Information Content of the Parity-Violating Asymmetry in 208Pb
Abstract
The parity-violating asymmetry APV in 208Pb, recently measured by the PREX-2 Collaboration, is studied using modern relativistic (covariant) and nonrelativistic energy density functionals. We first assess the theoretical uncertainty on APV 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 αD of 208Pb. We then add the quantified value of APV together with αD to our calibration dataset to optimize new functionals. Based on these results, we predict a neutron skin thickness in 208Pb rskin=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 APV value in 48Ca that will be soon available from the CREX measurement.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2021
- DOI:
- 10.1103/PhysRevLett.127.232501
- arXiv:
- arXiv:2105.15050
- Bibcode:
- 2021PhRvL.127w2501R
- Keywords:
-
- Nuclear Theory
- E-Print:
- 11 pages, 6 figures