The antinucleon‐nucleon system at non‐relativistic energies

We first point out the connection between NN and N?. This connection implies many bound and resonant states with widths which are very sensitive to the details of the nucleon core. Reasonable core boundary conditions may produce in principle very narrow (certainly much smaller than the unobstructive widths which are ?mπ) high spin states. We shall then discuss experimental results which directly or indirectly favor the existence of narrow N? bound and resonant states.