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

ANNIS 1952

Annis, M.; Bridge, H.S.; Courant, H.; Olbert, S.; Rossi, B.;
Nuovo Cim. 9 (1952) 624;

Discusses two events observed in a multiplate cloud chamber operated at 3260 m and triggered by a penetrating shower detector. In each case a charged particle comes to rest in a lead plate and gives rise to a single secondary of near minimum ionization. It is concluded from the observed range and scattering that the secondary particle cannot be an electron. The mass of the primary is estimated as 1420+910-450 electron masses. In addition a further three events of this kind have been observed where it is not certain that the secondary particle is not a decay electron but the primary appears to be heavier than a or -meson. If it is assumed that these three events also represent the decay of S-particles the mass of the primary deduced from all five events is 1780+690-450 electron masses. (Science Abstracts, 1952, 8483. H. Elliot).

Accelerator COSM Detectors CLOUD

Related references
More (earlier) information appears in
H. S. Bridge and M. Annis, Phys. Rev. 82 (1951) 445;
B. Rossi, H. S. Bridge, and M. Annis, Rend. Lincei 11 (1951) 73;
Analyse data from
C. O'Ceallaigh, Phil. Mag. 42 (1951) 1032;

  charged charged (neutrals)

Particles studied
  heavy ex, mass

Record comments
Confirmation of the existence of heavy charged unstable particles.
  New Comments List of Comments