Neutron star core-crust transition and the crustal moment of inertia in the nonlinear relativistic Hartree approximation*

Abstract

We investigate the effects of the $\sigma$ meson mass ($m_\sigma$), symmetry energy and its slope on the neutron star core-crust transition density and the crustal moment of inertia ($\Delta I/I$) in the nonlinear relativistic Hartree approach (RHA), which includes vacuum polarization. Although the core-crust transition density ($\rho_{t}$), pressure ($P_{t}$), and neutron star radius ($R$) that are all dependent on the symmetry energy all contribute to determining $\Delta I/I$, we find that changing only the slope of symmetry energy within a reasonable range is not sufficient to reach $\Delta I/I\geq7\%$ to achieve the large glitches of the Vela pulsar. However, since all three factors ($\rho_{t}$, $P_{t}$, and $R$) increase with the increase of $m_\sigma$ through scalar vacuum polarization, adjusting $m_\sigma$ can easily achieve $\Delta I/I\geq7\%$.