K+ PRODUCTION IN PROTON AND DEUTERON INDUCED REACTIONS AT SUBTHRESHOLD ENERGIES

The production of K+ mesons in proton-nucleus and deuteron-nucleus col lisions is analyzed with respect to one-step nucleon-nucleon (NN --> N LAMBDAK+), DELTA-nucleon (DELTAN --> NLAMBDAK+) and two-step pion-nucl eon (piN --> K+ LAMBDA) production channels on the basis of experiment al ground state momentum distributions and free on-shell production pr ocesses. Whereas for K+ production in proton-nucleus reactions the sec ondary channel piN clearly dominates at subthreshold energies, meson a nd nucleon induced channels are of similar magnitude in deuteron-nucle us reactions. Contrary to nucleus-nucleus collisions the DELTA induced reaction channels are found to be of minor importance. The experiment al differentiation of the underlying microscopic reaction channels app ears possible via differential proton - K+ coincidence measurements as shown in detail by the microscopic simulations including proton resca ttering.