Kaon meson condensate in neutron star matter including hyperons
Fu-Long Ma, Wenjun Guo, Chen Wu
Abstract
The recent measurement of the mass of neutron stars (PSR J1614\ensuremath{-}2230, PSR J0348+0432, MSP J0740+6620) restricts the lower limit $\ensuremath{\sim}2{M}_{\ensuremath{\bigodot}}$ 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 $\ensuremath{\beta}$ equilibrium. Through careful choice of the parameter of the $\ensuremath{\sigma}$-cut ${c}_{\ensuremath{\sigma}}$, we are able to produce a maximum mass neutron star with kaon condensation heavier than $2{M}_{\ensuremath{\bigodot}}$, and we find that the parameter ${\mathrm{\ensuremath{\Lambda}}}_{\ensuremath{\nu}}$ of the $\ensuremath{\rho}\ensuremath{-}\ensuremath{\omega}$ interaction term in this model has a significant effect on ${K}^{\ensuremath{-}}$ condensation. In the case of using the $\ensuremath{\sigma}$-cut scheme, ${K}^{\ensuremath{-}}$ condensation occurs only when the $\ensuremath{\rho}\ensuremath{-}\ensuremath{\omega}$ interaction ${\mathrm{\ensuremath{\Lambda}}}_{\ensuremath{\nu}}$ is switched off.