Pion-nucleon scattering and isospin violation

Abstract

I discuss low-energy pion-nucleon scattering in the framework of chiral perturbation theory. I argue that using this theoretical method one is able to handle the in some cases tremendous experimental accuracy (for the low partial waves). I then show how strong and electromagnetic isospin violation can be treated simultaneously. Some first results for neutral pion scattering and the $σ$-term are given.

9 pp, LaTeX, uses psfig and sprocl.sty, 3 figs, invited talk, workshop on "Future Directions in Quark-Nuclear Physics", Adelaide, March 1998