Density dependence of single-proton and two-proton knockout reactions under quasifree conditions

We consider high-energy quasifree single- and two-proton knockout reactions induced by electrons and protons and address the question of what target-nucleus densities can be effectively probed after correcting for nuclear attenuation (initial- and final-state interactions). Our calculations refer to ejected proton kinetic energies of 1.5 GeV, the reactions (e,e'p), (γ,pp), and (p,2p), and a carbon target. It is shown that each of the three reactions is characterized by a distinctive sensitivity to the density of the target nucleus. The bulk of the (γ,pp) strength stems from the high-density regions in the deep nuclear interior. Despite the strong attenuation, sizable densities can be probed by (p,2p) reactions provided that the energy resolution allows one to pick nucleons from s orbits. The effective mean densities that can be probed in high-energy (e,e'p) reactions is of the order of 30%-50% of the nuclear saturation density.