Hadrons in nuclear medium and Κ+ scattering on nuclei

The ratio RT of K+ - 12C to K+ - d total cross sections has been calculated microscopically using a boson-exchange KN amplitude taking into account the modification of the nucleon Dirac spinor in nuclear matter and the coupling of the δ, ω and ρ fields to the polarisation of the nuclear medium. We find that the ratio RT is sensitive to these in-medium modifications of the nucleons and mesons properties, but the agreement with experimental data is worse than when the free-space KN interaction is used. However these effects are important and must be included in the calculations. (authors)