Nonlocalized Clustering: A New Concept in Nuclear Cluster Structure Physics

TL;DR

This paper demonstrates that nonlocalized alpha clustering, modeled with the THSR wave function, accurately describes nuclear cluster states in ene, challenging traditional localized cluster models and revealing clusters as delocalized entities within nuclei.

Contribution

It introduces the use of a single nonlocalized THSR wave function to successfully describe inversion-doublet band states in ene, showing high overlaps with exact solutions and challenging traditional localized cluster views.

Findings

Nonlocalized THSR wave functions describe cluster states with over 99% overlap.

Clusters are delocalized and move freely within the nucleus.

Results challenge the traditional localized cluster model in nuclear physics.

Abstract

We investigate the $\alpha$+\oo\ cluster structure in the inversion-doublet band ($K^\pi=0_{1}^\pm$) states of \nene\ with an angular-momentum-projected version of the Tohsaki-Horiuchi-Schuck-R\"{o}pke (THSR) wave function, which was successful "in its original form" for the description of, e.g., the famous Hoyle state. In contrast with the traditional view on clusters as localized objects, especially in inversion doublets, we find that these {\it single} THSR wave functions, which are based on the concept of nonlocalized clustering, can well describe the $K^{\pi}=0_1^-$ band and the $K^{\pi}=0_1^+$ band. For instance, they have 99.98% and 99.87% squared overlaps for $1^-$ and $3^- $ states (99.29%, 98.79% and 97.75% for $0^+, 2^+$ and $4^+$ states), respectively, with the corresponding exact solution of the $\alpha$+\oo\ resonating group method. These astounding results shed a completely new light on the physics of low energy nuclear cluster states in nuclei: The clusters are nonlocalized and move around in the whole nuclear volume, only avoiding mutual overlap due to the Pauli blocking effect.