The production of K+ mesons in proton-nucleus collisions from 1.0 to 2.3
GeV is analyzed with respect to one-step nucleon-nucleon (NN→NYK+) and
two-step Δ-nucleon (ΔN→K+YN) or pion-nucleon (πN→K+Y) production channels on the basis of a coupled-channel transport
approach (CBUU) including the kaon final-state-interactions (FSI).
Momentum-dependent potentials for the nucleon, hyperon and kaon in the final
state are included as well as K+ elastic rescattering in the target nucleus.
The transport calculations are compared to the experimental K+ spectra taken
at COSY-J\"ulich. Our systematic analysis of K+ spectra from 12C,
63Cu, 107Ag and 197Au targets as well as their momentum
differential ratios gives a repulsive K+ potential of 20±5 MeV at
normal nuclear matter density.Comment: 7 pages, 5 figures, submitted to Eur. Phys. J.