In-medium kaon and antikaon properties in the quark-meson coupling model

The properties of the kaon, K, and antikaon, K̄, in nuclear medium are studied in the quark-meson coupling (QMC) model. Employing a constituent quark-antiquark (MIT bag model) picture, their excitation energies in a nuclear medium at zero momentum are calculated within mean field approximation. The scalar, and the vector mesons are assumed to couple directly to the nonstrange quarks and antiquarks in the K and K̄ mesons. It is demonstrated that the ρ meson induces different mean field potentials for each member of the isodoublets, K and K̄, when they are embedded in asymmetric nuclear matter. Furthermore, it is also shown that this ρ meson potential is repulsive for the K− meson in matter with a neutron excess, and renders K− condensation less likely to occur.