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

Abstract

We study the neutron star core-crust transition density ρt 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 ρt and the scalar meson mass mσ strikingly overwhelms the uncertainty of the nuclear equation of state in the RHAn models, in contrast to the usual awareness that ρt is predominantly sensitive to the isovector nuclear potential and symmetry energy. The accurate extraction of ρt through the future gravitational wave measurements can thus provide a strong constraint on the longstanding uncertainty of mσ, which is of significance to better infer the vacuum property. As an astrophysical implication, it suggests that the correlation between ρt and mσ 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.

Keywords

• σ meson mass
• Neutron star crust-core transition density
• Relativistic Hartree approximation
• Relativistic random phase approximation