%0 Journal Article
%T The neutron skin thickness from the measured electric dipole polarizability in $^{68}$Ni, $^{120}$Sn, and $^{208}$Pb
%A X. Roca-Maza
%A X. Vi£żas
%A M. Centelles
%A B. K. Agrawal
%A G. Colo'
%A N. Paar
%A J. Piekarewicz
%A D. Vretenar
%J Physics
%D 2015
%I arXiv
%R 10.1103/PhysRevC.92.064304
%X The information on the symmetry energy and its density dependence is deduced by comparing the available data on the electric dipole polarizability $\alpha_D$ of ${}^{68}$Ni, ${}^{120}$Sn, and ${}^{208}$Pb with the predictions of the Random Phase Approximation, using a representative set of nuclear energy density functionals. The calculated values of $\alpha_D$ are used to validate different correlations involving $\alpha_D$, the symmetry energy at the saturation density $J$, the corresponding slope parameter $L$ and the neutron skin thickness $\Delta r_{\!np}$, as suggested by the Droplet Model. A subset of models that reproduce simultaneously the measured polarizabilities in ${}^{68}$Ni, ${}^{120}$Sn, and ${}^{208}$Pb are employed to predict the values of the symmetry energy parameters at saturation density and $\Delta r_{\!np}$. The resulting intervals are: $J\!=\!30 \text{-}35$ MeV, $L\!=\!20 \text{-} 66$ MeV; and the values for $\Delta r_{\!np}$ in ${}^{68}$Ni, ${}^{120}$Sn, and ${}^{208}$Pb are in the ranges: 0.15\text{-}0.19 fm, 0.12\text{-}0.16 fm, and 0.13\text{-}0.19 fm, respectively. The strong correlation between the electric dipole polarizabilities of two nuclei is instrumental to predict the values of electric dipole polarizabilities in other nuclei.
%U http://arxiv.org/abs/1510.01874v2