Eur. Phys. J. A (2003) 17: 451-455
https://doi.org/10.1140/epja/i2002-10191-8

Original Paper

Is the proton electromagnetic form factor modified in nuclei?

¹ CEA Saclay DSM/DAPNIA/SPhN, F91191, Gif-sur-Yvette Cedex, France
² Temple University, PA 19122, Philadelphia, USA

^* e-mail: morgen@hep.saclay.cea.fr

Abstract

Guided by the recent experimental confirmation of the validity of the Effective Momentum Approximation (EMA) in quasi-elastic scattering off nuclei, we have re-examined the extraction of the Longitudinal and Transverse Response Functions in medium-weight and heavy nuclei. In the EMA we have performed a Rosenbluth separation of the available world data on ⁴⁰Ca, ⁴⁸Ca, ⁵⁶Fe and ²⁰⁸Pb. We find that the Longitudinal Response Function for these nuclei is ”quenched” and that the Coulomb sum is not saturated, at odds with recent claims in the literature.