The clustered nucleus—cluster structures in stable and unstable nuclei

Abstract

The subject of clustering has a lineage which runs throughout the history of nuclear physics. Its attraction is the simplification of the often uncorrelated behaviour of independent particles to organized and coherent quasi-crystalline structures. In this review the ideas behind the development of clustering in light nuclei are investigated, mostly from the stand-point of the harmonic oscillator framework. This allows a unifying description of alpha-conjugate and neutron-rich nuclei, alike. More sophisticated models of clusters are explored, such as antisymmetrized molecular dynamics. A number of contemporary topics in clustering are touched upon; the 3α-cluster state in 12 C, nuclear molecules and clustering at the drip-line. Finally, an understanding of the 12 C + 12 C resonances in 24 Mg, within the framework of the theoretical ideas developed in the review, is presented.

Cluster formations in deformed states forSi28andS32Ichikawa1, Kanada-En’yo2, Möller3 2011Phys. Rev. C299730View full textAdd to dashboardCite

“…PACS numbers: 21.10.-k, 21.60-n, 27.30.+t A rich variety of nuclear structure data in the s-d shell region provides an excellent opportunity to investigate how a system transitions between one-body-like mean-field and twobody-like cluster structures [1,2]. Because of recent progress in experimental techniques, it has been possible to determine that strongly deformed states exist in 36 Ar and 40 Ca, by the observation of γ-ray cascades typical of rotational bands [3,4].…”

New Horizons in Fundamental Physics

“…4 that displays axially and reflection symmetric self-consistent equilibrium nucleon density distributions. We note the well known quasimolecular α-12 C-α structure although clustering effects are less pronounced than the ones predicted by Nilsson-Strutinsky calculations and even by mean-field calculations (including Hartree-Fock and/or Hartree-Fock-Bogoliubov calculations) [5,6,7,58].…”

“…In particular, the extremely deformed rotational bands in 36 Ar (shown as crosses in Fig. 3 resonances belong to a rotational band, with a moment of inertia close to that of a HD band provided by both the cranked α-cluster model [5] and the Nilsson-Strutinsky calculations. The fact that similar quasi-molecular states observed in the two reactions fall on the same rotational band gives further support to our interpretation of the 36 Ar composite system resonances.…”

“…The question of how quasimolecular resonances may reflect continuous transitions from scattering states in the ion-ion potential to true cluster states in the compound systems was still unresolved in the 1990s [1]. In many cases, these resonant structures have been associated with strongly-deformed shapes and with α-clustering phenomena [5,6], predicted from the Nilsson-Strutinsky approach, the cranked α-cluster model [5], or other mean-field calculations [6,7]. In light α-like nuclei clustering is observed as a general phenomenon at high excitation energy close to the α-decay thresholds [5,8].…”

“…In many cases, these resonant structures have been associated with strongly-deformed shapes and with α-clustering phenomena [5,6], predicted from the Nilsson-Strutinsky approach, the cranked α-cluster model [5], or other mean-field calculations [6,7]. In light α-like nuclei clustering is observed as a general phenomenon at high excitation energy close to the α-decay thresholds [5,8]. This exotic behavior has been perfectly illustrated by the famous "Ikeda-diagram" for N =Z nuclei in 1968 [9], which has been recently modified and extended by von Oertzen [10] for neutron-rich nuclei, as shown in the left panel of Fig.2.…”