Kaon-baryon coupling schemes and kaon condensation in hyperon-mixed matter

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

The possible coexistence of kaon condensation and hyperons in highly dense matter is investigated. Two coupling schemes for the s-wave kaon-baryon interaction are compared regarding the onset density of kaon condensation in hyperon-mixed matter and the equation of state for the developed () phase. One is the contact interaction scheme related to the non-linear effective chiral Lagrangian. The other is the meson exchange scheme. It is shown that in the meson exchange scheme, the contribution from the non-linear scalar self-interaction gives rise to a repulsive effect for the kaon effective energy, pushing up the onset density of kaon condensation. The non-linear self-interacting term is not relevant to repulsive energy leading to stiffening of the EOS at high densities, and it cannot be compensated with a large attractive energy due to the appearance of the () phase in the case of the contact interaction scheme.