Longitudinal and transverse spin responses in relativistic many-body theory

Abstract

We study theoretically the spin response functions using the relativistic many-body theory. The spin response functions in the relativistic theory are reduced largely from the ones of the non-relativistic theory, in particular the longitudinal spin responses. This fact enables us to remove the difficulty in reproducing the ratio of the longitudinal and transverse response functions seen experimentally. We use the local density approximation with the eikonal prescription of the nuclear absorption on the incoming and outgoing nucleons for the calculations of the response functions of finite nuclei. We compare the calculated results with the recent experimental results with ( p, n ) reactions on C and Ca.