Electromagnetic Effects in Two-Nucleon Systems

Corrections to the electromagnetic properties of two-nucleon systems are examined by means of the relativistic two-body equation. An effective addition to the potential is derived, which describes the properties of the system in an external electromagnetic field. In particular, the correction to the deuteron's quadrupole moment is evaluated to lowest order in the meson-nucleon coupling. The result, for pseudoscalar (pseudoscalar) symmetric theory, is $\Delta Q=-1.3\mathrm{}\times {10}^{-28\mathrm{}}\left(\frac{g^2}{4\pi }\right)$ ${\mathrm{cm}}^2$.