Model for collective motion

TL;DR

This paper reviews the concept of collective motion in nuclei, introduces a simple model for large-amplitude shape dynamics, and discusses modern microscopic implementations that accurately describe nuclear excitations and fission.

Contribution

It presents a simple model for collective nuclear motion and discusses its integration with modern energy density functional methods.

Findings

The model describes quadrupole and octupole shape dynamics effectively.

Results align well with experimental data on nuclear excitations.

Modern implementations provide accurate global descriptions of nuclear states.

Abstract

Collective motion is a manifestation of emergent phenomena in medium-heavy and heavy nuclei. A relatively large number of constituent nucleons contribute coherently to nuclear excitations (vibrations, rotations) that are characterized by large electromagnetic moments and transition rates. Basic features of collective excitations are reviewed, and a simple model introduced that describes large-amplitude quadrupole and octupole shape dynamics, as well as the dynamics of induced fission. Modern implementations of the collective Hamiltonian model are based on the microscopic framework of energy density functionals, that provide an accurate global description of nuclear ground states and collective excitations. Results of illustrative calculations are discussed in comparison with available data.