CREX and PREX-II reconciled within nuclear energy density functional theory
Phys. Rev. C 114, 034331 – Published 25 September, 2026
DOI: https://doi.org/10.1103/2rt9-cknc
Abstract
The CREX and PREX-II measurements of the neutron-skin thickness of and challenge standard nuclear energy-density functional (EDF) descriptions of nuclei and nuclear matter. It is shown that the apparent tension arises from an implicit constraint in current EDF parametrizations that ties the density dependence of the functional at the dilute nuclear surface to that of uniform matter near saturation. Relaxing this surface-bulk coupling and independently constraining the dilute-density sector, while preserving realistic saturation properties and the high-density equation of state, yields EDFs that simultaneously reproduce the neutron skins of both nuclei, their electric dipole polarizabilities, and neutron-star mass-radius relations. The established correlation between the neutron-skin thickness and the symmetry-energy slope parameter at saturation is retained but becomes substantially broader. The results show that current neutron-skin data do not require extreme values of and highlight an underconstrained degree of freedom associated with low-density nuclear matter.