Nucleon Form Factors - A Jefferson Lab Perspective

Abstract

The charge and magnetization distributions of the proton and neutron are encoded in their elastic electromagnetic form factors, which can be measured in elastic electron--nucleon scattering. By measuring the form factors, we probe the spatial distribution of the proton charge and magnetization, providing the most direct connection to the spatial distribution of quarks inside the proton. For decades, the form factors were probed through measurements of unpolarized elastic electron scattering, but by the 1980s, progress slowed dramatically due to the intrinsic limitations of the unpolarized measurements. Early measurements at several laboratories demonstrated the feasibility and power of measurements using polarization degrees of freedom to probe the spatial structure of the nucleon. A program of polarization measurements at Jefferson Lab led to a renaissance in the field of study, and significant new insight into the structure of matter.

20 pages, 9 figures; Chapter in the book "A decade of Physics at Jefferson Lab", to be published in Journal of Physics: Conference Series

References in corpus (20)

• High-precision determination of the electric and magnetic form factors of the proton
• Nucleon Electromagnetic Form Factors
• Global analysis of proton elastic form factor data with two-photon exchange corrections
• Charge Density of the Neutron
• Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2
• Nucleon electromagnetic form factors
• Two-Photon Physics in Hadronic Processes
• Survey of nucleon electromagnetic form factors
• Measurements of the Electric Form Factor of the Neutron up to Q2=3.4 GeV2 using the Reaction He3(e,e'n)pp
• Measurement of the proton electric to magnetic form factor ratio from \vec ^1H(\vec e, e'p)
• Polarization Transfer in the 4He(e,e'p)3H Reaction at Q^2 = 0.8 and 1.3 (GeV/c)^2
• A Precise Measurement of the Neutron Magnetic Form Factor GMn in the Few-GeV2 Region
• Realistic Transverse Images of the Proton Charge and Magnetic Densities
• Updated dispersion-theoretical analysis of the nucleon electromagnetic form factors
• The Charge Form Factor of the Neutron at Low Momentum Transfer from the ${}^2\vec{\mathrm{H}}(\vec{\mathrm{e}},{\mathrm{e}}^{\prime }\mathrm{n})\mathrm{p}$ Reaction
• The structure function method applied to polarized and unpolarized electron-proton scattering: a solution of the G_E(p)/G_M(p) discrepancy
• Extraction of the Neutron Magnetic Form Factor from Quasi-Elastic 3He(pol)(e(pol),e') at Q^2 = 0.1 - 0.6 (GeV/c)^2
• Contribution of spin 1/2 and 3/2 resonances to two-photon exchange effects in elastic electron-proton scattering
• The Proton Elastic Form Factor Ratio at Low Momentum Transfer
• The neutron negative central charge density: an inclusive-exclusive connection

Cited by in corpus (25)

• Baryons as relativistic three-quark bound states
• Muonic hydrogen and the proton radius puzzle
• High Precision Measurement of the Proton Elastic Form Factor Ratio ${\mu }_p{G}_E/G_M$ at low $Q^2$
• Review of two-photon exchange in electron scattering
• Proton and neutron electromagnetic form factors and uncertainties
• Low Q^2 measurements of the proton form factor ratio $m{u}_p{G}_E/G_M$
• Towards a resolution of the proton form factor problem: new electron and positron scattering data
• Polarization Transfer Observables in Elastic Electron Proton Scattering at $Q^2=$2.5, 5.2, 6.8, and 8.5 GeV${}^2$
• New insights into the nucleon's electromagnetic structure
• Nucleon Electromagnetic Form Factors in the Timelike Region
• Flavor decomposition of the nucleon electromagnetic form factors
• Nucleon form factors and spin content in a quark-diquark model with a pion cloud
• Dirac and Pauli form factors from lattice QCD
• Magnetic and quadrupole moments of the $Z_c(3900)$
• Chiral extrapolations for nucleon electric charge radii
• Chiral extrapolations for nucleon magnetic moments
• Demonstration of a novel technique to measure two-photon exchange effects in elastic $e^{\pm }p$ scattering
• Polarization of the final nucleon in quasi-elastic neutrino scattering and the axial form factor of the nucleon
• On the polarization of the final nucleon in NC elastic ν_μ(\barν_μ) - N scattering
• Up- and down-quark contributions to the nucleon electromagnetic form factors at low $Q^2$
• Proton and neutron form factors from deformed gravity/gauge duality
• Polarized Lepton-Nucleon Elastic Scattering and a Search for a Light Scalar Boson
• A measurement of two-photon exchange in Super-Rosenbluth separations with positron beams
• Baryon Form Factors
• A novel measurement of the neutron magnetic form factor from A=3 mirror nuclei