Exchange Electrical Moments for Nuclear Beta and Gamma Transitions

Abstract

The relative importance of exchange electric currents in nuclear beta and gamma transitions is estimated by using their relation to the Van Vleck potential and to the sum rule for nuclear photoabsorption cross section. Though the exchange electric currents are not experimentally observable because of the Siegert theorem, the estimates give us an idea of the difference between a free nucleon and a nucleon inside a nucleus. It is found that the magnitude of the exchange electric current relative to the convection current is more than 40% at the Fermi surface.