The equation of state of nuclear matter and the neutron star structure

We examine a relationship between the phenomenological equation of state of nuclear matter near normal nuclear density and the structure of neutron stars. We find that the neutron star mass at fixed central density is an increasing function of the symmetry energy density derivative coefficient L, and that L must be large enough to support a neutron star having the observed canonical mass (1.4 solar mass). This feature could provide a constraint on the L value, which would complement a possible constraint to be obtained from systematic measurements of radii of neutron-rich nuclei. We expect, on the other hand, that the L value, once determined experimentally, would enable us to describe more precisely the structure of neutron stars having low central densities (2-3 times the nuclear density). (author)