Nuclear Interactions of Antiprotons with Aluminium and Carbon

The development of high-energy accelerators is providing increasingly intense beams of several particles. In particular, the recent availability of negative pions and antiprotons at CERN has made it possible to study their interactions with complex nuclei. At present there exist three ways of investigating the interactions of particles such as antiprotons with complex nuclei. We refer to a) transmission experiments which measure the total interaction cross-section 1 ; b) emulsion experiments which give evidence about the "fast cascade" process in the nuclei found in nuclear emulsions 2 ; c) nuclear chemistry experiments, which measure the yields of residual nuclei. For ordinary protons as incident particles, this last method has given very detailed information on the distribution of the final products of the interaction. One important result of these investigations has been that production cross-sections for practically all residual nuclei are virtually independent of the energy of the incoming proton when this is more than about 2 GeV 3. From this one infers that the "fast cascade" initiated by the incoming proton gives a distribution of excitation energies deposited in the nucleus which is also independent of the proton energy when this is above 2 GeV.