Renormalization of ${}^1{S}_0$ NN scattering amplitude in effective field theory

Cutoff regularized subleading order ${}^1{S}_0$ NN potential of effective field theory (EFT) is iterated using Lippmann-Schwinger equation. It is shown that the scattering amplitudes calculated in cutoff and subtractively renormalized EFT are equal up to the accuracy of performed calculations. Non-perturbative renormalization, where part of divergences are absorbed into two contact interaction coupling constants with subsequent removal of regularization is also performed. Cutoff and dimensional regularizations both lead to finite but different results within this scheme.