Thomas, A.Wang, X.Young, R.2016-09-082016-09-082015Physical Review C: Nuclear Physics, 2015; 91(1):015209-1-015209-40556-28131089-490Xhttp://hdl.handle.net/2440/101023We study the electromagnetic contribution to the proton-neutronmass splitting by combining lattice simulations and the modified Cottingham sum rule of Walker-Loud, Carlson, and Miller. This analysis yields an estimate of the isovector nucleon magnetic polarizability as a function of pion mass. The physical value, obtained by chiral extrapolation to the physical pion mass, is βp-n= (−1.12 ± 0.40) × 10−4 fm3,, which is in agreement with the empirical result, albeit with a somewhat smaller error. As a result, we find δMγ p-n= 1.04 ± 0.11 MeV, which represents a significant improvement in precision.en©2015 American Physical SocietyJournal article003002708410.1103/PhysRevC.91.0152090003512675000042-s2.0-84961290488183697Thomas, A. [0000-0003-0026-499X]Wang, X. [0000-0001-9164-0027]Young, R. [0000-0002-4527-1811]