Nuclear scattering of K+-mesons in the energy region of 80 MeV

The scattering of K+-mesons by nuclei of photoemulsion has been investigated in the 60 to 100 MeV region. Data on 27 collisions of K+-mesons with hydrogen nuclei, collected from various laboratories, are also presented. The angular distribution of the elastic scatterings is compared with curves calculated byCostaandPatergnanifor an optical model of the nucleus. The inelastic scattering data are, instead, compared with the results of a calculation performed with the Monte Carlo method, for a Fermi-gas nuclear model. Experimental evidences, such as the frequent occurrence of small angle elastic scatterings and the rarity of large energy losses, argue in favour of a repulsive nuclear potential acting on the K+-meson. The angular distribution of the K+-p collisions is then satisfactorily described assuming a predominants-wave scattering for energies lower than ∼ 50 MeV in the center of mass system. The data on the K+-nuclei inelastic scattering are shown instead to be well described, on the basis of the Fermi model, with the assumption that the K-nucleon cross-section is peaked backwards or is energy dependent. The influence of the two isotopic spin states which intervene in the K-nucleon scattering is discussed.