Hyperon-hyperon interactions and properties of neutron star matter

Abstract

We present results from Brueckner-Hartree-Fock calculations for $\ensuremath{\beta}$-stable neutron star matter with nucleonic and hyperonic degrees of freedom, employing the most recent parametrizations of the baryon-baryon interaction of the Nijmegen group. It is found that the only strange baryons emerging in $\ensuremath{\beta}$-stable matter up to total baryonic densities of 1.2 ${\mathrm{fm}}^{\ensuremath{-}3}$ are ${\ensuremath{\Sigma}}^{\ensuremath{-}}$ and $\ensuremath{\Lambda}.$ The corresponding equations of state are then used to compute properties of neutron stars such as masses and radii.