The features and problems of a speculative model based on the electron neutrino being a tachyon are discussed. The model is consistent with five properties of the cosmic ray spectrum, and it predicts a flux of neutrons in a narrow energy region centered on $4.5\pm 2.2\times {10}^{15}$ eV.

• Received 10 September 1998

DOI:https://doi.org/10.1103/PhysRevD.60.017302