Ba同位素链偶-偶核基态形状研究

采用反射不对称的相对论平均场模型,研究Ba同位素链的偶-偶核的结合能、四极形变、八极形变和电荷半径等性质.理论计算结果较好地符合了已有的实验数据.结果显示,原子核的四极形变随着质量数(A=126~174)的增长呈现从长椭球到近球形再到长椭球的转变.原子核的八极形变主要出现于A=144~154的范围.对原子核的电荷半径与质量数的依赖关系进行了研究,研究表明,在A=138附近,由于中子满壳(中子数N=82)的存在,电荷半径的增长曲线斜率出现明显变化.

Shapes of even-even Ba nuclei at ground states

The binding energies,quadrupole deformations,octupole deformations and charge radii of even-even Ba nuclei were investigated systematically.The calculated results are in good agreement with the available experimental data.It is found that the shapes for the nuclei change from prolates shape to near-spherical shapes,then to prolate shape again with the increase of the mass number (A=126～174).It is also found that the octupole deformations may exist mainly in region A=144～154.The dependence of nuclear charge radii on the mass number was also investigated.At A=138,the slope of the charge radii as a function of the mass number changes significantly because of the existence of the neutron number N=82.