title: Electromagnetic self-energy contribution to M(p)-M(n) and the isovector nucleon magnetic polarizability.
abstract: We update the determination of the isovector nucleon electromagnetic self-energy, valid to leading order in QED. A technical oversight in the literature concerning the elastic contribution to Cottingham's formula is corrected, and modern knowledge of the structure functions is used to precisely determine the inelastic contribution. We find δM(p-n)(γ) = 1.30(03)(47)   MeV. The largest uncertainty arises from a subtraction term required in the dispersive analysis, which can be related to the isovector magnetic polarizability. With plausible model assumptions, we can combine our calculation with additional input from lattice QCD to constrain this polarizability as: β(p-n) = -0.87(85)×10(-4)  fm3.
authors.affiliation: Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: André
authors.initials: A
authors.lastname: Walker-Loud
authors.forename: Carl E
authors.initials: CE
authors.lastname: Carlson
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Miller