In this work, we study the effect of (anti)kaon condensation on the properties of compact stars that develop hypernuclear cores with and without an admixture of $\mathrm{\Delta }$-resonances. We work within the covariant density functional theory with the parameters adjusted to $K$-atomic and kaon-nucleon scattering data in the kaonic sector. The density-dependent parameters in the hyperonic sector are adjusted to the data on $\mathrm{\Lambda }$ and ${\mathrm{\Xi }}^{-}$ hypernuclei data. The $\mathrm{\Delta }$-resonance couplings are tuned to the data obtained from their scattering off nuclei and heavy-ion collision experiments. We find that (anti)kaon condensate leads to a softening of the equation of state and lower maximum masses of compact stars than in the absence of the condensate. Both the $K^{-}$ and ${\overline{K}}^0$ condensations occur through a second-order phase transition, which implies no mixed-phase formation. For large values of (anti)kaon and $\mathrm{\Delta }$-resonance potentials in symmetric nuclear matter, we observe that condensation leads to an extinction of ${\mathrm{\Xi }}^{-,0}$ hyperons. We also investigate the influence of inclusion of additional hidden-strangeness ${\sigma }^{*}$ meson in the functional and find that it leads to a substantial softening of the equation of state and delay in the onset of (anti)kaons.

• Received 14 January 2021
• Accepted 6 February 2021

DOI:https://doi.org/10.1103/PhysRevD.103.063004