Nuclear Binding Effects in Relativistic Coulomb Sum Rules

Abstract

We extend the formulation of relativistic Coulomb sum rules to account for the average effects of nuclear binding on the initial and final states of ejected nucleons. Relativistic interactions are included by using a Dirac representation adapted from a vector-scalar field theory. The scalar field reduces the effective nucleon mass $M^*$ and increases the relativistic effects of recoil and Fermi motion. We consider two models for the off-shell behavior of the nuclear electromagnetic current, and demonstrate that the sum rule is accurate for applications to data over the interesting range of $M^*$ and three momentum $q$. We further indicate that the form of the sum rule is sufficiently general to accommodate a broad class of off-shell form factor models.