Strong correlation of the neutron star core-crust transition density with the a-meson mass via vacuum polarization

We study the neutron star core-crust transition density pt with the inclusion of the vacuum polarization in the dielectric function in the nonlinear relativistic Hartree approach (RHAn). It is found that the strong correlation between the pt and the scalar meson mass ma strikingly overwhelms the uncertainty of the nuclear equation of state in the RHAn models, in contrast to the usual awareness that pt is predominantly sensitive to the isovector nuclear potential and symmetry energy. The accurate extraction of pt through the future gravitational wave measurements can thus provide a strong constraint on the longstanding uncertainty of ma, which is of significance to better infer the vacuum property. As an astrophysical implication, it suggests that the correlation between pt and ma is very favorable to reconcile the difficulty in reproducing the large crustal moment of inertia for the pulsar glitches with the well constrained symmetry energy.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/). Funded by SCOAP3.

Automated summary

We investigate the neutron star core-crust transition density pt by considering the vacuum polarization in the dielectric function within the nonlinear relativistic Hartree approach (RHAn). It is discovered that the strong correlation between pt and the scalar meson mass ma exceeds the uncertainty in the nuclear equation of state in the RHAn models, contrary to the common belief that pt is mainly sensitive to the isovector nuclear potential and symmetry energy. Accurately determining pt through future gravitational wave measurements can impose a strong constraint on the long-standing uncertainty of ma and improve our understanding of vacuum properties. As an astrophysical implication, the correlation between pt and ma helps reconcile the difficulty in reproducing the large crustal moment of inertia for pulsar glitches with the well-constrained symmetry energy.