Breakup reaction models for two- and three-cluster projectiles

TL;DR

This paper reviews various theoretical models for nuclear breakup reactions involving two- and three-cluster projectiles, emphasizing their applications to exotic nuclei and astrophysics, and discusses recent extensions and future directions.

Contribution

It provides a comprehensive comparison of reaction models including semiclassical, eikonal, and CDCC approaches, highlighting recent advances for three-cluster projectiles.

Findings

Models successfully describe breakup of two-cluster projectiles.

Extensions to three-cluster projectiles like two-neutron halo nuclei are discussed.

Future perspectives on breakup-reaction theory are presented.

Abstract

Breakup reactions are one of the main tools for the study of exotic nuclei, and in particular of their continuum. In order to get valuable information from measurements, a precise reaction model coupled to a fair description of the projectile is needed. We assume that the projectile initially possesses a cluster structure, which is revealed by the dissociation process. This structure is described by a few-body Hamiltonian involving effective forces between the clusters. Within this assumption, we review various reaction models. In semiclassical models, the projectile-target relative motion is described by a classical trajectory and the reaction properties are deduced by solving a time-dependent Schroedinger equation. We then describe the principle and variants of the eikonal approximation: the dynamical eikonal approximation, the standard eikonal approximation, and a corrected version avoiding Coulomb divergence. Finally, we present the continuum-discretized coupled-channel method (CDCC), in which the Schroedinger equation is solved with the projectile continuum approximated by square-integrable states. These models are first illustrated by applications to two-cluster projectiles for studies of nuclei far from stability and of reactions useful in astrophysics. Recent extensions to three-cluster projectiles, like two-neutron halo nuclei, are then presented and discussed. We end this review with some views of the future in breakup-reaction theory.