A-nucleon potential

Abstract

Potentials to describe the hyperon-nucleon interaction have been calculated some time ago with the prescription of Brueckner and Watson. They treat the ∧ and Σ channels on equal footing. We have calculated from them an effective potential for the lambda-nucleon interaction that takes only implicity the effect of the closed Σ channel into account. This procedure, however, is not restricted to the hyperonnucleon case, although we only applied it there. The potentials we used were in accordance with an even ∧-Σ parity and with unitary symmetry for the pseudovector coupling constants, which they contain as parameters. It is shown that the phase shifts, resulting from the effective ∧N potential, coincide, up to about the threshold for Σ production, with the ones obtained from the original hyperon-nucleon potentials. Calculations were done both for the singlet and triplet cases. In this way, one gets an impression about the effective amounts of central, spin-orbit and tensor force in the ∧N interaction.