arXiv:hep-ph/9409442·v2·High Energy Physics — Phenomenology
What is a low-energy theorem ?
G. Ecker🇦🇹 · U.-G. Meissner🇫🇷
Abstract
We discuss the meaning of low-energy theorems (LETs) in the framework of the effective field theory of the standard model. Particular emphasis is put on the LET for neutral pion photoproduction off nucleons at threshold. The seemingly controversial situation surrounding this LET is clarified.
Comments: 17 pp., Latex, 2 figures included, CRN-94/52, UWThPh-1994-33, submitted to Comments Nucl. Part. Phys. (no changes at all, but by request of the E-print Admin. the figures are now in a uuencoded, compressed postscript file)