反射不对称自由度对原子核基态性质的影响

Influences from reflection asymmetric degree of freedom on the ground state properties of nuclei

采用反射不对称相对论平均场(Reflection Asymmetric Relativistic Mean Field,RAS-RMF)理论研究了226Th和216Th原子核的基态性质.通过改变RAS-RMF理论计算中双中心谐振子基的不对称系数δ3、形变参数δ2以及基大小参数N,探讨了基参数的变化对计算结果的影响.结果表明:双中心谐振子基参数的改变对RAS-RMF计算结果都存在稳定的区间,在这个稳定区间里,RAS-RMF计算结果与实验数据以及有限力程小液滴模型(FRDM)计算结果一致.尤其是反射不对称自由度的引入,改进了相对论平均场的理论计算,给出了与实验更加符合的结果,表明RAS-RMF理论对描述具有反射不对称形变的原子核更具优越性.

The ground state properties for the nuclei 226Th and 216Th are investigated by the Reflection Asymmetric Relativistic Mean Field（RAS-RMF） theory,which is calculated by an expansion method with the two-center harmonic oscillator wavefunctions adopted as the basis.The calculated binding energies and deformations are checked to vary with the parameters of basis,which include the reflection asymmetry parameter δ3,the deformation parameter δ2,and the size of basis N.The results show that there is an interval for every parameter,where the RAS-RMF calculations are stable and almost unchanged with the value of parameter.In the intervals of parameters,the RAS-RMF calculations agree the experiment as well as the Finite-Range small Droplet Model（FRDM） very well.In particular,the introduction of the reflecting asymmetric degree of freedom improves the RMF calculations,and presents a better description for the nuclei possessing reflection asymmetric deformation.