Zero-Parameter Model of theN−NPotential

Abstract

We present a theoretical $N\ensuremath{-}N$ potential containing, in addition to the one-pion-exchange contribution, vector-meson-exchange terms and contributions due to the inelastic interactions $N+N\ensuremath{\rightarrow}N+\ensuremath{\Delta}(1236)$ and $N+N\ensuremath{\rightarrow}\ensuremath{\Delta}(1236)+\ensuremath{\Delta}(1236)$. There are no adjustable parameters in this calculation, which otherwise, however, suffers from most of the usual shortcomings and difficulties of few-particle-exchange models for strong-interaction processes. The vector-meson coupling constants are fixed by electromagnetic form factors and backward vector-meson production data, while the phenomenological constants in the inelastic contributions to the potentials have been fixed by the experimental data on the inelastic reactions themselves. Our results are found to be in qualitative agreement with phenomenological potentials obtained by Reid from the $N\ensuremath{-}N$ scattering data. We also calculate the vector-meson-exchange potentials for all $B\ensuremath{-}B$ and $B\ensuremath{-}\overline{B}$ states with $J\ensuremath{\le}2$. Our results indicate that the $B\ensuremath{-}B$ interaction will contain a short-range repulsion in all states of practical interest aside from the $T=1\ensuremath{\Xi}\ensuremath{-}N$ state which is discussed. We find strong attractions in most of the $\mathrm{SU}(3)$ singlet and octet $B\ensuremath{-}\overline{B}$ states.