Octupole correlation effects on two-neutron transfer intensity in rare-earth nuclei

TL;DR

This study investigates how octupole correlations affect low-lying states and two-neutron transfer intensities in rare-earth nuclei, revealing their significant role in nuclear shape phase transitions.

Contribution

It demonstrates that octupole degrees of freedom are crucial for accurately describing negative-parity states and transfer reactions in rare-earth nuclei within the interacting boson model.

Findings

Octupole correlations significantly influence two-neutron transfer intensities.

The model reproduces experimental discontinuities near N≈88-90.

Large numbers of low-energy 0+ states with octupole components are predicted.

Abstract

Impacts of octupole correlations on the low-lying $0^+$ states and two-neutron transfer intensities in rare-earth nuclei are investigated in terms of the interacting boson model that is based on the nuclear density functional theory. The octupole degrees of freedom are not only essential building blocks to describe properties of negative-parity states in the model, but also influence low-spin positive-parity states including excited $0^+$ states. The calculation produces a large number of low-energy $0^+$ states that contain significant amounts of octupole components, indicating important roles played by the octupole degrees freedom in this mass region. Octupole correlations are shown to make sizable contributions to the $(p,t)$ and $(t,p)$ transfer intensities and, in particular, to reproduce the discontinuous changes of these quantities near those nuclei with $N\approx88$ or 90, which are observed experimentally as a signature of the shape phase transition.