Journal ArticleDOI
The Electromagnetic Properties of Dirac Particles
TLDR
In this paper, a framework for describing the electromagnetic properties of Dirac (spin-textonehalf{}) particles which determine their behavior when moving with low momentum through weak, slowly varying, external electromagnetic fields is developed by finding the most general interaction terms which may be added to the Dirac equation for the particle subject to appropriate conditions.Abstract:
A framework for describing those electromagnetic properties of Dirac (spin-\textonehalf{}) particles which determine their behavior when moving with low momentum through weak, slowly varying, external electromagnetic fields is developed by finding the most general interaction terms which may be added to the Dirac equation for the particle subject to appropriate conditions. The interaction terms found form an infinite series involving arbitrarily high derivatives of the electromagnetic potentials evaluated at the position of the particle. The series of coefficients of these terms then characterize the properties to be described and can be interpreted as a series of moments of the charge and current distribution associated with the Dirac particle. The first coefficient represents the charge of the particle, the second its anomalous magnetic moment. The third is a measure of the spatial extent of the particle's charge distribution, and the corresponding term describes a direct interaction of the particle and the charge distribution responsible for the external electromagnetic field. Higher terms in the series describe direct interactions of the particle with various derivatives of the external charge and current distribution. The correct physical interpretation of the terms is examined by transforming to the Foldy-Wouthuysen (nonrelativistic) representation of the Dirac equation. The consistency of the framework developed with field theoretical results is discussed. Limitations of the characterization derived here and the possibilities of broadening the assumptions on which it is based are examined. The results are applied in the succeeding paper to the interpretation of the electromagnetic properties of nucleons with particular reference to the electron-neutron interaction.read more
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Journal ArticleDOI
Studies in perturbation theory . Part I. An elementary iteration-variation procedure for solving the Schrödinger equation by partitioning technique
Per-Olov Löwdin,Per-Olov Löwdin +1 more
TL;DR: In this paper, the Schrodinger equation in quantum mechanics is transformed to a discrete representation by introducing a complete set of basis functions in which the eigenfunctions may be developed by solving a secular equation, and this problem is here attacked by a partitioning which leads to an implicit relation for the energy E of the form E = f (E ), which corresponds to the Schodoringer-Brillouin perturbation formula but has a more condensed form.
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TL;DR: In this article, the authors review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates.
Journal ArticleDOI
Electromagnetic effects in the quantum interference of dipoles
Jeeva Anandan,Jeeva Anandan +1 more
TL;DR: In this paper, the phase shift in the interference of a magnetic or electric dipole due to the electromagnetic field is obtained relativistically and non-relativistically, and the force and torque on the particle are obtained in the classical limit.
Journal ArticleDOI
The Foldy-Wouthuysen transformation
TL;DR: The Foldy-Wouthuysen transformation of the Dirac Hamiltonian is generally taught as simply a mathematical trick that allows one to obtain a two-component theory in the low energy limit as mentioned in this paper.
Journal ArticleDOI
New measurement of the charge radius of the neutron.
TL;DR: Analyzing the shape of the transmission spectra as a function of neutron energy, agreement was found with the predictions by the atomic form factor.