The following 21 pp. paper by H. Aspden was published in 1974 by Sabberton Publications, P.O. Box 35 Southampton SO16 7RB, England.
Abstract: The atomic nucleus is shown to have a form determined by the quantum structure of a Dirac-style vacuum. Nucleons occupy a series of holes in the structured vacuum forming a shell about a core region of unoccupied holes. These nucleons are linked by chains of electron-positron composition. The lattice spacing can be related to the binding energy of the nucleus in precise quantitative terms. The special position of Fe 56 in the nuclear packing fraction curve is explained in terms of the cubic symmetry of the lattice system, the optimization of interaction energy with the core charge and the energy minimization of the chains.
Commentary: This paper developed the nuclear theme introduced in chapter 7 of the author's 1969 book 'Physics without Einstein'. The author had explored the foundations of proton creation theory in that work and had found a role for the pion in serving as a nuclear binding agent within the nuclear structure. However, much stronger evidence had emerged to suggest that a dimuon mass quantum was needed to replace the pion in the earlier model. This gave basis for the statement:
"A very important advance emerges if we take the equation (7.9) [from 'Physics without Einstein'] and find the solution which gives maximum surplus energy. Thus we put the expression at a minimum with M set at 1836m and Mo variable. Simple analysis then shows that for this condition Mo is M(3/2)1/2)M or 0.225M or 413m."Noting that a muon pair has a combined mass of 413m, this was the starting point for a major breakthrough in understanding proton creation from a muon lepton field background. See the Physics Today reference [1984f].