Semi-microscopic description of the double backbending in some deformed even-even rare earth nuclei

TL;DR

This paper introduces a semi-microscopic model to analyze double backbending phenomena in certain deformed rare earth nuclei, combining particle-core states and band mixing to explain observed moments of inertia anomalies.

Contribution

The paper presents a novel semi-microscopic approach that models backbending by mixing rotational bands built on particle-pair breaking states in deformed nuclei.

Findings

Successfully describes second anomaly in moments of inertia for four rare earth nuclei.

Demonstrates the effectiveness of band mixing in explaining backbending phenomena.

Provides a framework for future studies of nuclear rotational behaviors.

Abstract

A semi-microscopic model to study the neutron and proton induced backbending phenomena in some deformed even-even nuclei from the rare earth region, is proposed. The space of particle-core states is defined by the angular momentum projection of a quadrupole deformed product state. The backbending phenomena are described by mixing four rotational bands, defined by a set of angular momentum projected states, and a model Hamiltonian describing a set of paired particles moving in a deformed mean field and interacting with a phenomenological deformed core. The ground band corresponds to the configuration where all particles are paired while the other rotational bands are built on one neutron or/and one proton broken pair. Four rare earth even-even nuclei which present the second anomaly in the observed moments of inertia are successfully treated within the proposed model.