pi pi scattering, pion form factors and chiral perturbation theory

Abstract

I discuss recent progress in our understanding of the pi pi scattering amplitude at low energy thanks to the combined use of chiral perturbation theory and dispersion relations. I also comment on the criticism raised by Pelaez and Yndurain on this work.

Comments: 10 pages, 5 figures. Invited talk at the "Quark Confinement and the Hadron Spectrum" VI Conference, Villasimius, Sardinia, Italy, 21-25 September 2004