K+-nucleus potentials from K+-nucleon amplitudes

Abstract

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.