Danysz, M.; Pniewski, J.; Delayed Disintegration of a Heavy Nuclear Fragment
Phil. Mag. 44 (1953) 348;
A remarkable coincidence of two events recorded in a photographic emulsion has recently been observed in this laboratory. It occurred in a G5 emulsion, 600 thick, which had been exposed to cosmic radiation at an altitude of 85 000 feet, and consists of two stars marked A and B in the photo-micrograph reproduced in Plate 13. The centre of the star B coincides with the end of the track of a heavy fragment ejected from the star A. If the coincidence is not accidental,
it must be considered as an example of the delayed disintegration of a heavy fragment. The probability of a fortuitous coincidence is very small, and it therefore seemed appropriate to analyse the events more closely. It is clear, of course, that any novel conclusions drawn from a single observation should be treated with proper reserve. (Extracted from the introductory part of the paper.).
First evidence for a hypernucleus.