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 (14)

• 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
• Nucleon electromagnetic form factors
• Two-Photon Physics in Hadronic Processes
• 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)
• 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 neutron negative central charge density: an inclusive-exclusive connection