F - 13288 Marseille – Cedex 9 Electromagnetic Corrections to Low - Energy π − π Scattering †

Electromagnetic corrections to the low-energy π+π− → π0π0 scattering amplitude at next-to-leading order in the chiral expansion are reviewed. Their effects on the corresponding scattering lengths are estimated and compared to the two-loop strong interaction contributions. Key-Words: Chiral perturbation theory, Pion, Electromagnetic corrections. Contribution to the Eighth International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon, Zuoz, Engadine, Switzerland, August 15-21 1999 December 1999 CPT-99/P.3905 anonymous ftp or gopher: cpt.univ-mrs.fr ∗ Unité Propre de Recherche 7061 Work supported in part by TMR, EC-contract No. ERBFMRX-CT980169 (EURODAPHNE) 1 E-mail address: [email protected] Electromagnetic Corrections to Low-Energy ππ Scattering M. Knecht Centre de Physique Théorique, CNRS Luminy, Case 907 F-13288 Marseille Cedex 9, France Abstract Electromagnetic corrections to the low-energy ππ → ππ scattering amplitude at next-to-leading order in the chiral expansion are reviewed. Their effects on the corresponding scattering lengths are estimated and compared to the two-loop strong interaction contributions.Electromagnetic corrections to the low-energy ππ → ππ scattering amplitude at next-to-leading order in the chiral expansion are reviewed. Their effects on the corresponding scattering lengths are estimated and compared to the two-loop strong interaction contributions.