Eur. Phys. J. A (2011) 47: 34
https://doi.org/10.1140/epja/i2011-11034-3

Regular Article - Theoretical Physics

Multiple reflection-asymmetric-type band structures in ²²⁰Th and dinuclear model

¹ Joint Institute for Nuclear Research, 141980, Dubna, Russia
² Institut für Theoretische Physik der Justus-Liebig-Universität, D-35392, Giessen, Germany

Received: 13 July 2010
Accepted: 3 February 2011
Published online: 10 March 2011

Abstract

The negative-parity bands with different values of K in ²²⁰Th are analysed within the dinuclear system model which was previously used for describing the ground-state alternating-parity bands with K = 0 in deformed actinides. The model is based on the assumption that the cluster type shapes are produced by the collective motion in the mass-asymmetry coordinate. To describe the reflection-asymmetric collective modes characterized by the nonzero values of K , the intrinsic excitations of clusters are taken into account. The observed excitation spectrum, angular-momentum dependence of the parity splitting and the staggering behaviour of the B(E1)/B(E2) ratios are explained.