Neutron-transfer induced breakup of the Borromean nucleus $^9$Be

TL;DR

This paper investigates neutron-transfer induced breakup of the Borromean nucleus $^9$Be using a complex potential model and a three-body approach, successfully matching experimental data across various energies.

Contribution

It introduces a combined theoretical framework employing the Ichimura-Austern-Vicent model and a three-body $^9$Be model to accurately predict breakup cross sections.

Findings

Calculated cross sections agree with experimental data

Energy spread of single-particle strength is significant

Effective modeling of $^{198}$Au states improves accuracy

Abstract

We address the problem of evaluating neutron-transfer induced breakup cross sections caused by the Borromean nucleus $^{9}$Be, using the reaction $^{197}$Au($^{9}$Be,$^{8}$Be)$^{198}$Au as a test case. This reaction was recently measured over a wide range of incident energies around the Coulomb barrier. To deal with the high density of $^{198}$Au states that can be potentially populated in this reaction, we employ the Ichimura, Austern, Vicent model, in which the spectrum of physical states for this system is replaced by the solutions of a complex n+$^{197}$Au potential, accounting effectively for the fragmentation of single-particle states into physical states. Furthermore, to account for the unbound nature of the emitted $^{8}$Be system, we employ a three-body model of $^{9}$Be. The calculated stripping cross sections are found to be in good agreement with existing data over a wide range of incident energies. The importance of taking into account the energy spread of the single-particle strength of the outgoing $^{8}$Be and the target-like residual nucleus is discussed.