effect is quite important.
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  The Effective Hamiltonian for Nonleptonic Decay with Possible m_t >mw and the ΔI=1/2 Rule

  Chao-hsi CHANG, Yuan-ben DAI, Xue-qian LI

  理论物理通讯. 1989, 12(2): 187-200.

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  The effective Hamiltonian for nonleptonic decays of strange, charm and beauty, involving the QCD corrections at short distances but with possible t quark mass m_t > mw and a correction of the initial value for the renormalization group equations, is computed in the framework of the operator product expansion (OPE). The numerical results show that our calculation gives corrections in right direction for approaching to the Δ1=1/2 rule and if using the latest experimental measurements on δ and ε'/ε for system as input, the KM parameter ε₂² would be constrained in a reasonable region (2.5～22.5)×10^-3.
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  One Way to Solve the Puzzle of γ5 in the Dimensional Regularization

  AN Ing, He-shan SONG

  理论物理通讯. 1989, 12(2): 201-208.

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  By calculating the Dirac matrices in four dimensions and performing the dimensional regularization for loop momentum integration variables, various Ward identities can be obtained straightforwardly and the puzzle for extending γ5 to n dimensions can be solved.
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  Casimir Effect of Scalar Field on S_n-1 Manifold

  XUE She-sheng

  理论物理通讯. 1989, 12(2): 209-218.

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  Casimir effect of scalar field on R⁴×S_n-1 manifolds is evaluated. The results show that compactness of manifolds S₁ and S₂ can be held by Casimir force. However, other compact spaces (S_n-1, n > 3 ) are unstable.
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  Normally Ordered and Antinormally Ordered Expansions of Some Exponential Operators in Hilbert Space

  FAN Hong-yi

  理论物理通讯. 1989, 12(2): 219-227.

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  In this paper, the completeness relations of the fundamental representations in quantum mechanics, together with the "integration within orderd product" technique are exploited to derive normally ordered and antinormally ordered expansions of some exponential operators in Hilbert space. Applications of the normally ordered exponential operators to evaluating Feynman matrix element in coherent state representation are given, which seems to be a new approach.
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  The Generalized Moment Analysis (GMA) and Spin Analysis for Boson Resonances

  YU Hong

  理论物理通讯. 1989, 12(2): 229-237.

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  Our analyais^[1] has shown that there exist sensitive and insensitive regions to determine the spin (J = 2 or 4) of ξ(2230) in the general helicity formalism. Whereaa it just falls into the insensitive region by using current data of ξ. If the number of events is not sufficient it is difficult to determine the spin of ξ^[2]. In this paper we generalize the moment analysis^[3]. We define the photon angular distribution H_J(θ_τ, LM) for the moment of process e⁺ +R^- → J/ψ → τ + ξ, ξ → p + p and the weighted moment by choosing appropriate weight function. They provide an effective criterion to determine the spin of ξ. We also use the method to discuss LIE puzzle for process e⁺ + e^- → J/ψ → τ + B₁ B → P₁ + P₂ + P₃.
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  Chou-Yang Model and Pion-Nucleus Elastic Scattering at High Energies

  Fazal-e-Aleem, Mohammad Saleem, Muhammad Rafique

  理论物理通讯. 1989, 12(2): 239-248.

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  The Chou-Yang model has been used to explain, in the diffraction peak region, the differential cross section and the slope parameter for the pion-deuteron and the pionhelium elastic scattering at high energies.