We analyse the production and propagation of kaons and antikaons in Ni + Ni reactions from 0.8-1

We investigate theDN interaction at low energies using a meson-exchange model supplemented with a short-distance contribution from one-gluon-exchange. The model is developed in close analogy to the meson-exchange KN interaction of the Jülich group utilizing SU(4) symmetry constraints. The main ingredients of the interaction are provided by vector meson (ρ, ω) exchange and higher-order box diagrams involvingD * N ,D∆, andD * ∆ intermediate states. The short range part is assumed to receive additional contributions from genuine quark-gluon processes. The predicted cross sections forDN for excess energies up to 150 MeV are of the same order of magnitude as those for KN but with average values of around 20 mb, roughly a factor two larger than for the latter system. It is found that the ω-exchange plays a very important role. Its interference pattern with the ρ-exchange, which is basically fixed by the assumed SU(4) symmetry, clearly determines the qualitative features of theDN interaction -very similiar to what happens also for the KN system. PACS. 14.40.Lb Charmed mesons -12.39.Pn Potential models -12.40.-y Other models for strong interactions -13.75.Jz Kaon-baryon interactions

Abstract. We examine the production of open charm in antiproton annihilation on finite nuclei. The enhancement of the subthreshold production cross section, even in a nucleus as light as carbon, should provide a clean signature of the reduction in the masses of these mesons in-medium. We also show that a careful analysis of the D + and D − spectra can yield important information on the cross section for D ± N scattering.

The energy dependence of the total kaon production cross sections in baryon baryon (N and ∆) collisions are studied in the resonance model, which is a relativistic, tree-level treatment. This study is the first attempt to complete a systematic, consistent investigation of the elementary kaon production reactions for both the pion baryon and baryon baryon reactions. Our model suggests that the magnitudes of the isospin-averaged total cross sections for the N N → N Y K and ∆N → N Y K (Y = Λ or Σ) reactions are almost equal at energies up to about 200 MeV above threshold. However, the magnitudes for the ∆N reactions become about 6 times larger than those for the N N reactions at energies about 1 GeV above threshold. Furthermore, the magnitudes of the isospin-averaged total cross sections for the N N → ∆Y K reactions turn out to be comparable to those for the N N → N Y K reactions at N N invariant collision energies about 3.1 GeV, and about 5 to 10 times larger at N N invariant collision energies about 3.5 GeV. The microscopic cross sections are parametrized in all isospin channels necessary for the transport model studies of kaon production in heavy ion collisions. These cross sections are then applied in the relativistic transport model to study the sensitivity to the underlying elementary kaon production cross sections.

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