Comparison of results for the electromagnetic form factors of the proton at low $Q^2$

Abstract

The goal in this work is the comparison of five parameterisations of the Sachs form factors of the proton $G_E^p$ (electric) and $G_M^p$ (magnetic) at low $4$-momentum transfer $Q^2$. It will be shown that a simple model, based on two dipoles which admit as parameters the rms electric charge radius $r_{E;p}$ and the rms magnetic radius $r_{M;p}$ of the proton, suffices for the purposes of the phase-shift analyses (PSAs) of the low-energy pion-nucleon ($\pi N$) data. The replacement of the electromagnetic form factors, currently used in the ETH model of the $\pi N$ interaction, by the parameterisation of this work will enable the removal from the PSAs of this research programme of the largest part of the dependence on extraneous sources.

20 pages, 4 figures, 1 table

References in corpus (9)

• Global analysis of proton elastic form factor data with two-photon exchange corrections
• Dispersion analysis of the nucleon form factors including meson continua
• Proton and neutron electromagnetic form factors and uncertainties
• Realistic Transverse Images of the Proton Charge and Magnetic Densities
• Model independent extraction of the proton magnetic radius from electron scattering
• Proton root-mean-square radii and electron scattering
• Proton radius from electron-proton scattering and chiral perturbation theory
• Determination of the masses and decay widths of the scalar-isoscalar and vector-isovector mesons below $2$ GeV
• Determination of the masses and decay widths of the well-established $s$ and $p$ baryon resonances below $2$ GeV