Effect of the $\sigma$-cut potential on the properties of neutron stars with or without a hyperonic core

TL;DR

This study investigates how the $\sigma$-cut potential influences the equation of state and properties of neutron stars, including those with hyperonic cores, aligning theoretical models with recent high-mass pulsar observations and gravitational wave data.

Contribution

It introduces the application of the $\sigma$-cut potential within the RMF model to produce stiffer EOSs, enabling neutron star mass predictions consistent with recent observations, especially for hyperonic cores.

Findings

$\sigma$-cut potential increases neutron star mass by about 10%.

Results agree with GW170817 and other observational constraints.

EOS becomes stiffer at high densities, supporting high-mass neutron stars.

Abstract

Motivated by the recent observation of high-mass pulsars ($M \simeq 2 M_{\odot}$), we employ the $\sigma$-cut potential on the equation of state (EOS) of high-density matter and the properties of neutron stars within the relativistic mean-field (RMF) model using TM1$^{*}$ parameter set. The $\sigma$-cut potential is known to reduce the contributions of the $\sigma$ field, resulting in a stiffer EOS at high densities and hence leading to larger neutron star masses without affecting the properties of nuclear matter at normal saturation density. We also analyzed the effect of the same on pure neutron matter and also on the neutron star matter with and without hyperonic core and compared it with the available theoretical, experimental, and observational data. The corresponding tidal deformability ($\Lambda_{1.4}$) is also calculated. With the choice of meson-hyperon coupling fixed to hypernuclear potentials, we obtain $\approx 10~\%$ increase in mass by employing the $\sigma$-cut potential for $f_{s} = 0.6$. Our results are in good agreement with various experimental constraints and observational data, particularly with the GW170817 data.