Chronology of Milestone Events in Particle Physics - BRANDELIK 1979H
Chronology of Milestone Events in Particle Physics

BRANDELIK 1979H

TASSO collaboration; Brandelik, R. et al.
Evidence for Planar Events in e+ e– Annihilation at High Energies
Phys. Lett. 86B (1979) 243;

Reprinted in
R. N. Cahn and G. Goldhaber, The Experimental Foundations of Particle Physics, Cambridge Univ. Press (1991) 322.

Abstracts
Hadron jets produced in e+e– annihilation between 13 GeV and 31.6 GeV in c.m. at PETRA are analyzed. The transverse momentum of the jets is found to increase strongly with c.m. energy. The broadening of the jets is not uniform in azimuthal angle around the quark direction but tends to yield planar events with large and growing transverse momenta in the plane and smaller transverse momenta normal to the plane. The simple q anti-q collinear jet picture is ruled out. The observation of planar events shows that there are three basic particles in the final state. Indeed several events with three well-separated jets of hadrons are observed at the highest energies. This occurs naturally when the outgoing quark radiates a hard noncollinear gluon, i.e., e+e– → q anti-q gluon with the quarks and the gluons fragmenting into hadrons with the limited transverse momenta.

Accelerator DESY-PETRA Detectors TASSO

Related references
See also
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Reactions
  e+ e– 2hadron (hadrons) 13,17-31.6 GeV (Ecm) pt, p
  e+ e– (jets) 2jet 13,17-31.6 GeV (Ecm) pt, p
  e+ e– q anti-q gluon 13,17-31.6 GeV (Ecm) ang
  q jet
  anti-q jet
  gluon jet

Particles studied
  gluon ex

Record comments
Confirmation of the production of gluon jets.
    
  New Comments List of Comments


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