MOMENTUM-SPACE OPTICAL-MODEL FOR K-NUCLEUS SCATTERING()

The momentum-space optical model of K+-nucleus scattering is analyzed and comparison with other conventional models is shown. The model is b ased on the multiple scattering formalism in which the optimal factori zation approximation is used. Off-energy-shell extension of the elemen tary K+-nucleon amplitude is neglected which reduces non localities in the optical potential. Predictions of the model are sensitive to the definition of the K+-nucleon energy (energy shifts) but they are indep endent (1-2%) of a particular form of the covariant K+-nucleus scatter ing equation (relativistic Lippmann-Schwinger, Gross, Erkelenz-Holinde ). The Coulomb distortion in the total cross section is important for Si-28 and Ca-40 at low momenta (approximate to 10%). Off-energy-shell effects in the optical potential are discussed too. Results for the to tal and reaction cross sections are systematically below the data. The reaction cross sections are in a larger disagreement with the data th an the total cross sections.