Microscopic description of quadrupole-octupole coupling in neutron-rich actinides and superheavy nuclei with the Gogny-D1M energy density functional

TL;DR

This paper investigates the coupling between quadrupole and octupole deformations in neutron-rich actinides and superheavy nuclei using advanced mean-field and beyond-mean-field methods with the Gogny-D1M functional, revealing weak coupling effects.

Contribution

It introduces a detailed microscopic analysis of quadrupole-octupole interactions in heavy nuclei using parity restoration and generator coordinate methods with the Gogny-D1M functional, highlighting the dominance of octupole effects.

Findings

Quadrupole-octupole coupling is weak in studied nuclei.

Negative parity states are well described by octupole degrees of freedom.

Correlation energies and transition probabilities are quantitatively analyzed.

Abstract

The interplay between quadrupole and octupole degrees of freedom is discussed in a series of neutron-rich actinides and superheavy nuclei with $92 \le$ Z $\le 110$ and $186 \le$ N $\le 202$. In addition to the static Hartree-Fock-Bogoliubov approach, dynamical beyond-mean-field correlations are taken into account via both parity restoration and symmetry-conserving Generator Coordinate Method calculations based on the Gogny-D1M energy density functional. Physical properties such as correlation energies, negative-parity excitation energies as well as reduced transition probabilities $B(E1)$ and $B(E3)$ are discussed in detail. It is shown that, for the studied nuclei, the quadrupole-octupole coupling is weak and to a large extent the properties of negative parity states can be reasonably well described in terms of the octupole degree of freedom alone.