What Do We Know About the Strange Magnetic Radius?
Abstract
We analyze the q^2-dependence of the strange magnetic form factor, \GMS(q^2), using heavy baryon chiral perturbation theory (HBChPT) and dispersion relations. We find that in HBChPT a significant cancellation occurs between the O(p^2) and O(p^3) loop contributions. Consequently, the slope of \GMS at the origin displays an enhanced sensitivity to an unknown O(p^3) low-energy constant. Using dispersion theory, we estimate the magnitude of this constant, show that it may have a natural size, and conclude that the low-q^2 behavior of \GMS could be dominated by nonperturbative physics. We also discuss the implications for the interpretation of parity-violating electron scattering measurements used to measure \GMS(q^2).
Cite
@article{arxiv.hep-ph/0206301,
title = {What Do We Know About the Strange Magnetic Radius?},
author = {H. -W. Hammer and S. J. Puglia and M. J. Ramsey-Musolf and Shi-Lin Zhu},
journal= {arXiv preprint arXiv:hep-ph/0206301},
year = {2009}
}
Comments
9 pages, Revtex, 2 ps figures