Coupled-channels description of multinucleon transfer and fusion reactions at energies near and far below the Coulomb barrier

TL;DR

This paper develops a coupled-channels framework to analyze multinucleon transfer and fusion reactions near and below the Coulomb barrier, improving agreement with experimental data and highlighting the importance of collective state couplings.

Contribution

It introduces a comprehensive coupled-channels model that incorporates high-order effects and collective excitations to accurately describe transfer and fusion reactions.

Findings

Direct coupling improves transfer cross section fits.

High order terms significantly affect transfer probabilities.

Couplings to collective states influence transfer near the Coulomb barrier.

Abstract

We investigate heavy-ion multinucleon transfer reactions using the coupled-channels formalism. We first use the semi-classical approximation and show that a direct coupling between the entrance and the pair transfer channels improves a fit to the experimental one- and two-neutron transfer cross sections for the 40Ca+96Zr and 60Ni+116Sn systems. We then discuss the validity of the perturbative approach and highlight the effect of high order terms. The effect of absorption is also investigated for energies around the Coulomb barrier. Finally, we use a quantal coupled-channels approach to achieve a simultaneous description of the fusion cross sections and the transfer probabilities for the 40Ca+96Zr reaction. We find a significant effect of the couplings to the collective excited states on the transfer probabilities around the Coulomb barrier.