Relativistic analysis of meson exchange currents in elastic electron-deuteron scattering

Abstract

The ρπγ and ωɛγ meson exchange current contributions to the deuteron form factors are calculated in a relativistic quasipotential one-boson-exchange model. Recoil corrections to the two-body EM current operator are kept. It is shown that a substantial reduction of the ρπγ graph occurs especially at high momentum transfer as compared to the usual nonrelativistic treatment, where only leading-order terms in p/M are retained. As a consequence, the ωɛγ contribution becomes also important at high momentum transfer. Using the value for the ωɛγ coupling constant from a relativistic quark model, the elastic EM form factors are predicted in reasonable accordance with the experimental data.