Pion Electroproduction Amplitude Relations in the 1/N_c Expansion
High Energy Physics - Phenomenology
2009-10-29 v2
Abstract
We derive expressions for pion electroproduction amplitudes in the 1/N_c expansion of QCD, and obtain from them linear relations between the electromagnetic multipole amplitudes that hold at all energies. The leading-order relations in 1/N_c compare favorably with available data (especially away from resonances), but the next-to-leading-order relations tend to provide only small or no improvement.
Cite
@article{arxiv.0905.0122,
title = {Pion Electroproduction Amplitude Relations in the 1/N_c Expansion},
author = {Richard F. Lebed and Lang Yu},
journal= {arXiv preprint arXiv:0905.0122},
year = {2009}
}
Comments
45 pages, pdflatex, contains multiple figures but .pdf file is < 4 MB. This version to appear in Phys. Rev. D, but has much better figure resolution. References greatly expanded, some additional discussion