Clusters in light nuclei: history and recent developments

Abstract

In this review, we discuss recent advancements in the study of clustering phenomena occurring in light nuclei, and their influence on nuclear structure, dynamics, and astrophysics. In the introduction, we outline the historical steps leading to the concept of $$\alpha $$ α -clusterization in nuclei and provide a comprehensive description of the evolution of nuclear models capable to describe clustering aspects in nuclear systems and of the main experiments and discoveries leading to the development of this research field. We also describe some spectroscopic techniques that are used to establish the clustered nature of a given nuclear state. Some relevant experimental and theoretical findings recently reported both in experimental and theoretical works are discussed in the text. We put emphasis on recent achievements and remaining problems in the description of the structure of light isotopes, from helium to neon, including both self- and non-self-conjugate nuclei. Particular attention to the implication in the nuclear astrophysics context and to clustering effects in the dynamics of nuclear reactions is pursued all along the review.

Symmetries in Collisions as Explored through the Harmonic Oscillator

“…These symmetries relate to the spin and orbital angular momentum of the nucleus and the approximate isospin symmetry, which involves neutrons and protons. However, there are other symmetries that involve how nucleons organize themselves inside nuclei, associated with the phenomenon of nuclear clustering [3][4][5].…”

“…In order, the terms correspond to a volume energy (a V A), associated with the interactions felt by the A nucleons and accounting for the saturation of the nuclear force (i.e., nucleons only interact with those in close proximity). From this, correction terms associated with the deficit of nucleons at the surface (a S A 2 3 , nucleons at the surface have ~50% fewer nucleons to interact with), the Coulomb repulsion of protons (a C Z(Z − 1)/A 1 3 ), and the imbalance of protons and neutrons (a A (N − Z) 2 /A) are subtracted, and then finally, a pairing term δ(N, Z) is added.…”