The pion-nucleon interaction as an effective field theory

Abstract

After a brief survey of effective field theories, the linear sigma model is discussed as a prototype of an effective field theory of the standard model below the chiral-symmetry-breaking scale. Although it can serve as a toy model for the pion-nucleon interaction, the linear sigma model is not a realistic alternative to chiral perturbation theory. The heavy-baryon approach to chiral perturbation theory allows for a systematic low-energy expansion of Green functions and amplitudes with baryons. The chiral-invariant renormalization of the effective field theory for the pion-nucleon system to O(p^3) in the chiral expansion is reviewed.

Comments: 11 pages, Latex, 2 figures in uuencoded, compressed postscript file, Univ. Wien preprint UWThPh-1994-24, to appear in Proc. of First International Symposium on Symmetries in Subatomic Physics, Taipei, Taiwan, May 1994