We calculate the elastic and inelastic ωN →ωN , →πN , →ρN , →ρπN , →ππN , →σN reactions within a boson exchange approximation where the ωρπ coupling constant and form factor are fixed by the reaction πN →ωN in comparison to the experimental data. We find rather large ωN cross sections at low relative momenta of the ω-meson which leads to a substantial broadening of the ω-meson width in nuclear matter. The implications of the ωN final state interactions are studied for ω production in 12 C+ 12 C, 40 Ca+ 40 Ca and 58 N i+ 58 N i reactions at about 2·A GeV within the HSD transport approach; the drastic changes of the transverse mass spectra relative to a general mT -scaling (for π 0 and η mesons) might be controlled experimentally by the TAPS Collaboration.

We reanalyse the production of pp pairs in proton-nucleus and nucleus-nucleus collisions employing novel elementary cross sections for baryon-baryon and pionbaryon production channels based on a boson-exchange model. In contrast to previous transport studies performed in the literature the secondary pion induced channel is found to be most important in both p+A and A+A collisions at subthreshold energies. A detailed comparison with the experimental data available indicates that sizeable attractivep potentials in the order of -100 to -150 MeV at normal nuclear matter density are needed to reproduce the size and shape of the experimental spectra. * Supported by Forschungszentrum Jülich, BMBF and the Russian Foundation for Fundamental Research

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The production of antiprotons in pp collisions is investigated close to threshold where experimental data about the total cross section are not available. We analyze the latter reaction within the LUND string model for inclusivep production and within the framework of a one-boson exchange model for the exclusive reaction pp → pppp. The application of our new results to the analysis of subthreshold antiproton production in d + p and d + d collisions shows cross sections that are much lower than expected before. Nevertheless, the comparison of experimentalp differential cross sections from d+ p and d+ d is expected to provide valuable information about a nonnucleonic component in the deuteronwavefunction. * supported by BMBF and the Russia Foundation for the fundamental Research