K+-nucleus potentials from K+-nucleon amplitudes

Optical potentials for K⁺-nucleus interactions are constructed from K⁺-nucleon amplitudes using recently developed algorithm based on K⁺-N kinematics in the nuclear medium. With the deep penetration of K⁺ mesons into the nucleus at momenta below 800 MeV / c it is possible to test this approach with greater sensitivity than hitherto done with K^- and pions. The energy-dependence of experimental reaction and total cross sections on nuclei is better reproduced with this approach compared to fixed-energy amplitudes. The inclusion of Pauli correlations in the medium also improves the agreement between calculation and experiment. The absolute scale of the cross sections is reproduced very well for ⁶Li but for C, Si and Ca calculated cross sections are (23 ± 4)% smaller than experiment, in agreement with earlier analyses. Two phenomenological models that produce such missing strength suggest that the imaginary part of the potential needs about 40% enhancement.