Report on results on anti np total cross section and anti pp charge exchange differential cross section

Two experiments are reported through which one attempts to circumvent the problem of rapid energy loss for the anti p which causes difficulty in accurately assessing the anti p momentum. For this purpose the anti np cross section is measured, also anti pp charge exchange differential cross sections and an anti np total cross section. The momentum range of 200 to 1000 MeV/c is covered. It is found that while the anti np total cross section rises at low momentum, the effect is not as strong as has been seen in anti pp. It is not clear if this is due to the problem of measuring very low anti p momenta, but there is other evidence to indicate a possible low lying resonance in anti pp