A microscopic approach in appropriately truncated shell model was applied to the description of high spin states for <sup>162</sup>Hf and <sup>164</sup>Hf isotopes. For the description of high spin states, the model contained no additional free parameter. From the point of view of self-consistency, this is a remarkable advantage differing from the phenomenological work. The backbends of the moment of inertia were reproduced well by the calculation. The results show that the approach is able to investigate the yrast states of nuclei in rare earth region.
The parameters of the sdg interacting boson model Hamiltonian are calculated for the <sup>104-110</sup>Pd isotopes. The calculations utilize the microscopic procedure based on the Dyson boson mapping proposed by Yang-Liu-Qi and extended to include the g boson effects. The calculated parameters reproduce those values from the phenomenological fits. The resulting spectra are compared with the experimental spectra.
EUROPEAN PHYSICAL JOURNAL C,1995年66(3):473-484 ISSN：1434-6044
LUND UNIV,DIV COSM & SUBATOM PHYS,S-22362 LUND,SWEDEN.;CHINA UNIV GEOSCI,DEPT APPL GEOPHYS,WUHAN 430074,PEOPLES R CHINA.;[CAI, X] HUA ZHONG NORMAL UNIV,INST PARTICLE PHYS,WUHAN 430070,PEOPLES R CHINA.
[CAI, X] H;HUA ZHONG NORMAL UNIV,INST PARTICLE PHYS,WUHAN 430070,PEOPLES R CHINA.
A possible universal description of rapidity dependence of multiplicity distributions in high energy e(+)e(-), mu p, hh, hA and AA collisions is proposed based on a cluster mechanism, local charged compensation and its violation. It appears that there exist a statistical connection between multiplicity distribution in a full longitudinal phase space and that in a selected rapidity window with limited size.
INST HIGH ENERGY PHYS,ALMA ATA,KAZAKHSTAN.;ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING,PEOPLES R CHINA.;INST GRAVITAT & SPACE RES,BUCHAREST,ROMANIA.;PANJAB UNIV,DEPT PHYS,CHANDIGARH 160014,INDIA.;HUNAN EDUC INST,DEPT PHYS,CHANGSHA,PEOPLES R CHINA.
A radial-azimuthal stability analysis of a geometrically thin, gas-pressure-dominated accretion disk is presented. In the purely radial perturbation case, the disk is pulsationally unstable to the acoustic modes but stable to the thermal and viscous modes. If the coupling of radial and azimuthal perturbations is considered, the stability properties of the disk are different. With the increase of azimuthal wavenumber, the acoustic modes tend to become stable while the viscous mode becomes unstable. The acoustic instability exists only for large viscosity and small azimuthal wavenumber, while the viscous instability exists for small viscosity and large azimuthal wavenumber. The inclusion of azimuthal perturbations, however, has nearly no effect on the stability of thermal mode, which is always stable in the disk. The influence of opacity on the stability of a gas-pressure-dominated disk has also been investigated. We find that if the free-free absorption dominates the opacity, the disk is more stable than that with electron-scattering domination.
[HOU, DF] H;HUAZHONG NORMAL UNIV,INST PARTICLE PHYS,WUHAN 430070,PEOPLES R CHINA.
The effective potential of the Weinberg-Salam (WS) model is calculated at finite temperature and in the chemical potential of top quarks according to the grand canonical ensemble temperature field theory. The electroweak transition is studied at hot and density conditions. It is indicated that the symmetry restoring transition can take place either by increasing the temperature or chemical potential of top quarks, but at high temperature and in the low chemical potential the transition is of the first order, and it becomes the second order at a cold density condition. The phase diagrams are showed.