REGULARIZATION METHODS FOR NUCLEON-NUCLEON EFFECTIVE-FIELD THEORY

Attempts to apply effective field theory (EFT) methods to nonrelativis tic nucleon-nucleon (NN) scattering have raised questions about the na ture and limitations of an EFT expansion when used nonperturbatively. We discuss the characteristics of a meaningful EFT analysis and compar e them with traditional approaches to NN scattering. A key feature of an EFT treatment is a systematic expansion in powers of momentum, whic h we demonstrate using an error analysis introduced by Lepage. A clear graphical determination of the radius of convergence for the momentum expansion is also obtained. We use these techniques to compare cutoff regularization, two forms of dimensional regularization, and the diba ryon approach, using a simple model for illustration. The naturalness of the parameters and predictions for bound-state energies are also sh own. (C) 1998 Elsevier Science B.V.