1994年, 第22卷, 第2期　
刊出日期：1994-09-15

  

• 全选
  |

• Select
  High-Order Theory of Rearrangement Collision in an Intense External Field

  Ji CHEN, Yao-Yang LIU

  理论物理通讯. 1994, 22(2): 129-134.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  In this paper, the high-order perturbation theory for rearrangement collision in the presence of an intense external field is derived. An extended Kroll-Watson formulg for high-order rearrangement collision is obtained. The results suit any three-body rearrangement collision and any form of two-body interaction potential. The low-and high-frequency approximations are discussed.
• Select
  Path Integral Approach to the Propagator for a Charged Particle in a Time-Dependent Electromagnetic Field

  Jing-Bo XU, Yu-Jun ZHAO, Xiao-Chun GAO

  理论物理通讯. 1994, 22(2): 135-138.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  A path integral method is used to study the time evolution of a three-dimensional timedependent system. The propagator for a charged particle in a time-dependent magnetic field and quadrupolar electric potential is obtained.
• Select
  A CDW Model for MX Complexes: Hartree-Fock Scheme of Ground State

  Rong-Tang FU, Qing-Feng HUANG, Xin SUN, Rou-Li FU

  理论物理通讯. 1994, 22(2): 139-144.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  We study the effects of screened Coulomb electron-electron interactions in halogen-bridged. mixed-valence transition metal linear chain complexes (MX chains) applying lattice model with a double-well potential to simulate CDW ground state. With the periodicity of MX chain, we construct a complete set of orthogonal and normalized wave functions in view of the second-neighbor approximation. Starting from the restricted Hartree-Fock scheme, we diagnolize the Fock matrix analytically and calculate the LCAO-MO-SCF solutions. Our theory shows the dependence of charge transfer on the strength and screened coefficient of electron-electron interaction.
• Select
  The Critical Points of a Generalized Mixed Spin Model with Free Fermion Approximation

  Fu-Gao WANG, Wen-Yan JIA, Jia-Zhen HU

  理论物理通讯. 1994, 22(2): 145-150.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  A generalized mixed spin model with anisotropic interactions is considered on the union jack lattice. We find that the model is equivalent to a free fermion model. The critical temperature is obtained. In special cases, we get the same results as exact solutions.
• Select
  Thermal Shift Calculations (Ⅱ): The Theoretical Calculation of R Line Thermal Shift of MgO:Cr³⁺

  Dong-Ping MA, Xiao-Yi HUANG, Ju-Rong CHEN, Ji-Ping ZHANG

  理论物理通讯. 1994, 22(2): 151-160.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  By making use of the theory for thermal shift of crystal field spectra of rare earth or transition metalions, taking into account all the contributions adequately, we calculated R line thermal shift of MgO:Cr³⁺ by fitting experimental data. The results show a good agreement with thermal shift experimental data and a series of other experimental data of MgO:Cr³⁺. Values of the most important parameters are calculated theoretically with wavefunctions obtained from diagonalization of complete d³ energy matrices. They are in good agreement with those from fitting experimental data.
• Select
  Ground State of Triangular Heisenberg Antiferromagnet with a General Bose Transformation

  Chen-Geng WEI, Rui-Bao TAO

  理论物理通讯. 1994, 22(2): 161-166.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The spin-1/2 antiferromagnetic Heisenberg mode (AFHM) is investigated on the triangular lattice by using a general Bose transformation for magnetic system. We considered both thedynamical and kinematical interactions. Our calculation of the ground state energy showssome evidence which is favorable for the absence of sublattice long-range order on triangularLattice.
• Select
  The Stochastic Adiabatic Approximation in a System Driven by Additive O-U Noise or Dichotomous Noise

  Jing-Hui LI, Shu-Shan XU, Li CAO, Da-Jin WU

  理论物理通讯. 1994, 22(2): 167-172.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  We study a set of nonlinear stochastic equations describing a large class of nonlinear mul-tidimensional non-Markovian dynamical systems driven by additive O-U noise, and a classof nonlinear multidimensional differential equations driven by dichotomous noise. By virtueof the stochastic generalization of usual adiabatic approximation, the equations for the orderparameters are obtained. The statistical properties of the new stochastic variables arestudied.
• Select
  Hamiltonian Formalism for the NLS Equation with Nonvanishing Boundary Condition

  Zong-Yun CHEN, Nian-Ning HUANG

  理论物理通讯. 1994, 22(2): 173-182.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  For the NLS equation with nonvanishing boundary condition, Hamiltonian formalism is developed. Together with two previous works, the results obtained are in the same level as those obtained for the NLS equation with vanishing boundary condition.
• Select
  Similarity Reductions for the Davey-Stewartson Equations Using a Direct Method

  Wei-Zhong CHEN

  理论物理通讯. 1994, 22(2): 183-186.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  By the direct method that involves no group theory, the Davey-Stewartson equations (DSE's)in (2+1) dimensions have been reduced to some (1+1)-or 2-dimensional partial differentialequations which have included all the types of symmetry reductions using the standard Liegroup theory. As a special case we obtained the 1-dimensional reducing equations fromDSE's in (2+1) dimensions directly.
• Select
  The Reliability of the Fitted Parameters in Pion Interferometry

  Q. H. ZHANG, W. Q. CHAO

  理论物理通讯. 1994, 22(2): 187-192.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The correlations among the radius, lifetime and coherent parameter of the pion source in high energy heavy-ion collisions are analyzed. The effects of q₀ cuts on the radius are studied. The reason why the data of 4π detector is not sensitive to the lifetime is also discussed.
• Select
  The Effective Mass of Sigma Meson at Finite Temperature and Density

  Ru-Keng SU, Wan-Heng ZHONG, Zhi-Xin QIAN

  理论物理通讯. 1994, 22(2): 193-198.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  By means of the finite temperature and finite density real time Green's function method, the effective mass of sigma meson is calculated by summing the bubble diagrams. It is found that the formula of effective mass given by ρ meson can also be used to describe the sigma meson, but the parameter n depends on density. The conjecture of Brown and Rho about the effective mass of meson can well be proved by quantum field theory in high temperature region.
• Select
  Investigation of U(1) Lattice Gauge Model at Finite Temperature to Higher Order Expansion

  Xi-Te ZHENG, Yuan HE, Zhao LU

  理论物理通讯. 1994, 22(2): 199-206.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The cumulant expansion of U(1) lattice gauge model at finite temperature (N_T=1) to the sixth order is presented. The variational parameters are determined by requiring thatthe corrections to the zeroth order approximation are the smallest. The order parameter,Polyakov line , converges well and is in good agreement with Monte Carlo simulations.Especially, the deconfinement phase transition point can be determined with accuracy.
• Select
  Padé Improvement of Beta-Function in Perturbative λØ⁴ and QED

  Ji-Feng YANG, Guang-Jiong NI

  理论物理通讯. 1994, 22(2): 207-212.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Padé Approximants are applied to the β-functions given in perturbative forms in λØ⁴ and QED in order to improve their convergence and to go beyond perturbation. Then we integrate the β-functions to find the solutions of the effective coupling constants. Some discussions on the results are given.
• Select
  Relativistic Generalization of Many-Body Correlation Dynamics

  Wei ZUO, Hua GUO, Shun-Jin WANG

  理论物理通讯. 1994, 22(2): 213-218.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  With the aid of generating-functional technique, the many-body correlation dynamics wasgeneralized to the relativistic cases within a Green's function formalism and two sets of equations of motion for the correlation (or connected) Green's functions were derived respectively for the scalar س-model and the Yukawa model, which were nonperturbative in nature and could provide physically transparent truncations with respect to the order of correlations.
• Select
  A Study on the Quark Potential Derived from QCD and Application to cc system

  Gang LI, Xue-Qian LI, Peng-Nian SHEN

  理论物理通讯. 1994, 22(2): 219-232.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Incorporating the nonpkrturbative effects of QCD, an effective potential with confinementterms is derived. With it, we calculate the spectrum of the cc family and also evaluateΓ_e+e-,1³ P_J splitting and the electromagnetic transition rates. The results show that as theBorelization is taken, one can obtain values which are roughly consistent with experimentaldata, whereas without the Borelization the values are quite apart from the data. In theprocess of calculations, there are few free parameters, therefore the obtained results are ofsignificance for understanding the underlying theory of the potential model.
• Select
  Instability of the Negaoka States in the Thermodynamic Limit

  C. C. WAN

  理论物理通讯. 1994, 22(2): 233-236.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  We study the infinite U Hubbard model on a square lattice. By introducing a transformationwhich transforms the up spin and down spill fermions in to two families of bosons with phasefactors, we show that the fully ferromagnetic state is not the ground state at any finite holeconcentration.
• Select
  Statistical Distribution of q-Bosonic Oscillators

  Dong MI, He-Shan SONG, Ing AN

  理论物理通讯. 1994, 22(2): 237-240.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The statistical distribution for a system of q-deformed harmonic oscillators is studied and an explicit form of q-dependence of the distribution function is given. The physical meaning of the deformation parameter q is discussed.
• Select
  On Several Equivalent Descriptions of the Self-Dual Yang-Mills Integrable System

  Jing-Fa LU, Mi XIE

  理论物理通讯. 1994, 22(2): 241-244.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  In this short communication we show that the new Lax pair for SDYM theory can be derivedfrom prolongation approach and some equivalent expressions for SDYM integrable theoryare given by the "gauge" transformation.
• Select
  New Similarities of the Fifth Order KdV Equation

  Jie-Fang ZHANG, Hui-Dan YU

  理论物理通讯. 1994, 22(2): 245-248.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Using the method introduced by Clarkson and hiuskal (CK) recently, we obtain the similarity reductions of the fifth order KdV equation, and give some discussions of special casesat last.
• Select
  A New Realization of Quantum Algebra SU_q(2) in Terms of the Basis of Lie Algebra su(2)

  Sheng-Li ZHANG, Yi-Shi DUAN

  理论物理通讯. 1994, 22(2): 249-252.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  In this letter, we present a set of new formulas of three q-generators of quantum algebraSU_q(2), which are the nonlinear combination of the basis elements of Lie algebra su(2). Inthe limit q → 1, these q-generators contract to the quantities that satisfy the commutationrelation of Lie algebra su(2).
• Select
  Some New Completeness Relations in Multi-Mode Fock Space

  Hong-Yi FAN

  理论物理通讯. 1994, 22(2): 253-256.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Using the technique of integration within an ordered product (IWOP) of operators we findsome new continuum state vectors which span completeness relations in niulti-mode Fockspace. This fact tells us that the representation theory in quantum mechanics need to bestudied in more detail.