Hexadecapole axial collectivity in the rare earth region, a beyond mean field study

TL;DR

This study investigates hexadecapole collectivity and its interaction with quadrupole modes in rare earth nuclei using a beyond mean field approach, revealing strong coupling effects and vibrational nature of low-lying states.

Contribution

It provides the first detailed analysis of hexadecapole and quadrupole interplay using the HFB+GCM framework with various Gogny force parametrizations.

Findings

Strong coupling between quadrupole and hexadecapole degrees of freedom.

First two excited states are vibrational in character.

Prolate-oblate shape mixing influences hexadecapole state properties.

Abstract

Hexadecapole collectivity and its interplay with quadrupole degrees of freedom is studied in an axial symmetry preserving framework based on the Hartree Fock Bogoliubov (HFB) plus generator coordinate method (GCM). Results are obtained for several even-even isotopes of Sm and Gd with various parametrizations of the Gogny force. The analysis of the results indicates the strong coupling between the quadrupole and hexadecapole degrees of freedom. The first two excited states are vibrational in character in most of the cases. The impact of prolate-oblate shape mixing in the properties of hexadecapole states is analyzed.