The Electromagnetic Interaction in Chiral Perturbation Theory

Abstract

We investigate electromagnetic effects in the framework of chiral perturbation theory. Using a completely independent method, we confirm Urech's results for the divergences of the one--loop functional in the electromagnetic sector. We perform a one--loop analysis of all $P_{\ell 2}$ ($P=\pi ,K,\eta$) and the $K_{\ell 3}$ form factors $f_{+}^{K^{+}{\pi }^0}(0)$, $f_{+}^{K^0{\pi }^{-}}(0)$, including a systematic treatment of the $\text{cO}(e^2{p}^2)$ contributions in the mesonic part. We illustrate our results by several numerical estimates.

Comments: 15 pages, latex