Neutron skin thickness in $^{\textbf{208

Abstract

Accurate knowledge about the neutron skin thickness $\Delta R_{\rm{np}}$ in $^{208}$Pb has far-reaching influence on different communities of nuclear physics and astrophysics. The novel Lead Radius Experiment (PREX), however, did not yield stringent constraint on the $\Delta R_{\rm{np}}$ recently. We summed our recent works that in particular we employ a more practicable strategy currently to probe the neutron skin thickness of $^{208}$Pb based on a high linear correlation between the $\Delta R_{\rm{np}}$ and $J-a_{\rm{sym}}$, where $J$ and $a_{\rm{sym}}$ are the symmetry energy (coefficient) of nuclear matter at saturation density and of $^{208}$Pb. Compared with the parity-violating asymmetry $A_{\rm{PV}}$ in the PREX, the reliably experimental information on the $J-a_{\rm{sym}}$ is much more easily available attributed to a wealth of measured nuclear masses and on decay energies. In addition, the density dependence of the symmetry energy is also well constrained with the $J-a_{\rm{sym}}$. Finally, based on a `tomoscan method, we proposed that one just needs to measure the nucleon densities in $^{208}$Pb starting from $R_\rm{m} = (7.61\pm0.04)$ fm to obtain the $\Delta R_{\rm{np}}$ in hadron scattering experiments, regardless of its interior profile.