Improved extraction of the up- and down-quark contributions to the nucleon electromagnetic form factors

Abstract

The nucleon (proton and neutron) electromagnetic form factors (FFs) are fundamental quantities in nuclear and elementary particle physics as they are essential ingredients needed to parametrize the internal structure of composite particles. The spatial distribution of charge and magnetization within the nucleon is encoded in the electric and magnetic FFs. These FFs have been extensively and precisely measured using elastic electron scattering. In addition, the combination of the proton and neutron FFs allows for the separation of the up- and down-quark contributions to the nucleon FFs. In this work, we improve on and extend to low- and high-Q2 values our original analysis and extract the up- and down-quark contributions to the nucleon electromagnetic FFs using worldwide data. In particular, we emphasize new precise data which cover the low-Q2 region which is sensitive to the large-scale structure of the nucleon. We compare our results to previous extractions and several recent theoretical calculations and models.