Effects of medium-modified form factors in quasielastic electron scattering from 12C.

Abstract

We present calculations of the longitudinal and transverse response functions for (e,e') inclusive reactions on $^{12}\mathrm{C}$. The calculations are made in the impulse approximation and use the medium-modified electromagnetic form factors of the nucleon which we calculated recently. Most of our calculations were made using a Fermi-gas model, however, we also present results for calculations which make use of wave functions of a finite-nucleus model. (In the latter case we include the medium-modified form factors in a local-density approximation.) One finds a very good fit to the longitudinal response using the medium-modified form factors. The fit to the transverse response is less satisfactory and indicates the presence of a significant amplitude in the response which is not described by the quasielastic nucleon-knockout mechanism. The fit of the longitudinal response achieved here suggests that the nucleon form factor is modified in the medium. These calculations support similar conclusions we have drawn from our study of the longitudinal response functions of $^{56}\mathrm{Fe}$ and $^{40}\mathrm{Ca}$.