Microscopic description of quadrupole-octupole coupling in Sm and Gd isotopes with the Gogny Energy Density Functional

TL;DR

This paper investigates the coupling between quadrupole and octupole deformations in Sm and Gd isotopes using the Gogny Energy Density Functional, analyzing their effects on various physical properties at the mean field level and beyond.

Contribution

It introduces a detailed microscopic analysis of quadrupole-octupole coupling in Sm and Gd isotopes with advanced beyond-mean-field methods using the Gogny functional.

Findings

Quadrupole-octupole coupling is weak in the studied isotopes.

Negative parity states are mainly described by octupole deformation.

The model reproduces experimental excitation energies and transition probabilities.

Abstract

The interplay between the collective dynamics of the quadrupole and octupole deformation degree of freedom is discussed in a series of Sm and Gd isotopes both at the mean field level and beyond, including parity symmetry restoration and configuration mixing. Physical properties like negative parity excitation energies, E1 and E3 transition probabilities are discussed and compared to experimental data. Other relevant intrinsic quantities like dipole moments, ground state quadrupole moments or correlation energies associated to symmetry restoration and configuration mixing are discussed. For the considered isotopes, the quadrupole-octupole coupling is found to be weak and most of the properties of negative parity states can be described in terms of the octupole degree of freedom alone.