Paper 108D: Shell-Offset Exchange-Renewal as a Qualitative Deuteron–Diproton Discriminator From Static Binding Wells to Renewing Finite-Distance Nucleon-Like Bonds

This paper develops a reduced-support diagnostic for nuclear binding within the Holosphere shell program. The test does not attempt to derive QCD, calculate the nuclear force, or reproduce the physical deuteron binding energy. Instead, it asks a narrower structural question: can a shell-offset exchange-renewal mechanism distinguish nucleon-like channels that should bind qualitatively from channels that should not? Earlier shell-ladder and activation tests showed that static activation or finite-distance well formation alone is too permissive, because broken cuboctahedral and off-ladder controls can imitate partial support behavior. Paper 108D therefore replaces a simple activation gate with a deuteron-diproton truth-table discriminator.

The V10 reduced-support sweep tests whether candidate shell channels form finite-distance wells, renew cleanly across an exchange cycle, remain centered away from the sampled distance boundary, and pass only when they behave as proton-neutron-like or composite proton-neutron-support channels. The central qualitative target is the deuteron-diproton contrast: proton-neutron-like support should be allowed to form a deuteron-like renewing bond, while proton-proton-like, neutron-neutron-like, broken-mirror, and off-ladder controls should be rejected.

At L = 16, complementary proton-neutron-like channels pass the deuteron-like discriminator with fraction 0.894387, and composite proton-neutron-support channels pass with fraction 0.614583. Same-positive, neutral-only, broken-mirror, and off-ladder controls produce zero deuteron-like passes. The strongest parameter regions show truth-positive fraction 1.000000, false-positive fraction 0.000000, and truth gap 1.000000 across adjacent high-performing regions.

These results support the local claim that shell-offset exchange-renewal can produce a qualitative deuteron-diproton discriminator in a reduced-support setting. The result is not presented as a derivation of QCD, the nuclear force, or the physical deuteron. It is a falsifiable structural bridge from shell geometry to finite-distance residual-binding behavior. The main conclusion is that static wells are not enough: a viable reduced nuclear-binding proxy must combine preferred spacing, complementary exchange, bounded renewal, and truth-table selectivity.