Narrow resonances in effective field theory

We discuss the power counting for effective field theories with narrow resonances near a two-body threshold. Close to threshold, the effective field theory is perturbative and only one combination of coupling constants is fine-tuned. In the vicinity of the resonance, a second, “kinematic” fine-tuning requires a nonperturbative resummation. We illustrate our results in the case of nucleon-alpha scattering.