64 research outputs found
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 scattering from nuclei
The ratio of to cross sections has been calculated
microscopically using a boson-exchange amplitude in which the and
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 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 scattering from nuclei
In the calculation of the -nucleus cross sections, the coupling of the
mesons exchanged between the 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
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