IV.R394 — Comparison to Cottingham decomposition

Orthodox: EM~0.63 MeV + QCD~0.66 MeV = 1.29 MeV. Tau C.5: EM~0.120 MeV + QCD~1.413 MeV = 1.293 MeV. Factor-5 EM discrepancy: fractional quark charges (alpha/3) account for factor 3; remaining factor involves vector meson dominance renormalization.