Constraining the nuclear symmetry energy with electric dipole polarizability and neutron skin characteristics in \texorpdfstring{$^{208}\mathrm{Pb}$}{208Pb} within antisymmetrized molecular dynamics

Abstract

The electric dipole polarizability $\alpha_D$ and the neutron-skin thickness $\Delta R_{np}$ of $^{208}\mathrm{Pb}$ are two powerful and clean probes for constraining the symmetry energy at subsaturation densities. Within the framework of the antisymmetrized molecular dynamics (AMD) model, the width of the strength function and its dynamical origins are understood, and the $\alpha_D$ and $\Delta R_{np}$ data favor effective interaction parameter sets with $S_0\approx32$-34 MeV and $L=64$-87 MeV. In addition, our calculations show that the sensitive densities of $\alpha_D$ and $\Delta R_{np}$ range from 0.2$\rho_0$ to 0.57$\rho_0$, and the corresponding values of the symmetry energy at the lower and upper ends of this sensitive density region are $S(0.2\rho_0)=10.18\pm 1.10$ MeV and $S(0.57\rho_0)=22.31\pm 1.32$ MeV.