IV.R344 — Charge Conjugation Selection Rule --- IV.R12

The vanishing of odd-alpha corrections to R is a structural selection rule from the bipolar decomposition: C-invariance forces chi_+ and chi_- to contribute symmetrically, electromagnetic mass corrections are proportional to sum(q_i^2) not sum(q_i), and q_i^2 is invariant under charge conjugation, so only even powers survive.