https://doi.org/10.1140/epja/i2006-09-007-4
MAMI 2005
Chiral perturbation theory
Success and challenge
Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, J.J. Becher Weg 45, D-55099, Mainz, Germany
* e-mail: scherer@kph.uni-mainz.de
Received:
11
May
2006
Accepted:
11
May
2006
Published online:
12
May
2006
Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic polarizabilities of the pion. These have recently been extracted from an experiment on radiative π+ photoproduction from the proton ( γp → γπ+ n) at the Mainz Microtron MAMI. Next we will turn to the one-baryon sector of chiral perturbation theory and will address the issue of a consistent power counting scheme. As examples of the heavy-baryon framework we will comment on the extraction of the axial radius from pion electroproduction and will discuss the generalized polarizabilities of the proton. Finally, we will discuss two recently proposed manifestly Lorentz-invariant renormalization schemes and illustrate their application in a calculation of the nucleon electromagnetic form factors.
PACS: 11.10.Gh Renormalization – / 11.30.Rd Chiral symmetries – / 13.40.-f Electromagnetic processes and properties – / 13.40.Gp Electromagnetic form factors – / 13.60.Fz Elastic and Compton scattering – / 13.60.Le Meson production –
© Società Italiana di Fisica and Springer-Verlag, 2006
