1998 Vol. 22, No. 2
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The channels of J/ψ decay into,ΛΛ,ΛΛγ and ΛΛπ0 are analyzed with 7.8×106 J/ψ events collected by BES detector at BEPC Collider.The branching ratios for three channels and the angular distribution for the first channel are measured.The branching ratios are Br(J/ψ→ΛΛ)=(l.08±0.06±0.24)×10－3,Br(J/ψ→ΛΛγ)
A new formula about the momentum distribution width σ of relativistic heavy ion fragments can be obtained by equally dividing the number of nucleons A in the fragmenting nucleus into groups and using the result derived by H Feshbach and K. Huang. The new formula can explain the quantity of fragments which mass number K≤A/2.
For quantum systems with semi-simple Lie algebraic structures,the exact solutions of the equations of motion are obtained by means of algebraic dynamics.The Hamiltonian is transformed into a linear function of Cartan operators by a set of gauge transformations. The coefficients of the gauge transformations are determined by a set of ordinary differential equations.From the inverses of these gauge transformations,the solutions of the Schrodinger equation,as well as a set of dynamic constants of motion (dynamic invariant operators) are obtained. An SU(3) model serves as an example.
The leading term of qantum Wilson loop for Stelle gravity is calculated. The qantum result of vector papallel transport is obtained using the excitation of curvature, and a functional expression for calculating the quantum Wilson loop under the nonflat background is presented.
We study the distribution of intermittency exponents of a single event inhigh energy collisions. The relations between intermittency and the number of phasespace intervals and multiplicity are obtained. A proper requirement is obtained forcorrectly studying the dynamical fluctuation of a singe event with neglegble influenceof statistical fluctuations.
The kinds of infrared divergent integrals in three-loop vacuum graghs of gluon field at finite temperature are pointed out and their regularization is discussed. All of the infrared divergences in three-loop vacuum graghs of gluon field are isolated.
The coupling effect of (N) channel on the N-N scattering is studied by solving a coupled channel RGM(Resonating Group Method) equation in the quark-SU(3) chiral model. The results indicate that the coupling between 1S0 (NN) and 5 D0 (N) is important in explaining the NN 1S0 phase shifts, and the influence of the (N) channel coupling to the N-N higher partial wave scattering is small.
The dynamical process in heavy ion collisions at intermediate energy described by Two-Body Correlation Transport Theory (TBCTT) under different hierarchy truncation is discussed. It is found that the different hierarchy truncations of TBCTT have different descriptions about the dynamical process of heavy ion collision.
We study the method which directly adopts the azimuthal angles and the rotation angle of the axis to describe the evolving process of the angular momentum eigenstates under the space rotation transformation we obtain the angular momentum rotation and multi-rotation matrix elements ' path integral which evolves with the parameter λ(0→θ,θ the rotation angle), and establish the general method of treating the functional (path) integral as a normal multi-integrals.
The collective states in,110Cd are discussed with the proposed concept of dynamical correlation, while the g-boson degree of freedom is also considered, The octopole state is discussed in the frame of sdf boson model.
A microscopic framework of sdlBM-2 is extended to the one of sdglBM-2. lntroducing hexadecupole pairing force, Hamdltonian and E2,E4 operators of the sdglBM-2 are deduced microscopically. The nucleus 24Mg in the light-mass region is chosen as the first application of such an extended microscopic approach. Based on strong coupling picture, spectrum, reduced E2 transition rates and reduced E4 transition matrix elements are calculated. The calculated results fit experimental results quitewell.
The closed orbit distortion (COD) and its correction in the presence of field and alignment errors of magnets, for the heavy ion cooling storage ring (named CSRm), have been simulated on the basis of linear lattice of CSRm. ln a typical case, the maximurn COD before correction is 3.08mm and 2.73mm for horizontal plane and vertical plane, respectively. The simulation shows that the COD of CSllm can be limited with in a sufficiently small range.
We described the design of the measuring system for soft X-ray absolute intensity in detail. The system consists of two parts:: the ionization chamber and the monitoring (or, to be calibrated) detector and its transfering system. The system can be used as the primary standard detector for the measurement of soft X-ray absolute radiation flux in the energy range from 50 to 2000eV after alibrated. The uncertainty of the system is also given.
The feasibility of total reflection X.ray .fluorescence spectrometer applied in the biomedical field is discussed. With this spectrometer, the normal and radiated small intestine cells of small white mice were analyzed. The results indicate that the content of trace elements for normal and radiated small white mice was greatly different which can be used to provide valuable clue for clinic medicine.
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