The Delta(1232) Resonance in Chiral Effective Field Theory

Abstract

I discuss the problem of formulating the baryon chiral perturbation theory ($\chi$PT) in the presence of a light resonance, such as the $\Delta (1232)$, the lightest nucleon resonance. It is shown how to extend the power counting of $\chi$PT to correctly account for the resonant contributions. Recent applications of the resulting chiral effective-field theory to the description of pion production reactions in $\Delta$-resonance region are briefly reviewed.

Comments: 8 pages, 8 figs; prepared for the proceedings of the Intl Erice School ``Quarks in Hadrons and Nuclei'', 29th Course, 16--24 Sep 2007, Sicily, Italy