Chronology of Milestone Events in Particle Physics - BRIDGE 1951
Chronology of Milestone Events in Particle Physics


Bridge, H.S.; Annis, M.;
A Cloud-Chamber Study of The New Unstable Particles
Phys. Rev. 82 (1951) 445;

In a set of pictures taken with a large multiple-plate cloud chamber at 700 g cm-2 atmospheric depth, we have observed 10 examples of tracks that deviate suddenly in the gas of the chamber. These are similar to the "V'' tracks reported by Rochester and Butler, by Seriff, Leighton, Hsiao, Cowan, and Anderson, and recently by Fretter. Of these 10 events, 4 can be interpreted as neutral-particle decays, 4 as charged-particle decays, while 2 are uncertain as to type.
Of the 4 neutral-particle decays, 2 show one of the decay products ionizing heavily and stopping in a plate. In 2 cases it is possible to say from ionization, range, and scattering that one of the decay products is probably a meson. (Extracted from the introductory part of the paper.).

Accelerator COSM Detectors CLOUD

Related references
Analyse data from
G. D. Rochester and C. C. Butler, Nature 160 (1947) 855;
U. Camerini, P. H. Fowler, W. O. Lock, and H. Muirhead, Phil. Mag. 41 (1950) 413;
W. B. Fretter, Phys. Rev. 82 (1951) 294;
A. J. Seriff et al., Phys. Rev. 78 (1950) 290;

  neutral 2charged
  charged charged (neutrals)

Particles studied
  charged ex, mass
  neutral ex, mass

Record comments
Further confirmation of the existence of heavy unstable particles.
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