The Proton Elastic Form Factor Ratio at Low Momentum Transfer

Abstract

High precision measurements of the proton elastic form factor ratio have been made at four-momentum transfers, Q^2, between 0.2 and 0.5 GeV^2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q^2 range the deviation from unity is primarily due to GEp being smaller than the dipole parameterization.

5 pages, 2 figures

References in corpus (10)

• Nucleon Electromagnetic Form Factors
• Dispersion analysis of the nucleon form factors including meson continua
• Nucleon electromagnetic form factors
• Precision Measurements of the Nucleon Strange Form Factors at Q^2 ~0.1 GeV^2
• Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering
• Measurement of the proton electric to magnetic form factor ratio from \vec ^1H(\vec e, e'p)
• Proton G_E/G_M from beam-target asymmetry
• Precise determination of low-Q nucleon electromagnetic form factors and their impact on parity-violating e-p elastic scattering
• Polarization transfer in the d(epol,e' ppol)n reaction up to Q^2=1.61 (GeV/c)^2
• New experimental constraints on polarizability corrections to hydrogen hyperfine structure

Cited by in corpus (30)

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• Review of two-photon exchange in electron scattering
• Final Analysis of Proton Form Factor Ratio Data at ${\mathbf{Q}}^2=4.0$, 4.8 and 5.6 GeV${}^2$
• Extraction of the proton radius from electron-proton scattering data
• Nucleon form factors, generalized parton distributions and quark angular momentum
• Two-photon exchange in elastic electron-proton scattering
• Polarization Transfer in the 4He(e,e'p)3H Reaction at Q^2 = 0.8 and 1.3 (GeV/c)^2
• Low Q^2 measurements of the proton form factor ratio $m{u}_p{G}_E/G_M$
• Polarization Transfer Observables in Elastic Electron Proton Scattering at $Q^2=$2.5, 5.2, 6.8, and 8.5 GeV${}^2$
• Electromagnetic form factors of the nucleon: new fit and analysis of uncertainties
• Are Electron Scattering Data Consistent with a Small Proton Radius?
• Flavor decomposition of the nucleon electromagnetic form factors
• Nucleon Form Factors - A Jefferson Lab Perspective
• Neutron Properties in the Medium
• The Role of Mesons in the Electromagnetic Form Factors of the Nucleon
• Proton Electromagnetic Form Factor Ratios at Low Q^2
• Charge radii of the nucleon from its flavor dependent Dirac form factors
• Ejectile Polarization for ${}^{2}H(e,e^{\prime }\vec{p})n$ at GeV energies
• Proton Form Factor Ratio, ${\mu }_p{G}_E^p/G_M^p$ from Double Spin Asymmetry
• Study of the in-medium nucleon electromagnetic form factors using a light-front nucleon wave function combined with the quark-meson coupling model
• Overview and Perspectives in Nuclear Physics
• Proton Polarimeter Calibration between 82 and 217 MeV
• Electromagnetic Form Factors of Nucleons with QCD Constraints Sytematic Study of the Space and Time-like Regions
• Polarization Observables in Deuteron Photodisintegration below 360 MeV
• Quantized form factor shift in the presence of free electron laser radiation
• Unpolarized nucleon structure studies utilizing polarized electromagnetic probes
• Two-photon contributions to the Rosenbluth cross-section in the Skyrme model