Pion photo- and electroproduction and the chiral MAID interface

TL;DR

This paper presents a Lorentz-invariant baryon chiral perturbation theory calculation of pion photo- and electroproduction up to order $q^4$, with results accessible through the chiral MAID web interface.

Contribution

It introduces an extended on-mass-shell scheme for baryon chiral perturbation theory and provides a computational tool for analyzing pion production data.

Findings

Calculated pion photo- and electroproduction cross sections up to order $q^4$

Fitted low-energy constants to experimental data across channels

Developed a web interface for accessing and analyzing results

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/). We explain how our program works and how it can be used for further analysis.