Calculations on the three-nucleon system using a separable expansion of local potentials

Abstract

Abstract A separable expansion for local potentials called the unitary pole expansion (UPE) has been applied to the singlet-S soft-core Reid potential. The separable potentials obtained are used in conjunction with a separable tensor potential to calculate the triton binding energy, the nd doublet scattering length and the nd phase shifts in the 1 2 + state above and below break up. The convergence of the UPE is good especially for repulsive terms. The one term approximation (UPA) gives a triton energy differing by 0.04 MeV and a doublet scattering length differing by 0.14 fm from the values found for the local potential. The calculated phase shifts are in good agreement with the phase-shift analysis of Van Oers and Seagrave.