Pion Production, Pion Absorption and Nucleon Properties in Dense Nuclear Matter: The Relativistic Dirac-bruckner Approach at Intermediate-energies and High-energies

ithin the relativistic Dirac-Brueckner approach we discuss the properties of highly-energetic nucleons and deltas in dense nuclear matter. The effective NN and NΔ interactions are constructed in a fully self-consistent way and reproduce all known properties of nuclear matter. We calculate the nucleon self-energy and the density-dependent effective NN and NΔ cross sections in a nuclear medium. Results show a sizable reduction of the Δ (pion) production cross section and important changes in the Δ absorption cross section