Detectability of the Negative Proton

IT is customary to employ Dirac's equation to describe the proton, which is known to have spin ½. Therefore, it is to be expected that the negative proton should exist, though this particle has never been detected experimentally. In a study of the production and annihilation of negative protons1, it was shown that it is not surprising that the particle has not been observed; but it was suggested that it could be observed, if certain cosmic ray experiments were improved. The calculations were based on the resolution of the field of a fast nucleon into a spectrum of mesons by the method of v. Weizsäcker2 and E. J. Williams3, and for simplicity account was taken only of the pseudoscalar mesons.