Neutron/proton ratio of nucleon emissions as a probe of neutron skin

TL;DR

This study explores how the neutron-to-proton emission ratio ($R_{np}$) correlates with neutron skin thickness ($ abla_{np}$) in neutron-rich nuclei, proposing $R_{np}$ as an experimental probe for nuclear structure and EOS insights.

Contribution

It introduces a method to relate $R_{np}$ to $ abla_{np}$ using the IQMD model with Droplet model densities, enabling extraction of neutron skin thickness from experimental data.

Findings

Strong linear correlation between $R_{np}$ and $ abla_{np}$ for Ca and Ni isotopes.

$R_{np}$ can serve as an observable to determine neutron skin thickness.

Potential to improve understanding of exotic nuclei and nuclear matter EOS.

Abstract

The dependence between neutron-to-proton yield ratio ($R_{np}$) and neutron skin thickness ($\delta_{np}$) in neutron-rich projectile induced reactions is investigated within the framework of the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model. The density distribution of the Droplet model is embedded in the initialization of the neutron and proton densities in the present IQMD model. By adjusting the diffuseness parameter of neutron density in the Droplet model for the projectile, the relationship between the neutron skin thickness and the corresponding $R_{np}$ in the collisions is obtained. The results show strong linear correlation between $R_{np}$ and $\delta_{np}$ for neutron-rich Ca and Ni isotopes. It is suggested that $R_{np}$ may be used as an experimental observable to extract $\delta_{np}$ for neutron-rich nuclei, which is very significant to the study of the nuclear structure of exotic nuclei and the equation of state (EOS) of asymmetric nuclear matter.