Examination of the influence of the f${}_0$(975) and $\varphi$(1020) mesons on the surface gravitional redshift of the neutron star PSR J0348+0432

Abstract

The effect of the mesons $f_0(975)$ and $\varphi (1020)$ on the surface gravitional redshift of the neutron star PSR J0348+0432 is examined in the framework of the relativistic mean field theory by choosing the suitable hyperon coupling constants. We find that compared with that without considering the mesons $f_0(975)$ and $\varphi (1020)$, the value range of the radius $R$ of the neutron star PSR J0348+0432 would be changed from a narrow range 12.964 km $\sim$ 12.364 km to a wider range 12.941 km $\sim$ 11.907 km corresponding to the observation mass M=1.97 M${}_{\odot }$$\sim$2.05 M${}_{\odot }$. We also find that the value range of the surface gravitational redshift $z$ of the neutron star PSR J0348+0432 changes from 0.3469 $\sim$ 0.3997 to 0.3480 $\sim$ 0.4263 corresponding to the observation mass M=1.97 M${}_{\odot }$$\sim$2.05 M${}_{\odot }$ as the mesons $f_0(975)$ and $\varphi (1020)$ being considered. These mean the radius $R$ and the surface gravitational redshift $z$ all will be constrained in a wider scope as the mesons $f_0(975)$ and $\varphi (1020)$ being considered. We also can see that the difference of the radius and the surface gravitational redshift is not so large whether the mesons $f_0(975)$ and $\varphi (1020)$ being considered or not. This indicates that the mesons $f_0(975)$ and $\varphi (1020)$ do not play a major role in the massive neutron star PSR J0348+0432.

Comments: 5 pages,3 figures, This paper was published in Physical Review C, 2015, 92(5): 055802