Implications of parity-violating electron scattering experiments on $^{48}$Ca (CREX) and $^{208}$Pb (PREX-II) for nuclear energy density functionals

TL;DR

This paper examines how recent parity-violating electron scattering experiments on calcium-48 and lead-208 influence nuclear energy density functionals, revealing inconsistencies and the need for further research in modeling neutron skin properties.

Contribution

It analyzes the impact of CREX and PREX-II data on EDF parameters, highlighting discrepancies in constraining isovector properties of nuclei.

Findings

CREX data leads to smaller symmetry energy parameters.

PREX-II data results in larger neutron skin thickness.

CREX and PREX-II data are inconsistent in constraining EDFs.

Abstract

Recent precise parity-violating electron scattering experiments on $^{48}$Ca (CREX) and $^{208}$Pb (PREX-II) provide a new insight on the formation of neutron skin in nuclei. Within the energy density functional (EDF) framework, we investigate the implications of CREX and PREX-II data on nuclear matter symmetry energy and isovector properties of finite nuclei: neutron skin thickness and dipole polarizability. The weak-charge form factors from the CREX and PREX-II experiments are employed directly in constraining the relativistic density-dependent point coupling EDFs. The EDF established with the CREX data acquires considerably smaller values of the symmetry energy parameters, neutron skin thickness and dipole polarizability both for $^{48}$Ca and $^{208}$Pb, in comparison to the EDF obtained using the PREX-II data, and previously established EDFs. Presented analysis shows that CREX and PREX-II experiments could not provide consistent constraints for the isovector sector of the EDFs, and further theoretical and experimental studies are required.