Abstract
The variation of the hard cosmic-ray component with zenith angle and the temperature effect suggest that the cosmic mesotrons decay with a lifetime of about 3 × sec. The other phenomena so far considered (variation with height, barometer effect, shape of the energy spectrum, number of secondaries, etc.) do not provide any evidence for the decay, but are not inconsistent with the above assumption. On the contrary a considerably smaller lifetime, less, for instance, than 1 × sec., would be inconsistent with most of the experimental results. There is no evidence that the mesotrons which have been stopped actually disintegrate into an electron and a neutrino.
DOI:https://doi.org/10.1103/RevModPhys.11.296
©1939 American Physical Society