Transport analysis of K+ production in proton-nucleus reactions

Abstract.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 (CBUU) transport approach 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-Jülich. 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.