Proton and Neutron Densities in Nuclei

Abstract

The dominant interaction in nuclei is the strong, short-range, nuclear interaction. However, electromagnetic interaction does play an important role in the understanding of nuclear properties. For example, the decrease in the ratio of the number of protons to the number of neutrons in heavier nuclei is understood in terms of the repulsive electromagnetic interaction between the protons. Furthermore, when a proton is far away from the remaining nucleus, it experiences mainly the electromagnetic interaction. Therefore, the asymptotic behaviour of the wave functions and the densities is governed by the results in (2.15). Here we develop simple expressions for proton and neutron densities in nuclei and show that the surface properties of nuclei, such as surface thickness, can be understood in terms of the asymptotic behaviour of the density [110, 111].