Kaon meson condensate in neutron star matter including hyperons

TL;DR

This paper investigates how kaon condensation affects the properties of neutron stars, demonstrating that with appropriate parameters, neutron stars with kaon condensates can exceed 2 solar masses, aligning with recent observations.

Contribution

It introduces a modified relativistic mean field model with a sigma-cut scheme to accurately model massive neutron stars with kaon condensates.

Findings

Kaon condensation influences neutron star maximum mass.

Proper parameter choices allow neutron stars with kaon condensates to surpass 2 solar masses.

The rho-omega interaction parameter significantly affects kaon condensation.

Abstract

The recent measurement of the mass of neutron stars (PSR J1614 - 2230, PSR J0348 + 0432, MSP J0740 + 6620) restricts the lower limit $\sim 2M_{\odot}$ of the maximum mass of such compact stars, making it possible for dense matter to exist in massive stars. The relativistic mean field theory with parameter sets FSUGold including Kaon condensation is used to describe the properties of neutron stars in $\beta$ equilibrium. Through careful choice of the parameter of the $\sigma$-cut $c_{\sigma}$, we are able to produce a maximum mass neutron star with Kaon condensation heavier than $2M_{\odot}$, and we find that the parameter $\Lambda_{\nu}$ of the $\rho-\omega$ interaction term in this model has a significant effect on $K^{-}$ condensation. In the case of using $\sigma$-cut scheme, $K^{-}$ condensation occurs only when the $\rho-\omega$ interaction $\Lambda_{\nu}$ is switched off.