Quasifree scattering in the preequilibrium region

A model for inclusive proton-nucleus scattering which covers the preequilibrium region is developed based on (1) single-step quasifree scattering and (2) the exciton model, which describes emission from 3p2h and higher configurations. Results are compared to data for various nuclei at incident energies from 60 to 200 MeV. The systematics of angle-dependent energy spectra are well reproduced by the model, except in the large-energy-loss region at very forward angles. We find the single-step quasifree scattering constitutes 60% to 80% of the reaction cross section in medium-heavy nuclei, and about 50% in heavy nuclei. The preequilibrium region is therefore dominated by direct single-step reactions