The status of our present knowledge on the antinucleon-nucleon interaction at
low and medium energies is discussed. Special emphasis is put on aspects
related to its spin dependence which are relevant for experiments planned by
the PAX collaboration. Predictions for the spin-dependent antiproton-proton
cross sections sigma_1 and sigma_2 are presented, utilizing antinucleon-nucleon
potential models developed by the Juelich group, and compared to results based
on the amplitudes of the Nijmegen partial-wave analysis.Comment: 8 pages, 4 figures, to appear in the proceedings of the 19th
International Spin Physics Symposium, September 27 - October 2, 2010,
Juelich, German
