Effect of Electromagnetic Corrections to Low-Energy Nucleon-Nucleon Scattering on Charge Independence

Abstract

The low-energy nucleon-nucleon scattering lengths are calculated, taking into account the electric charge and magnetic-moment distributions of the nucleons. Corrections in the one-pion exchange part of the effective nuclear interaction due to the charged and uncharged pion mass difference are also included. The singlet proton-proton, proton-neutron, and neutron-neutron scattering lengths are calculated and compared with experiment. These corrections reduce the discrepancy to be explained by other effects in order to maintain charge independence. We conclude that recent measurements of the neutron-neutron scattering length do not contradict the hypothesis of charge independence.