Proton Electromagnetic Form Factor Ratios at Low Q^2

Abstract

We study the ratio $R\equiv \mu G_E(Q^2)/G_M(Q^2)$ of the proton at very small values of $Q^2$. Radii commonly associated with these form factors are not moments of charge or magnetization densities. We show that the form factor $F_2$ is correctly interpretable as the two-dimensional Fourier transformation of a magnetization density. A relationship between the measurable ratio and moments of true charge and magnetization densities is derived. We find that existing measurements show that the magnetization density extends further than the charge density, in contrast with expectations based on the measured reduction of $R$ as $Q^2$ increases.

4 pages 3 figures We have corrected references, figures and some typographical errors

References in corpus (27)

• Wave Functions, Evolution Equations and Evolution Kernels from Light-Ray Operators of QCD
• Nonforward Parton Distributions
• Impact Parameter Space Interpretation for Generalized Parton Distributions
• Off-Forward Parton Distributions
• Nucleon Electromagnetic Form Factors
• Generalized parton distributions in impact parameter space
• Global analysis of proton elastic form factor data with two-photon exchange corrections
• Charge Density of the Neutron
• Dispersion analysis of the nucleon form factors including meson continua
• Nucleon electromagnetic form factors
• A Coherent Interpretation of the Form Factors of the Nucleon in Terms of a Pion Cloud and Constituent Quarks
• Electromagnetic Form Factors of the Nucleon and Compton Scattering
• Light Front Cloudy Bag Model: Nucleon Electromagnetic Form Factors
• Transverse Deformation of Parton Distributions and Transversity Decomposition of Angular Momentum
• Impact Parameter Dependent Parton Distributions and Transverse Single Spin Asymmetries
• Implications of the discrepancy between proton form factor measurements
• Empirical transverse charge densities in the nucleon and the nucleon-to-$\Delta$ transition
• Measurement of the proton electric to magnetic form factor ratio from \vec ^1H(\vec e, e'p)
• The Role of Color Neutrality in Nuclear Physics--Modifications of Nucleonic Wave Functions
• Status on nucleon electromagnetic form factors
• SU(6) breaking effects in the nucleon elastic electromagnetic form factors
• Precise determination of low-Q nucleon electromagnetic form factors and their impact on parity-violating e-p elastic scattering
• Zemach and magnetic radius of the proton from the hyperfine splitting in hydrogen
• Electroweak structure of the nucleon, meson cloud and light-cone wavefunctions
• Nucleon form factors and a nonpointlike diquark
• The Proton Elastic Form Factor Ratio at Low Momentum Transfer
• On the pion cloud of the nucleon

Cited by in corpus (26)

• Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2
• Final Analysis of Proton Form Factor Ratio Data at ${\mathbf{Q}}^2=4.0$, 4.8 and 5.6 GeV${}^2$
• Transverse Charge Densities
• Nucleon electromagnetic form factors from the covariant Faddeev equation
• Low Q^2 measurements of the proton form factor ratio $m{u}_p{G}_E/G_M$
• Realistic Transverse Images of the Proton Charge and Magnetic Densities
• Electromagnetic Form Factors and Charge Densities From Hadrons to Nuclei
• Empirical transverse charge densities in the deuteron
• Neutron Properties in the Medium
• The Role of Mesons in the Electromagnetic Form Factors of the Nucleon
• Hadron and light nucleus radii from electron scattering
• On the definition of electromagnetic local spatial densities for composite spin-$1/2$ systems
• The neutron negative central charge density: an inclusive-exclusive connection
• Novel twist-three transverse-spin sum rule for the proton and related generalized parton distributions
• Nucleon relativistic polarization and magnetization distributions
• Charge and magnetization densities in transverse coordinate and impact parameter space
• Transverse charge density and the radius of the proton
• Pauli radius of the proton
• Transverse densities and generalized parton distributions of $\rho$ meson in light front quark model
• Transverse charge densities of the deuteron in soft-wall AdS/QCD
• Neutrino propagation in the neutron star with uncertainties from nuclear, hadron, and particle physics
• Timelike Virtual Compton Scattering from Electron-Positron Radiative Annihilation
• A concept for the experimental determination of the nucleon electric to magnetic form factor ratio at very low $Q^2$
• The Inclusive-Exclusive Connection and the Neutron Negative Central Charge Density
• Model independent results for nucleon structure
• Unpolarized nucleon structure studies utilizing polarized electromagnetic probes