Medium effects in K-nuclear interactions

A self-consistent derivation of K⁺ nucleus integral cross sections from transmission experiments at p_L = 500 - 700 MeV/c is reviewed, including a table of updated total and reaction cross section values. The density dependence of the imaginary part of the self-consistent K-nucleus optical potential suggests that major in-medium reaction channels exist which are unaccounted for in dense nuclear media by the multiple-scattering V_opt = tρ optical potential and its straightforward, relatively minor modifications for kaon interactions. This observation is supported also by analyzing the recently measured K⁺ elastic scattering differential cross sections on ⁶Li and C, and it is not in conflict with the inelastic angular distributions measured in the same experiment. Previously proposed medium effects which are briefly recalled cannot be reconciled with the new data.