One- and two-nucleon transfer in $^{\mathbf{116}}$Sn+$^{\mathbf{60}}$Ni: A coupled reaction channel analysis

TL;DR

This study employs microscopic coupled reaction channel calculations with realistic potentials and shell-model inputs to analyze one- and two-nucleon transfer processes in the $^{116}$Sn+$^{60}$Ni system, achieving excellent agreement with experimental data.

Contribution

It demonstrates the feasibility of a fully microscopic CRC approach for heavy-ion nucleon transfer without arbitrary normalization, incorporating detailed nuclear structure and reaction mechanisms.

Findings

Excellent agreement with experimental quasielastic scattering and one-neutron transfer data.

Best description of one-proton transfer achieved using experimental spectroscopic amplitudes.

Extreme cluster mechanism best reproduces two-nucleon transfer data.

Abstract

Recent studies of multi-nucleon transfer in heavy ion collisions have employed both macroscopic and microscopic models. Although macroscopic approaches offer useful insights, microscopic analyses of high-precision experimental data provide a more reliable framework for understanding the nucleon transfer mechanisms. The present study aims to carry out a comprehensive theoretical investigation of the $^{116}$Sn+$^{60}$Ni system using microscopic coupled reaction channel (CRC) calculations. The calculations employ microscopic double-folding S$\tilde{a}$o Paulo potentials, incorporating all relevant inelastic and transfer couplings guided by observed $\gamma$-ray transitions, wherever available. For the one-nucleon transfer channels, spectroscopic amplitudes are also obtained from large-scale shell-model calculations. In the case of two-nucleon transfer, sequential, microscopic cluster and extreme cluster mechanisms are considered to reproduce the data. Results for quasielastic scattering and one-neutron ($1n$) transfer show excellent agreement with experimental data. Measured one-proton ($1p$) transfer probabilities are best described by incorporating experimental spectroscopic amplitudes in the CRC calculations. For transfer of two-nucleons, the extreme cluster mechanism is found to best reproduce the data. This study highlights that microscopic description of one- and two-nucleon transfer between two heavy ions in the CRC framework, without taking recourse to arbitrary normalization of the cross sections, is quite feasible. Nonetheless, lack of experimental corroboration for all the transitions included in the calculations and practical limits of computational resources, affecting accuracy of shell-model results and causing a cap on the number of states, leave room for further refinement of the results.