On the relation between electron and proton-nucleus scattering at high momentum transfer

Abstract

In proton-nucleus scattering, it is understood that the proton undergoes several scatters by the nucleus before being detected at some fixed momentum transfer. This is in contrast to the case of electron scattering from the same nucleus at the same momentum transfer. It is therefore expected that the proton-nucleus as compared to the electron-nucleus scattering is much less sensitive to the relatively short-distance behaviour of the nuclear density distribution. The purpose of this paper is to point out that very recent data on both proton and electron elastic scattering on nickel-58 at large momentum transfer can be related only if proper account of the short-distance behaviour of the scattering is taken into account in both cases. We show a similar tendency for the inelastic scattering at large momentum transfer. As these measurements for both electron and proton have been made for only very few nuclei at this time, we regard our conclusion in these regards to be suggestive but not yet conclusive. Elastic-electron -scattering measurements have been made (1.3) for nickel-58 up to a momentum transfer q = 2.8 fm -1. A good fit to the data was obtained with a charge density function of the form of a Fermi density with three parameters (4,5)