Pion Photo- and Electroproduction and the Chiral MAID Interface

Abstract

We discuss the extended on-mass-shell scheme for manifestly Lorentz-invariant baryon chiral perturbation theory. We present a calculation of pion photo- and electroproduction up to and including order $q^4$. The low-energy constants have been fixed by fitting experimental data in all available reaction channels. Our results can be accessed via a web interface, the so-called chiral MAID (http://www.kph.uni-mainz.de/MAID/chiralmaid/).

Comments: 11 pages, 7 figures, invited talk given by S. Scherer at NSTAR 2015, May 25-28, 2015, Osaka, Japan