Quadrupole collectivity in random two-body ensembles

TL;DR

This paper investigates how collective nuclear behaviors, especially quadrupole collectivity, emerge from random two-body interactions, revealing a dominant quadrupole component that leads to rotational spectra and deformed mean-field structures.

Contribution

It demonstrates that quadrupole coherence naturally arises in random two-body ensembles, leading to collective phenomena like deformation and rotation.

Findings

Quadrupole-quadrupole interaction dominates in random ensembles.

Rotational spectral features emerge from quadrupole coherence.

Deformed mean-field geometries are suggested by the results.

Abstract

We conduct a systematic investigation of the nuclear collective dynamics that emerges in systems with random two-body interactions. We explore the development of the mean field and study its geometry. We investigate multipole collectivities in the many-body spectra and their dependence on the underlying two-body interaction Hamiltonian. The quadrupole-quadrupole interaction component appears to be dynamically dominating in two-body random ensembles. This quadrupole coherence leads to rotational spectral features and thus suggests the formation of the deformed mean-field of a specific geometry.