Momentum space Faddeev calculation for N-d scattering below the breakup threshold

Abstract

Momentum space Faddeev equations for different models that also include the Coulomb force between two protons and a spin triplet nucleon-nucleon tensor force within an angular momentum approximation are solved at ${E}_{\mathrm{lab}=0.2}$ to 2.0 MeV. From a low energy expansion of the N-d S-wave phase shifts, effective range parameters are extracted. The Coulomb contribution to the relation between the trinucleon binding energy and doublet scattering length remains qualitatively unchanged when either the separable nucleon-nucleon tensor potential or the singlet potential is varied. All our doublet p-d S-wave effective range functions show a nonlinear behavior that can be ascribed to a pole connected with a virtual trinucleon bound state, whereas phase shift analysis rejects such a pole. The calculated p-d differential cross sections are roughly compatible with experiment, suggesting that phase shift analysis might not be accurate enough to detect the virtual bound state.