Interplay of antikaons with hyperons in nuclei and in neutron stars

Muto, Takumi*; Maruyama, Toshiki  ; Tatsumi, Toshitaka*

Possible coexistence of antikaons and hyperons in nuclei and in neutron stars is investigated based on the same interaction model within the relativistic mean-field theory. It is shown that the ground state of multi-strangeness nuclei is given by multi-hypernuclei without bound mesons. In neutron stars, on the other hand, kaon condensation appears in hyperon-mixed matter for a moderate potential depth, but it leads to significant softening of the equation of state. Some repulsive effect at high density should be taken into account so as to be consistent with recent observations of massive neutron stars.