Signature-dependent triaxiality for shape evolution from superdeformation in rapidly rotating 40Ca and 41Ca

被引：5

作者：

Sakai, Shinkuro ^{[1
]}

Yoshida, Kenichi ^{[2
]}

Matsuo, Masayuki ^{[3
]}

机构：

[1] Niigata Univ, Grad Sch Sci & Technol, Niigata 9502181, Japan

[2] Kyoto Univ, Dept Phys, Kyoto 6068502, Japan

[3] Niigata Univ, Dept Phys, Niigata 9502181, Japan

来源：

PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS | 2020年 / 2020卷 / 06期

基金：

日本学术振兴会;

关键词：

OCTUPOLE EXCITATIONS; EFFECTIVE FORCES; SHELL-MODEL; STATES; NUCLEI; PARAMETRIZATION; VIBRATIONS; BANDS; S-32; LINE;

D O I：

10.1093/ptep/ptaa071

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We investigate the possible occurrence of highly elongated shapes near the yrast line in Ca-40 and Ca-41 at high spins on the basis of the nuclear energy-density functional method. Both the superdeformed (SD) yrast configuration and the yrare configurations on top of the SD band are described by solving the cranked Skyme-Kohn-Sham equation in the three-dimensional coordinate space representation. It is suggested that some of the excited SD bands undergo band crossings and develop to hyperdeformation (HD) beyond J similar or equal to 25h in Ca-40. We find that the change of triaxiality in response to rotation plays a decisive role in the shape evolution towards HD, and that this is governed by the signature quantum number of the last occupied orbital at low spins. This mechanism can be verified in an experimental observation of the positive-parity SD yrast signature-partner bands in Ca-41, one of which (alpha = +1/2) undergoes crossings with the HD band, while the other (alpha = -1/2) shows smooth evolution from collective rotation at low spins to non-collective rotation with an oblate shape at termination.

引用

页数：17