A momentum subtraction scheme for two--nucleon effective field theory

Abstract

We introduce a momentum subtraction scheme which obeys the power counting of Kaplan, Savage, and Wise (KSW), developed for systems with large scattering lengths, $a$. Unlike the power divergence subtraction scheme, coupling constants in this scheme obey the KSW scaling for all ${\mu }_R>1/a$. We comment on the low-energy theorems derived by Cohen and Hansen. We conclude that there is no obstruction to using perturbative pions for momenta $p>m_{\pi }$.

Comments: 12 pages, 3 figs