Study on Novel Quadrupole Collective States in Neutron-Rich Medium-Heavy Nuclei

在核壳模型的基础上，我们研究了Sm同位素的轴对称形变和丰中子Xe、Ba同位素的三轴形变态的核结构。在中重核中，由于希尔伯特空间的巨大规模，利用Lanczos方法的传统对角化方法是不可行的。为了克服这一困难，我们将准粒子真空基的蒙特卡罗壳层和能量方差外推方法应用于斯莱特行列基的蒙特卡罗壳层模型，并证明了它们在研究中重核的核结构方面有很好的效果，其中配对关联是非常重要的。

We studied the nuclear structure of axially symmetric deformation of samarium isotopes and tri-axially deformed states of neutron-rich xenon, barium isotopes based on the nuclear shell model. In medium-heavy nuclei, the conventional diagonalization method utilizing the Lanczos method is infeasible due to the huge size of the Hilbert space. In order to overcome this difficulty, we applied the Monte Carlo shell with quasi-particle-vacuum basis and the energy-variance extrapolation in the Monte Carlo shell model with Slater-determinant basis, and demonstrated that they work well in studying the nuclear structures of medium-heavy nuclei in which the pairing correlation is important.