Nuclear clusters and nuclear molecules
TL;DR: In this article, the first examples of hyper-deformed structures in nuclei with an axis ratio of 3:1 were presented, in the case of the beryllium isotopes.
About: This article is published in Physics Reports.The article was published on 2006-09-01. It has received 345 citations till now. The article focuses on the topics: Isotopes of beryllium & Neutron.
Citations
More filters
TL;DR: The theoretical status of coexistence in nuclei is summarized in this article, where microscopic shell-model descriptions and mean-field descriptions are emphasized, and a systematic data for both even and odd-mass nuclei, selected to illustrate the various ways in which coexistence is observed in nucleis.
Abstract: Shape coexistence in nuclei appears to be unique in the realm of finite many-body quantum systems It differs from the various geometrical arrangements that sometimes occur in a molecule in that in a molecule the various arrangements are of the widely separated atomic nuclei In nuclei the various ''arrangements'' of nucleons involve (sets of) energy eigenstates with different electric quadrupole properties such as moments and transition rates, and different distributions of proton pairs and neutron pairs with respect to their Fermi energies Sometimes two such structures will ''invert'' as a function of the nucleon number, resulting in a sudden and dramatic change in ground-state properties in neighboring isotopes and isotones In the first part of this review the theoretical status of coexistence in nuclei is summarized Two approaches, namely, microscopic shell-model descriptions and mean-field descriptions, are emphasized The second part of this review presents systematic data, for both even- and odd-mass nuclei, selected to illustrate the various ways in which coexistence is observed in nuclei The last part of this review looks to future developments and the issue of the universality of coexistence in nuclei Surprises continue to be discovered With the major advances in reaching to extremes of proton-neutronmore » number, and the anticipated new ''rare isotope beam'' facilities, guidelines for search and discovery are discussed« less
570 citations
TL;DR: In this paper, the structural evolution along the isotonic and isotopic chains around the “traditional” magic numbers 8, 20, 28, 50, 82 and 126 is discussed using complementary experimental information, such as the binding energies of the orbits bounding the shell gaps.
466 citations
TL;DR: In this paper, a review of the development of clustering in light nuclei is presented, mostly from the stand-point of the harmonic oscillator framework, which allows a unifying description of alpha-conjugate and neutron-rich 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 3?-cluster state in 12C, nuclear molecules and clustering at the drip-line Finally, an understanding of the 12C+12C resonances in 24Mg, within the framework of the theoretical ideas developed in the review, is presented
247 citations
TL;DR: In most nuclei, protons and neutrons are smoothly distributed throughout the nuclear volume. Exceptions to this rule are molecularlike states, especially in light nuclei where light nuclear clusters such as alpha particles are present as discussed by the authors.
Abstract: In most nuclei, protons and neutrons are smoothly distributed throughout the nuclear volume. Exceptions to this rule are molecularlike states, especially in light nuclei, where light nuclear clusters such as alpha particles are present. The most prominent example is the 7.65 MeV Hoyle state in carbon-12 that plays an essential role in the production of carbon in stars in the triple-alpha process. This work reviews progress and prospects in the studies of nuclear clustering, including molecular states in alpha-conjugate and neutron-rich systems.
196 citations
Cites background from "Nuclear clusters and nuclear molecu..."
...In essence, it is possible to form linear combinations of the neutron wave function around the α-particle cores and obtain, for example, twocentered molecules with delocalized neutrons in π and σorbitals (Freer, 2007; von Oertzen et al., 2006)....
[...]
...There are many review articles which describe the development of the subject and we refer the reader to the following references: (Beck, 2010, 2012, 2014; Freer and Fynbo, 2014; Freer and Merchant, 1997; Freer, 2007; von Oertzen et al., 2006)....
[...]
...There have been a number of reviews on clustering in nuclei (Akaishi et al., 1986; Beck, 2010, 2012, 2014; Freer, 2007; Funaki et al., 2015; Horiuchi et al., 2012; von Oertzen et al., 2006)....
[...]
...To understand cluster structures of low-lying states of neutron-rich Be isotopes, molecular orbitals (MO) for surrounding neutrons around the 2α core were proposed (Itagaki and Okabe, 2000; Ito and Ikeda, 2014; von Oertzen, 1996b; von Oertzen et al., 2006; Seya et al., 1981a)....
[...]
...It is also possible to build more complex molecular structures with non-identical cores, for example, in nuclei such as 21,22Ne (von Oertzen et al., 2006)....
[...]
TL;DR: In this article, a large-scale axial relativistic Hartree-Bogoliubov calculations are performed for all even-even nuclei between the two-proton and two-neutron drip lines with four modern covariant energy density functionals such as NL3*, DD-ME2, DD- ME$\ensuremath{\delta}$, and DD-PC1.
Abstract: Covariant density functional theory is a modern theoretical tool for the description of nuclear structure phenomena. The current investigation aims at the global assessment of the accuracy of the description of the ground state properties of even-even nuclei. We also estimate theoretical uncertainties defined here as the spreads of predictions within four covariant energy density functionals in known regions of the nuclear chart and their propagation towards the neutron drip line. Large-scale axial relativistic Hartree-Bogoliubov calculations are performed for all $Z\ensuremath{\le}104$ even-even nuclei between the two-proton and two-neutron drip lines with four modern covariant energy density functionals such as NL3*, DD-ME2, DD-ME$\ensuremath{\delta}$, and DD-PC1. The physical observables of interest include the binding energies, two-particle separation energies, charge quadrupole deformations, isovector deformations, charge radii, neutron skin thicknesses, and the positions of the two-proton and two-neutron drip lines. The predictions for the two-neutron drip line are also compared in a systematic way with the ones obtained in nonrelativistic models.
162 citations
References
More filters
TL;DR: In this paper, the authors reviewed various results related to the single-particle structure in spherical and deformed nuclei, discussed from the viewpoint of the so-called shell-correction method.
Abstract: This paper reviews various results related to the single-particle structure in spherical and deformed nuclei, discussed from the viewpoint of the so-called shell-correction method. This method stresses the importance of large-scale nonuniformities in the energy distribution of the individual particles especially near the Fermi energy. The way in which these nonuniformities affect in an essential way many nuclear properties, such as the shape stiffness, the spatial density distribution, the total mass of the nucleus, the mass and inertia of the nuclear shape variations, etc. is also discussed. Against this background, the behavior of the nuclear deformation energy is described, in particular for larger distortions relevant to the fission process. In this connection, some qualitative singularities of the phenomenological liquid-drop deformation energy at large shape distortions are pointed out, and their possible implications for fission are discussed. As the problems considered cover a wide range of nuclear properties, this paper is not a review in the narrow sense of the word. Comparison with other approaches as well as historic references are given mainly to clarify specific points, because a complete review would be a monumental undertaking.
1,250 citations
Book•
01 Jun 1977
TL;DR: In this article, the Schröter equation is formulated as a projection equation and basis wave functions can be chosen in such a way that the incoming and reaction channels are contained in a completely symmetric way in related coupled-channel equations.
Abstract: The different phenomena which play a role in low energy nuclear physics, such as reactions and bound state properties of the nuclei, are considered from a unified microscopic point of view. To achieve this the microscopic, many- particle Schroedinger equation is formulated as a projection equation. Consequently basis wave functions can be introduced which describe the nuclear system under consideration in a very flexible way, adjusted to the experimental conditions. This means for instance that the basis wave functions can be chosen in such a way that the incoming and reaction channels are contained in a completely symmetric way in the related coupled-channel equations. The specific experimental situation which one wants to describe is then taken into account by the boundary conditions of the solutions of the coupled-channel equations. One central point of this theory is the influence of the Pauli principle which resolves for instance the seemingly contradictory features of many nuclear phenomena such as e.g., single particle features and collective features. 3 figures. (auth)
703 citations
TL;DR: A review of the evidence on the properties of the nuclei A = 8, 9 and 10, with emphasis on material leading to information about the structure of the A =8, 9, 10 systems is given in this paper.
643 citations