On Interpreting Related Magnetic Moments of Light Nuclei

Under the assumption that neutrons and protons are simple nuclear building stones, endowed with constant spin magnetic moments and bound together by simple short range interactions of an exchange (primarily space-exchange) nature, it is (a) not found possible to explain the order of magnitude of the observed difference between the magnetic moments of ${\mathrm{Li}}^6$ and the deuteron, without a very forced theory of spin-orbit coupling; (b) not understandable that the ${\mathrm{N}}^{14}$ and ${\mathrm{Li}}^6$ moments should differ considerably; (c) not possible to explain the difference between the magnetic moments of ${\mathrm{Li}}^7$ and the proton in the central-field model (with perturbations) within 25 percent, and not possible to reduce the smaller discrepancy in the alpha-particle model to less than four percent, unless the electric polarizability of the triton is much greater than estimated by the central-field model; (d) understandable in the central-field model that the ${\mathrm{F}}^{19}$ nucleus is in a ${}_{}{}^2{}_{}{}^{}S$ state with magnetic moment about five percent less than that of the proton, due to slight admixture of neutron spin; (e) possible to understand the observed angular momentum (sign of spin-orbit coupling) of ${\mathrm{N}}^{15}$ in either of the models. The discrepancies (a) and (c) are quite small and suggest especially that the intrinsic spin magnetic moments of protons and neutrons are constant to within a few percent, as does (d). The discrepancy (b) is larger but involves more particles. The discrepancies may plausibly be attributed either to influence of the binding forces on the spin magnetic moments, or perhaps to a term in the interaction containing the angles between the spin directions and the displacement vectors between the particles.