标题： 十六极形变对轴向变形核的集体能谱的影响 显示英文标题

标题： Impacts of hexadecapole deformations on the collective energy spectra of axially deformed nuclei

摘要： 十六极形变以及四极形变都会影响有限核的低激发态。 十六极关联通常被大的四极效应所掩盖，因此尚未得到充分研究。 在这里，我们通过自洽平均场方法和相互作用玻色子近似的理论框架，探讨了在重核低能集体态计算中十六极形变的相关性。 明确包括四极和十六极集体自由度的相互作用玻色子哈密顿量，由能量密度泛函和配对相互作用的选择来确定。 在一个关于轴向变形的Gd同位素的说明性应用中，结果显示，引入十六极自由度不会对大多数低自旋和低激发态产生定性影响，但具有显著效果，因为它极大地改善了接近球形振动核基态带的高自旋态描述，并在高度变形核中产生了表现出强烈 $K^\pi=4^+$ 跃迁的 $E4$ 带。 显示英文摘要

摘要： The hexadecapole deformation, as well as the quadrupole one, influences the low-lying states of finite nuclei. The hexadecapole correlations are often overshadowed by the large quadrupole effects, and hence have not been much investigated. Here we address the relevance of hexadecapole deformations in the calculations of low-energy collective states of heavy nuclei, by using the theoretical framework of the self-consistent mean-field method and the interacting-boson approximation. The interacting-boson Hamiltonian that explicitly includes the quadrupole and hexadecapole collective degrees of freedom is specified by a choice of the energy density functional and pairing interaction. In an illustrative application to axially deformed Gd isotopes, it is shown that the inclusion of the hexadecapole degree of freedom does not affect most of the low-spin and low-lying states qualitatively, but that has notable effects in that it significantly improves the description of high-spin states of the ground-state bands of nearly spherical vibrational nuclei and gives rise to $K^\pi=4^+$ bands exhibiting strong $E4$ transitions in strongly deformed nuclei.