IV.D372 — m_u/m_d Isospin NLO Structure

m_u/m_d NLO: (1/2-2ι_τ/17)·(1+(5/8)·ι_τ^(14/5))=0.4740 at +29 ppm from FLAG 0.474. LO: 1/2-2ι_τ/17=0.4598 at -29860 ppm. NLO prefactor 5/8=W₃(4)/lobes³, exponent 14/5 structurally non-trivial but not derived.