Effect of channel coupling on the elastic scattering of lithium isotopes

TL;DR

This study investigates how channel coupling influences the elastic scattering of lithium isotopes on carbon and silicon targets at intermediate energies, revealing the stabilizing role of valence neutrons and their glue-like behavior.

Contribution

It introduces a microscopic coupled-channel approach with wave functions from the SMCM method to analyze lithium isotope scattering, highlighting the impact of valence neutrons.

Findings

Valence neutrons exhibit glue-like behavior attracting clusters.

Channel coupling effects significantly influence elastic scattering cross sections.

Valence neutrons stabilize core bindings and reduce core excitation effects.

Abstract

Herein, we investigated the channel coupling (CC) effect on the elastic scatterings of lithium (Li) isotopes ($A =$ 6--9) for the $^{12}$C and $^{28}$Si targets at $E/A =$ 50--60 MeV. The wave functions of the Li isotopes were obtained using the stochastic multi-configuration mixing (SMCM) method based on the microscopic-cluster model. The proton radii of the $^{7}$Li, $^{8}$Li, and $^{9}$Li nuclei became smaller as the number of valence neutrons increased. The valence neutrons in the $^{8}$Li and $^{9}$Li nuclei exhibited a glue-like behavior, thereby attracting the $\alpha$ and $t$ clusters. Based on the transition densities derived from these microscopic wave functions, the elastic-scattering cross section was calculated using a microscopic coupled-channel (MCC) method with a complex $G$-matrix interaction. The existing experimental data for the elastic scatterings of the Li isotopes and $^{10}$Be nuclei were well reproduced. The Li isotope elastic cross sections were demonstrated for the $^{12}$C and $^{28}$Si targets at $E/A$ =53 MeV. The glue-like effect of the valence neutrons on the Li isotope was clearly demonstrated by the CC effect on elastic scattering. Finally, we realize that the valence neutrons stabilized the bindings of the core parts and the CC effect related to core excitation was indeed reduced.