Measurements of the antiproton-proton annihilation cross-section in the beam momentum range between 180 and 600 MeV/c

The antiproton-proton annihilation cross-section has been mesasured for antiproton beam momenta between 180 and 600 MeV/c. The annihilation cross-section is found to be larger than the geometrical limit of thes-wave inelastic cross-section in this momentum range, indicating a significantp-wave contribution even at low momenta.