Analysis of exchange terms in a projected extended random phase approximation theory applied to the quasielastic (e,e') reaction

Abstract

A systematic study of the influence of exchange terms in the longitudinal and transverse nuclear response to quasielastic ( e , e ′ ) reactions is presented. The study is performed within the framework of the extended random phase approximation, which in conjuction with a projection method permits a separation of various contributions tied to different physical processes. The calculations are performed in nuclear matter up to second order in the residual interaction for which we take a ( π + ρ ) model with the addition of the Landau-Migdal g ′ parameter. Exchange terms are found to be important only for the random-phase-approximation-type contributions around the quasielastic peak.