Saturation properties of nuclear matter in a relativistic mean field model constrained by quark dynamics

We have built an effective Walecka-type hadronic Lagrangian in which the hadron masses and the density dependence of the coupling constants are deduced from the quark dynamics using a Nambu-Jona-Lasinio model. The parameters of this Nambu-Jona-Lasinio model have been determined using the meson properties in the vacuum but also in the medium through the omega meson mass in nuclei measured by the TAPS collaboration. Realistic properties of nuclear matter have been obtained.Comment: 4 pages, 1 figure, to appear in the Proceedings of "Quark Confinement and the Hadron Spectrum VII

Dirac sea effects in K+K^+ scattering from nuclei

The ratio $R_T$ of $K^+-^{12}C$ to $K^+-d$ cross sections has been calculated microscopically using a boson-exchange $KN$ amplitude in which the $\sigma$ and $\omega$ mesons are dressed by the modifications of the Dirac sea in nuclear matter. In spite of the fact that this dressing leads to a scaling of the mesons effective mass in nuclear matter, the effect on the $R_T$ ratio is found to be weak.Comment: 8 pages, LaTeX, 2 figures available upon request, LPTB-93-

Polarization of the nuclear medium and RPA-type calculations in K+K^+ scattering from nuclei

In the calculation of the $K^+$-nucleus cross sections, the coupling of the mesons exchanged between the $K^+$ and the target nucleons to the polarization of the Fermi sea has been taken into account. This polarization has been calculated in the one-loop approximation but summed up to all orders (RPA-type calculation). This effect is found to be rather important but does not improve the agreement with experiment.Comment: 11 pages, LaTeX, 3 figures available upon request, LPTB-93-

Saturation properties of nuclear matter in a relativistic mean field model constrained by the quark dynamics

We have built an effective Walecka-type hadronic Lagrangian in which the hadron masses and the density dependence of the coupling constants are deduced from the quark dynamics using a Nambu-Jona-Lasinio model. In order to stabilize nuclear matter an eight-quark term has been included. The parameters of this Nambu-Jona-Lasinio model have been determined using the meson properties in the vacuum but also in the medium through the omega meson mass in nuclei measured by the TAPS collaboration. Realistic properties of nuclear matter have been obtained.Comment: 14 pages, 2 figures, submitted to Nuclear Physics