Softness of Nuclear Matter and the Production of Strange Particles in Neutron Stars

In the various models,we study the influences of the softness of nuclear matter,the vacuum fluctuation of nucleons and σ mesons on the production of strange particles in neutron stars,We find that the stiffer the nuclear matter is,the more easily the strange particles is produced in neutron stars.The vacuum fluctuation of nucleons has large effect on strange particle production while that of σ meson has little effect on it.     

Tachyon Pole in σ Meson Propagator in Nuclear Matter in the Relativistic σ—ω Model

The conditions that the tachyon pole of the σ meson propagator in nuclear matter appears are studied in the one-loop approximation in the relativistic σ-ω model.Different from the results of the previous paper,we find that the effect of the constant a in the self-interaction,U(σ)=aσ 1/2! bσ^2 1/3!cσ^3 1/4!dσ^4,of the σ meson cannot be neglected.It determines the critical density where techyon appears.The smaller the a,the larger the critical density.The binding energy,pressure,incompressibility coefficient,nucleon effective mass are calculated and the relation between parameters to the tachyon pole is also studied.     

Features in Quasi—particle Excitations and Tunnelling Spectra due to Coupling to Spin Fluctuations in High—Tc Cuprates

In a self-consistent mean-field treatment of the two-dimensional t-t‘-J model,we theoretically examine the coupling of in-plane quasi-particles to the antiferromagnetic spin fluctuations in high-Tc superconductors,which renormalizes the fermionic self-energy.We reproduce the characteristic peak-dip-hump structure observed not only in angly-resolved photoemission spectroscopy,but also in superconductor-insulator-normal metal unctions and scanning tunnelling microscopy experiments.We consider the evolution of this structure with doping.It is shown that this kind of coupling can account for many anomalous properties of high-Tc superconductors in superconducting states.     

Density Dependence of the Mass and Decay Constant of Pion in Nuclear Matter in the Dyson-Schwinger Equation Approach of QCD

With the Dyson-Schwinger equation formalism at finite chemical potential, we study the density dependence of the mass and decay constant of pion in nuclear matter. The calculated results indicate that both the mass and the decay constant remain almost constant at small chemical potential. As the chemical potential gets quite large, the decay constant increases and the mass decreases with the increasing of the chemical potential, and both of them vanish suddenly as a critical value is reached.     

Pseudoscalar Cornell potential for a spin- 1/2 particle under spin and pseudospin symmetries in 1 ＋ 1 dimension

The Cornell potential that consists of Coulomb and linear potentials has received a great deal of attention in particle physics. In this paper, we present the exact solutions of the Dirac equation with the pseudoscalar Cornell potential under spin and pseudospin symmetry limits. The energy eigenvalues and corresponding eigenfunctions are given in closed form.