Antiproton annihilation on deuteron and bound states in the nucleon--antinucleon system

The momentum distributions of the recoil nucleon (spectator) in the reaction p̄+d→n+(NN̄) have been calculated taking into account the possible levels in the NN̄ system. The comparison of the theory with the experimental data on p annihilation at rest shows the existence of a p̄n bound D state with quantum numbers $J^{PG}=1^{-+}$.