Multiple reflection-asymmetric type band structures in $^{220}Th$ and dinuclear model

TL;DR

This paper investigates negative parity bands in $^{220}Th$ using a dinuclear system model that accounts for reflection asymmetry and cluster excitations, explaining parity splitting and transition ratios.

Contribution

It applies the dinuclear model to describe reflection-asymmetric band structures in $^{220}Th$, incorporating cluster intrinsic excitations for the first time.

Findings

Successfully reproduces angular momentum dependence of parity splitting.

Explains staggering behavior of $B(E1)/B(E2)$ ratios.

Provides insight into reflection-asymmetric collective modes.

Abstract

The negative parity bands in $^{220}$Th are analyzed within the dinuclear system model which was previously used for describing the alternating-parity bands in deformed actinides. The model is based on the assumption that cluster type shapes are produced by the motion of nuclear system in the mass-asymmetry coordinate. To describe the reflection-asymmetric collective modes characterized by nonzero values of $K$, the intrinsic excitations of clusters are taken into account. The angular momentum dependence of the parity splitting and the staggering behavior of the $B(E1)/B(E2)$ ratios as functions of angular momentum are explained.