Implications of PREX-2 on the electric dipole polarizability of neutron-rich nuclei

The recent announcement by the PREX collaboration of an unanticipated thick neutron skin in 208Pb (Rskin208) has challenged our understanding rich matter vicinity nuclear saturation density. Whereas earlier constraints indicate that symmetry energy is relatively soft, PREX-2 result seems to suggest opposite. We confront on obtained from measurements electric dipole polarizability against those informed measurement Rskin208 and correlations it entails. Covariant density functionals properties finite nuclei are used compute response 48Ca, 68Ni, 132Sn, 208Pb. set this work consistent with experimental data, yet flexible enough they span a wide range values Rskin208. It found theoretical predictions systematically overestimate corresponding extracted direct distribution strength. thickness parity violating electron scattering measured photoabsorption experiments two cleanest tools constrain around However, value suggests fairly stiff stands stark contrast conclusions derived polarizability. At present, we offer no solution dilemma.