Local gauge invariance implies Siegert's hypothesis
Nuclear Theory
2008-11-26 v1
Abstract
The nonrelativistic Ward-Takahashi identity, a consequence of local gauge invariance in quantum mechanics, shows the necessity of exchange current contributions in case of nonlocal and/or isospin-dependent potentials. It also implies Siegert's hypothesis: in the nonrelativistic limit, two-body charge densities identically vanish. Neither current conservation, which follows from global gauge invariance, nor the constraints of (lowest order) relativity are sufficient to arrive at this result. Furthermore, a low-energy theorem for exchange contributions is established.
Cite
@article{arxiv.nucl-th/9608063,
title = {Local gauge invariance implies Siegert's hypothesis},
author = {H. W. L. Naus},
journal= {arXiv preprint arXiv:nucl-th/9608063},
year = {2008}
}
Comments
5 pages, REVTEX