ρ介子的密度依赖性对有限核性质的影响

Influence of ρ meson density dependent behavior on properties of finite nuclei

利用等效的Dirac Brueckner Hartree-Fock方法,即用密度相关的核子-介子耦合常数在相对论平均场近似下,考虑了ρ介子的密度依赖行为,研究了有限核的性质。重新构建一组σ和ω介子密度依赖的耦合常数,并在此基础上给出ρ介子密度依赖的耦合常数,计算出双幻核16O,40Ca,48Ca,208Pb,所得到的每粒子平均结合能及电荷均方根半径更好的符合实验值。采用这套耦合常数,系统地计算了O,Ca,Pb,Zr核的基态性质,进行了详细的分析,并着重讨论了ρ介子的密度依赖性对Ca和Pb同位素链核性质的影响。考虑ρ介子的密度依赖性计算的有限核性质比没考虑的结果要好,尤其是对不对称核更明显。这套耦合常数不仅能很好的描述稳定核的性质,而且有利于对远离β稳定线核性质的研究。

A density dependent effective interaction in the relativistic Mean-Field （RMF） theory was adopted to reproduce the Dirac-Brueckner-Hartree-Fock （DBHF） results. We consider that the coupling constant of ρ meson is density dependent in the paper. We rebuild a set of coupling constants of ρ and to meson, and density dependent coupling constant of p meson is given. The properties of double-magic nucleus of 160, 4o Ca, 4s Ca and 208 Pb are calculated, and the binding energy per nucleon and rms radius of the charge are better fitted with the experimental value. With these coupling constants the ground state properties of O, Ca, Pb, Zr nuclei is given systematically, and focuse on the properties of the isotopes of Ca and Pb. It may conclude that consider the p meson density dependent behavior of the calculation result of the properties of finite nuclei is better than not to consider, and especially obvious for asymmetric nuclear. It can be used to describe very well the ground state properties not only stable, but also unstable nuclei without any free parameters.