SubthresholdK + production in proton-nucleus collisions

We analyzed theK⁺ production at projectile energies below the free nucleon-nucleon threshold in proton-nucleus collisions and studied the contribution from different reaction channels to this process. It was shown that the secondary pion-nucleon (+N+K⁺) channel significantly prevails over the direct (p+N+N+K⁺) one. The momentum and angularK⁺ spectra were calculated in the framework of different production channels in order to propose experimental measurements which allow to distinguish the mechanisms discussed. We also studiedK⁺d correlations and considered the deuteron reabsorption in the nuclear medium as well as the fast deuteron background. The features ofK⁺p correlations related to the different production channels were analyzed as well.