Measurement of the antineutron-proton cross section at low energy

The total and annihilation cross sections of antineutrons on protons and carbon nuclei have been measured for antineutron momenta 0.25 to 0.88 GeV/c using a novel poor-geometry transmission technique. The measured cross sections are similar to antiproton cross sections in the same energy region. The presence of higher angular momenta ($\ge P$ wave) in the annihilation is confirmed down to 0.25 GeV/c. The Glauber-Wilkin correction to the $\overline{p}d$ total cross section is verified to 20% precision in this momentum region.