Current conserving random phase approximation: Implications and applications
The restrictions imposed by the continuity equation on the residual interaction of the current conserving RPA are examined in detail. Residual interactions in common use generally violate these conditions. Notable exceptions are those of zero range such as the Migdal and surface delta interactions, which satisfy the conditions exactly for unnatural parity states (e.g. magnetic excitations). A new current conserving parametrization of the residual interaction is proposed, which leaves previous results unchanged, whenever the interaction is current conserving. It is applied to12C,16O and40Ca, and the results are compared with those of the conventional RPA.