Comparison of $\bar{N}N$ optical models

Abstract

We compare the strong part of the $\bar{N}N$ interaction obtained by the Nijmegen partial wave analysis and the results of some of the most popular $\bar{N}N$ optical potentials in configuration space. We have found severe discrepancies in most of the partial waves, especially above $p_{Lab}$=400 MeV/c where the partial wave analysis displays a resonant-like structure in the ${}^{31}$S${}_0$ and ${}^{33}$P${}_0$ waves. Some theoretical difficulties to interpret this behaviour in terms of dynamical resonances are pointed pout and an alternative explanation is suggested. A much better stability is observed in the low energy parameters, apart from some discrepancies due to the presence of near-threshold quasi-bound states in particular waves. Large deviations have also been found between the corresponding potentials, at short and medium-range ($r\gtrsim 1$ fm) distances.