M. Knecht1 - H. Neufeld2 - H. Rupertsberger2 - P. Talavera3
1 Centre de Physique Théorique, CNRS Luminy,
Case 907, 13288 Marseille Cedex 9, France
2 Institut für Theoretische Physik, Universität Wien, Boltzmanngasse 5, 1090 Wien, Austria
3 Department of Theoretical Physics 2, Lund University, Sölvegatan 14A, 22362 Lund, Sweden
Received: 9 September 1999 / Published online: 10 December 1999
We construct a low-energy effective field theory which allows for a full treatment of the isospin-breaking effects in semileptonic weak interactions. To this end, we enlarge the particle spectrum of chiral perturbation theory with virtual photons by including also the light leptons as dynamical degrees of freedom. Using super-heat-kernel techniques, we determine the additional one-loop divergences generated by the presence of virtual leptons and give the full list of associated local counterterms. We illustrate the use of our effective theory by applying it to the decays and .
Copyright Springer-Verlag 2000