The Delta1232 Resonance in Chiral Effective Field Theory - Nuclear 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 $\Delta1232$,the lightest nucleon resonance. It is shown how to extend the power counting of$\chi$PT to correctly account for the resonant contributions. Recentapplications of the resulting chiral effective-field theory to the descriptionof pion production reactions in $\Delta$-resonance region are briefly reviewed.