Limits on the low-energy antinucleon-nucleus annihilations from the Heisenberg principle

We show that the quantum uncertainty principle puts some limits on the effectiveness of the antinucleon-nucleus annihilation at very low energies. This is caused by the fact that a very effective short-distance reaction process implies information on the relative distance of the reacting particles. Some quantitative predictions are possible on this ground, including the approximate A-independence of $\bar{N}$-nucleus annihilation rates