Meson-exchange currents including energy transfer effects

Abstract

The standard formalism of meson-exchange currents is extended to incorporate energy transfer effects. It is possible to make such an extension, in a chirally invariant way, for several exchange currents including those involving an intermediate isobar. It is found that the “extended” currents still satisfy conservation of the polar vector current (CVC) and partial conservation of the axial vector current (PCAC) where appropriate. The hypothesis of axial locality is found to be valid for the currents considered. Deuteron photodisintegration at intermediate energies is then used to illustrate the numerical importance of the energy transfer effects. A brief survey is carried out for other reactions where the inclusion of energy transfer effects in the evaluation of selected meson-exchange currents is believed important.