- th / 0 10 70 09 v 2 2 7 Ju l 2 00 1 Renormalizing the Lippmann - Schwinger equation for the one pion exchange potential

We address the question whether the cut-off dependence, which has to be introduced in order to properly define the Lippmann-Schwinger equation for the one pion exchange potential plus local (δ-function) potentials, can be removed (up to inverse powers of it) by a suitable tuning of the various (bare) coupling constants. We prove that this is indeed so both for the spin singlet and for the spin triplet channels. However, the latter requires such a strong cut-off dependence of the coupling constant associated to the non-local term which breaks orbital angular momentum conservation, that the renormalized amplitude lacks from partial wave mixing. We argue that this is an indication that this term must be treated perturbatively. PACS: 03.65.Nk, 11.10.Gh, 13.75.Cs, 21.30.Fe, 21.45.+v .