Phenomenology of K+-nucleus scattering

A density expansion of the K+-nucleus optical potential is used within a momentum-space approach to analyze the experimental total and elastic differential cross section data. We add to the microscopic first-order optical potential a phenomenological higher-order term proportional to the nucleon density raised to a power α. A fit to the total cross section data yields a value for α of 2.85±0.25 and a strength for the potential that decreases slightly faster than the inverse of the kaon laboratory momentum. To obtain a higher-order potential compatible with all the data and with parameters that are target independent, a renormalization of the differential cross section data by 30%, consistent with our estimate of systematic errors, is made. The need for such a large renormalization is explained. copyright 1999 The American Physical Society