Energy of a point-like neutron in an external electromagnetic field
Abstract
A point-like neutron in an external electromagnetic field experiences a shift in energy that mimicks the effect of an actual structural deformation of an extended neutron, i.e., a proper polarizability. In order to be able to differentiate between the former and the latter, a Foldy-Wouthuysen transformation is constructed which yields the energy shift of a point-like neutron quadratic in the external field in a derivative expansion, generalizing a long-known result for the dipole electric polarizability due to Foldy. The ten leading Foldy contributions to the energy are determined for a zero-momentum neutron. In addition, eliminating the momentum operator in favor of the velocity operator, analogous results are derived for a zero-velocity neutron. In this case, operator ordering ambiguities are encountered that permit only a determination of eight of the ten Foldy terms.
Keywords
Cite
@article{arxiv.2008.10691,
title = {Energy of a point-like neutron in an external electromagnetic field},
author = {Jesus Saenz and Michael Engelhardt and Roman Höllwieser},
journal= {arXiv preprint arXiv:2008.10691},
year = {2021}
}
Comments
Version accepted for publication