Some time back I'd detailed how the nuclear 'Aufbau' operated, with the formula 2n+l, rather than the n+l we see with the electronic Aufbau. The nuclear version is linked to the fact that for shells, all 'orbitals' must be of the same parity, as opposed to the alternating parity seen in the electronic system.
But unlike the electronic system nobody has ever ascribed 'lobes' to the nucleus, which HAS no central dense core. Rather we see the nucleus as approximating (for most nuclides, anyway) ellipsoids of various stripes. Rare nuclides might have one or more nucleons orbiting the main body, while the individual nucleons IN the main body are supposed largely to remain in the same contact positions with others.
This leads me to wonder now whether the notion of orbit, for nucleons, is less about probabilistic appearance in abstract fuzzy orbitals, and more concrete. If a nucleus rotates, as it must if a deformed ellipsoid, then all nucleons inside it will also describe closed paths, but not necessarily all of the same ones. It is as if they might be tunneling through the main body of the nucleus. This might be thought of as an inversion of what takes place in the electronic cloud. In the latter, electrons never touch, in the former, they must (due to the strong force). But the dance partners keep switching (one partner is as good as any other), though there is a tendency for protons to migrate towards the periphery of the nucleus, due to their mutual repulsion.
I'm also wondering if my hypothesized 'tunneling' effect could be relatable to the 'intruder' phenomenon, where the highest-spin orbital partials from the next-higher shell get stabilized enegetically and are inserted into the structure of the previous shell at points defined by Pascal Triangle combinatorics (specifically doubled triangular numbers of moves from where they *should* be relative to the LS structure of harmonic oscillator shells without spin-orbit effect). Insertion seems like tunneling, at least in part.
Remember also that while the electronic orbitals fill halfway singly before allowing opposed-spin partners within lobe (except for s, which isn't considered a 'lobe'), nucleons pair up IMMEDIATELY upon getting to an even number. Why the difference? In any case, because of this difference, there is no half-filled orbital effect in nuclei. Instead, we see nuclei with even numbers of nucleons more stable overall than those with odd numbers.
Jess Tauber