Chronology of Milestone Events in Particle Physics - ARMENTEROS 1952
Chronology of Milestone Events in Particle Physics


Armenteros, R.; Barker, K.H.; Butler, C.C.; Cachon, A.; York, C.M.;
The Properties of Charged V Particles
Phil. Mag. 43 (1952) 597;

Twenty one examples of the decay of charged V-particles have been found among 25000 counter-controlled cloud-chamber photographs obtained on the Pic-du-Midi.
These events have been analysed and compared with the data obtained by other groups. The measurements show that, if the majority of the V-tracks are produced by one type of particle having a single mode of decay, there must be at least two neutral secondary particles, in addition to the charged secondary particle. The latter is probably a - or a -meson and the combined mass of the neutral particles must be less than 1000me. Since the -particles, of mass about 1200me, which were discovered in photographic emulsions, also decay into a charged meson and at least two neutral particles, it is plausible to assume provisionally, that the V-particles and the -particles are the same. On this assumption most of the available data concerning V and -particles can be explained if the unstable particle has a mass of about 1200me and decays into a charged -meson, a o-meson and a neutrino, or alternatively into a charged -meson and two neutrinos. As yet no direct evidence has been found for the existence of a o-meson in the decay scheme. One negatively charged V-particle probably produced a neutral V-track and a charged meson.

Accelerator COSM Detectors CLOUD

Related references
More (earlier) information appears in
R. Armenteros et al., Nature 167 (1951) 501;
R. Armenteros, K. H. Barker, C. C. Butler, and A. Cachon, Phil. Mag. 42 (1951) 1113;
See also
C. C. Butler, W. G. V. Rosser, and K. H. Barker, Proc. Roy. Soc. 63 (1950) 145;
C. C. Butler, Progress in Cosmic Ray Physics, (North Holland Publishing Co.) (1951) 110;
P. H. Fowler, M. G. K. Menon, C. F. Powell, and O. Rochat, Phil. Mag. 42 (1951) 1040;
M. G. K. Menon, Report given at Bristol Conference in December (1951);
O. Kofoed-Hansen, Phil. Mag. 42 (1951) 1411;
R. B. Leighton, S. D. Wanlass, and W. L. Alford, Phys. Rev. 83 (1951) 843;
C. O'Ceallaigh, Phil. Mag. 42 (1951) 1032;
G. D. Rochester and C. C. Butler, Nature 160 (1947) 855;
A. J. Seriff et al., Phys. Rev. 78 (1950) 290;
R. W. Thompson, H. O. Cohn, and R. S. Flum, Phys. Rev. 83 (1951) 175;
J. Trembley, Report given at Bristol Conference in December (1951);
P. Astbury et al., Report given at Bristol Conference in December (1951);
H. S. Bridge and M. Annis, Phys. Rev. 82 (1951) 445;
W. B. Fretter, Phys. Rev. 83 (1951) 1053;

Particles studied

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First evidence for the hyperon.
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