Pion photo- and electroproduction and the partially-conserved axial current
Abstract
The relevance of the axial current for pion production processes off the nucleon with real or virtual photons is revisited. Employing the hypothesis of a partially conserved axial current (PCAC), it is shown that, when all of the relevant contributions are taken into account, PCAC does not provide any additional constraint for threshold production processes that goes beyond the Goldberger-Treiman relation. In particular, it is shown that pion electroproduction processes at threshold cannot be used to extract any information regarding the weak axial form factor. The relationships found in previous investigations are seen to be an accident of the approximations usually made in this context.
Keywords
Cite
@article{arxiv.nucl-th/0005016,
title = {Pion photo- and electroproduction and the partially-conserved axial current},
author = {Helmut Haberzettl},
journal= {arXiv preprint arXiv:nucl-th/0005016},
year = {2009}
}
Comments
4 pages, 3 figures; typos corrected; references updated; some rewording; conclusions unchanged