On the density dependence of single-proton and two-proton knockout reactions under quasifree conditions

TL;DR

This paper investigates how different high-energy quasifree reactions can probe various density regions within nuclei, revealing their sensitivity to nuclear interior densities after accounting for attenuation effects.

Contribution

It provides a comparative analysis of (e,e'p), (gamma,pp), and (p,2p) reactions, highlighting their unique sensitivities to nuclear density distributions.

Findings

(gamma,pp) predominantly probes high-density regions

(p,2p) can access sizable densities with good energy resolution

(e,e'p) effectively probes 30-50% of nuclear saturation density

Abstract

We consider high-energy quasifree single- and two-proton knockout reactions induced by electrons and protons and address the question 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), (\gamma,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 (\gamma,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) 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) are of the order of 30-50% of the nuclear saturation density.