arXiv:nucl-th/0304007·v1·Nuclear Theory
Narrow Resonances in Effective Field Theory
P.F. Bedaque (LBNL)🇺🇸 · H.-W. Hammer (Bonn U.)🇩🇪 · U. van Kolck (U. of Arizona and RIKEN-BNL)🇺🇸
Abstract
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.
Comments: 11 pages, revtex4, 3 ps figures