Constraining the slope parameter of the symmetry energy from nuclear structure

Four quantities deducible from nuclear structure experiments have been claimed to correlate with the slope parameter L of the symmetry energy: neutron skin thickness, cross section of low-energy dipole (LED) mode, dipole polarizability alpha(D), and alpha S-D(0) (i. e., product of alpha(D) and symmetry energy S-0). By means of calculations in the Hartree-Fock plus random-phase approximation with various effective interactions, we compare the correlations between L and these four quantities. The correlation derived from different interactions and the correlation from a class of interactions that are identical in symmetric matter as well as in S-0 are simultaneously examined. These two types of correlation may behave differently, as exemplified in the correlation of aD to L. It is found that the neutron skin thickness and alpha S-D(0) correlate well to L, and therefore are suitable for narrowing down the value of L via experiments. The LED emergence and upgrowth makes the alpha S-D(0)-L correlation strong, although these correlations are disarranged when a neutron halo appears in the ground state.