Field theory of nucleon to higher-spin baryon transitions

Abstract

We discuss the nucleon to higher-spin N- and $\ensuremath{\Delta}$-resonance transitions by pions and photons. The higher-spin baryons are described by Rarita-Schwinger fields and, as we argue, this imposes a stringent consistency requirement on the form of the couplings. Popular $\ensuremath{\pi}N\ensuremath{\Delta}$ and $\ensuremath{\gamma}N\ensuremath{\Delta}$ couplings are inconsistent from this point of view. We construct examples of consistent interactions with the same nonrelativistic limit as the conventional ones.