The Evolution of Skyrme’s Approach

It was one of Tony Skyrme’s characteristic features to work in close contact with experimental physicists, who interested him in different phenomenological problems. In this way Skyrme was involved in solving the experimental data puzzle, which arose as a result of the fast electron scattering experiments, conducted with the aim of studying the charge distribution within the nucleus (the results werepublished in 1953). As a consequence of those electromagnetic type experiments, as well as from μ-mesonic atoms spectroscopy data or from the isotopic shift data, the value for the radius of the charge distribution within the nucleus was suggested to be $$ \bar R \simeq 1.2A^{1/3} fm $$ (1.1) where, as usual, A is the atomic number. At the same time it was already known from specifically nuclear type experiments such as α-decay, light nuclei reactions, from the penetrability factors calculated for the scattering of neutrons, or from the evidence of the difference in binding energies of mirror nuclei, that one can derive the value for the radius of the nucleus close to $$ \bar R \simeq 1.5A^{1/3} fm $$ (1.2) In combination, these results signified that the electrical charge of the nucleus lies within the radius \( {\bar R} \) but that the specifically nucleonic interactions extend out to the radius R.