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

摘要

The properties of the kaon, $K$, and antikaon, $\kbar$, in nuclear medium arestudied in the quark-meson coupling (QMC) model. Employing a constituentquark-antiquark (MIT bag model) picture, their excitation energies in a nuclearmedium at zero momentum are calculated within mean field approximation. Thescalar, and the vector mesons are assumed to couple directly to the nonstrangequarks and antiquarks in the $K$ and $\kbar$ mesons. It is demonstrated thatthe $\rho$ meson induces different mean field potentials for each member of theisodoublets, $K$ and $\kbar$, when they are embedded in asymmetric nuclearmatter. Furthermore, it is also shown that this $\rho$ meson potential isrepulsive for the $K^-$ meson in matter with a neutron excess, and renders$K^-$ condensation less likely to occur.