Triton/${}^3$He ratio as an observable for neutron skin thickness

Abstract

Based on the framework of the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model in which the initial neutron and proton densities are sampled according to the droplet model, the correlation between triton-to-${}^3$He yield ratio (R(t/${}^3$He)$=$Yield(t)/Yield(${}^3$He)) and neutron skin thickness ($\hat{I}{´}_{np}$) in neutron-rich projectile induced reactions is investigated. By changing the diffuseness parameter of neutron density distribution in the droplet model for the projectile to obtain different $\hat{I}{´}_{np}$, the relationship between $\hat{I}{´}_{np}$ and the corresponding R(t/${}^3$He) in semi-peripheral collisions is obtained. The calculated results show that R(t/${}^3$He) has a strong linear correlation with $\hat{I}{´}_{np}$ for neutron-rich ${}^{50}$Ca and ${}^{68}$Ni nuclei. It is suggested that R(t/${}^3$He) could be regarded as a good experimental observable to extract $\hat{I}{´}_{np}$ for neutron-rich nuclei because the yields of charged particles triton and ${}^3$He can be measured quite precisely.

7 pages and 6 figures