Report of Working Group on Electromagnetic Corrections

TL;DR

This paper reviews recent advances in calculating electromagnetic corrections to hadronic processes, including effective Lagrangians, low-energy constants, scattering amplitudes, and bound states within the Standard Model.

Contribution

It provides a comprehensive overview of methods and results for electromagnetic corrections in hadronic physics, highlighting new calculations and theoretical frameworks.

Findings

Electromagnetic corrections to K meson decays derived

Complete calculations of pi pi scattering at O(e^2p^2) presented

Theory of electromagnetic bound states of hadrons developed

Abstract

The talks delivered by M. Knecht, H. Neufeld, V.E. Lyubovitskij, A. Rusetsky and J. Soto during the session of the working group of electromagnetic corrections to hadronic processes at the Eight International Symposium MENU99, cover a wide range of problems. In particular, those include: construction of the effective Lagrangians that then are used for the evaluation of electromagnetic corrections to the decays of K mesons; evaluation of some of the low-energy constants in these Lagrangians, using sum rules and the large-N_c arguments; complete calculations of electromagnetic corrections to the pi pi scattering amplitude at O(e^2p^2); the general theory of electromagnetic bound states of hadrons in the Standard Model.