Cosmic ray antiprotons 5-12 GeV

The authors have reevaluated calculations of the flux to be expected assuming that antiprotons are due to collisions of cosmic rays with interstellar matter. They find that the reported result, anti p/p approximately (5.2 +- 1.5) x 10-4, is 3-4 times greater than would be expected if cosmic ray protons sample the same distribution of interstellar matter seen by nuclei with Z > 1. This conclusion differs from that reached by Golden et al. because they used an earlier calculation by Badhwar et al. (1975) which gave a anti p/p ratio significantly higher than the original estimate of Gaisser and Maurer (1973). (Auth.)