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

Abstract

The properties of the kaon, $K$, and antikaon, $\kbar$, 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 $\kbar$ mesons. It is demonstrated that the $\rho$ meson induces different mean field potentials for each member of the isodoublets, $K$ and $\kbar$, when they are embedded in asymmetric nuclear matter. Furthermore, it is also shown that this $\rho$ meson potential is repulsive for the $K^-$ meson in matter with a neutron excess, and renders $K^-$ condensation less likely to occur.Comment: Latex, 11 pages, 4 Postscript figures, a few typos which can be important for an interpretation (but not reflected in the results) are corrected, as published in (E) Phys. Lett. B 436 (1998) 45

QCD Symmetries in $\eta $- and $\eta '$-Mesic Nuclei

“…reduction in the K − mass of about 100 MeV at nuclear matter density and interpretation of the Λ(1405) resonance as dynamically generated in the kaon-nucleon system [39,37]. An effective mass drop of the K − to about 270 MeV at 2ρ 0 has been observed in heavy-ion collisions [40], consistent with the predictions of the Quark Meson Coupling and chiral coupled channels model calculations.…”

Kaon properties and cross sections in the nuclear medium

“…Studies with a variety of models [3,4] indicate that the antikaon potential is attractive while the kaons feel a repulsive potential in nuclear matter. However, the analysis of available data on K + production from heavy ion collisions at SIS energies [5,6] contradicts the predictions that the kaon potential is repulsive.…”

“…We calculate the in-medium reaction amplitudes, taking into account the scalar and vector potentials for incident, final and intermediate mesons and baryons. and antiquarks in the hadron bags (q = u,ū, d ord, hereafter), neglecting the Coulomb force, are given by [4]:…”

“…In view of its numerous successful applications elsewhere, we base our estimate on the QMC model [4,12], and use those estimated values [1] for the in-medium resonance masses.…”

Medium modifications of baryon properties in nuclear matter and hypernuclei

“…To obtain the mass difference between Λ and Σ, we take into account the spin-dependent interactions between quarks by adding E B spin in Eq. (11). Then the effective baryon mass is given by M *…”