PI-0 ELECTROMAGNETIC SELF-ENERGY AND ITS IMPLICATIONS FOR INCORPORATING ELECTROMAGNETISM IN FEW-BODY SYSTEMS

By investigating the electromagnetic (EM) chiral series for the pseudo scalar mesons at next-to-leading order, it is shown that the pi0 EM se lf-energy is O(alpha(EM)m(u,d)), and hence small. This observation com pletes the crucial step in an earlier argument, which employed previou sly the vanishing of the pi0 EM self-energy in the chiral limit, and w hich demonstrates that the effects of not only one-photon-exchange- bu t also one-photon-loop graphs must be included in order to incorporate the effects of electromagnetism in hadronic systems.