Phenomenological nucleon-nucleon potentials and the equation of state of neutron star matter

We have calculated the equation of state of the neutron star matter and some of its properties for a wide range of nucleon-nucleon potentials using the lowest order constrained variational (LOCV) method. It turns out that for the UV14 + TNI potential, the proton fraction exhibits a peak and falls off at high densities. The equation of state with the UV14 + TNI potential is seen to be much harder than those with other potentials. The polytropic behaviour of the neutron star matter with various potentials are discussed. Compared with the other methods, the LOCV results show good agreement for densities below 0.7f m(-3). Above this density, however, the differences with other methods are appreciable.