IV.T141 — Proton-Neutron Mass Difference — Tree Level [SUPERSEDED]

SUPERSEDED by IV.T142 (two-sector formula at +33 ppm). Tree-level: (m_n-m_p)/m_n = (sqrt(3)/2)*iota^6 at -5516 ppm. Retained for historical reference; IV.T142 is the canonical p-n mass formula.