Quantum self-organization and nuclear collectivities

TL;DR

This paper introduces quantum self-organization as a key mechanism in nuclear many-body systems, showing how it influences nuclear structure and collective phenomena beyond simple models, especially in heavier nuclei.

Contribution

It proposes the concept of quantum self-organization in nuclei, demonstrating its role in shaping single-particle energies and collective modes, and extends its relevance to other quantum systems.

Findings

Quantum self-organization affects nuclear structure and collective modes.

It explains phenomena like shape coexistence and quantum phase transitions.

Self-organization effects are more significant in heavier nuclei.

Abstract

The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems, for instance, atomic nuclei. It is shown that atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naive Fermi liquid picture. Nuclear forces are demonstrated to be rich enough to change single-particle energies for each eigenstate, so as to enhance the relevant collective mode. When the quantum self-organization occurs, single-particle energies can be self-organized (or self-optimized), being enhanced by (i) two quantum liquids, e.g., protons and neutrons, (ii) two major force components, e.g., quadrupole interaction (to drive collective mode) and monopole interaction (to control resistance). Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. Actual cases such as shape coexistence, quantum phase transition, octupole vibration/deformation, super deformation, etc. can be studied with this scope. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger. With larger numbers of them, the effects of the organization can be more significant. The quantum self-organization is a general phenomenon, and is expected to be found in other quantum systems.