Applied Chiral Perturbation Theory

Abstract

I consider some selected topics in chiral perturbation theory (CHPT) as probed at colliders such as DA$\Phi$NE. Emphasis is put on processes involving pions in the isospin zero S-wave which require multi-loop calculations. These include the scalar form factor of the pion, two--photon fusion into pion pairs and $K_{\ell 4}$--decays. The physics of the chiral anomaly is briefly touched upon

Comments: 19 pp, TeX, Invited lecture, Summer School on "Hadronic Aspects of Collider Physics", Zuoz, Switzerland, August 1994. 3 figs. available upon request. CRN--94/53