Information Content of the Parity-Violating Asymmetry in ²º⁸Pb [Information Content of the Parity-Violating Asymmetry in P-208]

The parity-violating asymmetry A(PV) in Pb-208, recently measured by the PREX-2 Collaboration, is studied using modem relativistic (covariant) and nonrelativistic energy density functionals. We first assess the theoretical uncertainty on A(PV) which is intrinsic to the adopted approach. To this end, we use quantified functionals that are able to accommodate our previous knowledge on nuclear observables such as binding energies, charge radii, and the dipole polarizability alpha(D) of Pb-208. We then add the quantified value of A(PV) together with alpha(D) to our calibration dataset to optimize new functionals. Based on these results, we predict a neutron skin thickness in Pb-208 r(skin) = 0.19 +/- 0.02 fm and the symmetry-energy slope L = 54 +/- 8 MeV. These values are consistent with other estimates based on astrophysical data and are significantly lower than those recently reported using a particular set of relativistic energy density functionals. We also make a prediction for the A(PV) value in Ca-48 that will be soon available from the CREX measurement.