Observation of Jet Structure in High pTp_{T} Events at the ISR and the Importance of Parton Transverse Momentum

Mar, 1977
42 pages
Published in:
  • Nucl.Phys.B 127 (1977) 1
  • Published: 1977
Report number:
  • CERN-EP-PHYS-77-10

Citations per year

19771988199920102021010203040
Abstract: (Elsevier)
Events with a charged particle of high transverse momentum were studied in pp collisions at √ s = 52.5 GeV with the Split Field magnet (SFM) at the CERN-ISR, triggering on a charged particle of p T > 2 GeV/ c , in the c.m. angular region θ ≅ 20° and θ ≅ 45°. The results provide further evidence for jet-like structure in high p T reactions. One of two produced jets is associated with the triggering hadron whereas the other is produced at an azimuthal angle that differs from that of the trigger by roughly 180°. The main features of the data are found to agree with the predictions of a simple parton-parton hard scattering model with vector gluon exchange, provided that one allows for partons in the proton to have transverse momentum. The ingredients of the model are all derived from data on deep inelastic lepton-proton scattering and from hadron production in e + e − annihilation. The model retains a simple p T −4 dependence for the parton-parton scattering. However, for p T ≲ 4GeV/ c , the transverse movement of partons yields an approximate p T −8 scaling for the inclusive hadron distribution in agreement with observations. For the understanding of our data, it is found to be essential to take into account the soft component arising from the fragmentation of the spectator partons into hadrons.
  • P P: COLLIDING BEAMS
  • COLLIDING BEAMS: P P
  • P P: INCLUSIVE REACTION
  • CHARGED PARTICLE: PRODUCTION
  • PRODUCTION: CHARGED PARTICLE
  • TRANSVERSE MOMENTUM: HIGH
  • SPECTRUM: RAPIDITY
  • CORRELATION: RAPIDITY
  • MULTIPLE PRODUCTION: JET
  • SCALING: VIOLATION