Electromagnetic form factors of the nucleon: new fit and analysis of uncertainties

TL;DR

This paper presents a new fit of electromagnetic form factors for protons and neutrons, incorporating two-photon exchange corrections and analyzing uncertainties and correlations within the data.

Contribution

It introduces a comprehensive fit of nucleon form factors using recent data and accounts for two-photon exchange effects, providing detailed uncertainty analysis.

Findings

Proton form factors fitted in the Q^2 range 0-6 GeV^2.

Uncertainties and correlations of form factors thoroughly analyzed.

Inclusion of two-photon exchange corrections improves fit accuracy.

Abstract

Electromagnetic form factors of proton and neutron, obtained from a new fit of data, are presented. The proton form factors are obtained from a simultaneous fit to the ratio $\mu_p G_{Ep}/G_{Mp}$ determined from polarization transfer measurements and to $ep$ elastic cross section data. Phenomenological two-photon exchange corrections are taken into account. The present fit for proton was performed in the kinematical region $Q^2\in (0,6)$ GeV$^2$. Both for protons and neutrons we use the latest available data. For all form factors the uncertainties and correlations of form factor parameters are investigated with the $\chi^2$ method.