The effect of the proton excess parameter on the properties of neutron star

The equation of state of neutron matter is investigated using a velocity dependent two-body interaction. We introduce a parameter which measures the excess of protons in the neutron matter (D). The parameter D enabled us to study pure neutron matter and symmetric nuclear matter properties. The energy, pressure and compression modulus of nuclear matter are investigated through their dependence on the proton excess parameter D. It is found that nuclear matter exists in a stable one phase for D ≥ 0.4. For D ≤ 0.5, the nuclear matter exhibits a liquid-gas phase transition. Similar investigations of the mass and radius of neutron star on D is done. The maximum mass of the star is found to increase with D and the radius decreases. The temperature is found to have a small effect on the neutron star properties. (author). 28 refs, 7 figs, 3 tabs