Neutron charge radius and the Dirac equation

Abstract

We consider the Dirac equation for a finite-size neutron in an external electric field. We explicitly incorporate Dirac-Pauli form factors into the Dirac equation. After a non-relativistic reduction, the Darwin-Foldy term is cancelled by a contribution from the Dirac form factor, so that the only coefficient of the external field charge density is $e/6r_{En}^2$, i. e. the root mean square radius associated with the electric Sachs form factor . Our result is similar to a recent result of Isgur, and reconciles two apparently conflicting viewpoints about the use of the Dirac equation for the description of nucleons.

7 pages, no figures, to appear in Physical Review C

References in corpus (2)

• Interpreting the Neutron's Electric Form Factor: Rest Frame Charge Distribution or Foldy Term?
• Pionic Fluctuations of Constituent Quarks

Cited by in corpus (4)

• Muonic hydrogen and the proton radius puzzle
• Nucleon Charge and Magnetization Densities from Sachs Form Factors
• LHC Searches for Dark Sector Showers
• Detecting Nanometer-Scale New Forces with Coherent Neutron Scattering