Cosmic-ray antimatter

We examine the possibility that the observed cosmic-ray protons are of primary extragalactic origin. The present anti p data are consistent with a primary extragalactic component having anti p/papprox.=3.2+-0.7x10-4 independent of energy. Following the suggestion that most extragalactic cosmic rays are from active galaxies, we propose that most of the observed anti p's are also from the same sites. This would imply the possibility of destroying the corresponding anti α's at the source, thus leading to a flux ratio anti α/α< anti p/p. We further predict an estimate for anti α/αproportional10-5, within the range of future cosmic-ray detectors. The cosmological implications of this proposal are discussed. (orig.)