Comparison of three-jet and radiative two-jet events in electron-position annihilation at 29 GeV

Thesis/Dissertation · Tue Dec 31 23:00:00 EST 1985

OSTI ID:5552389

Sheldon, P D

By comparing S-jet (e..gamma..e/sup -/ ..-->.. q anti qg) and radiative 2-jet (e/sup +/e/sup -/ ..-->.. q anti q..gamma..) events from electron-positron annihilation, we have studied the local and global effects of the presence of a hard bremsstrahlung gluon in hadronic events. Globally, we observe a depletion of hadrons in q anti qg events relative to q anti q..gamma.. events on the opposite side of the event plane from the gluon, in the angular region between the q and anti q jets. This depletion is shown to be in agreement with the predictions of Quantum Chromodynamics. The existence of this effect demonstrates that the presence of a gluon significantly alters the color forces and hence the fragmentation process in hadronic events. We also use these q anti q..gamma.. and q anti qg events to compare low energy (4.5 GeV) gluon and quark jets. Our data indicate that gluon jets have softer x/sub p/ distributions than quark jets, while the transverse momentum distributions of these two types of jets are identical within our errors. Although we are unable to determine if the multiplicities of gluon (n/sub g/) and quark (n/sub q/) jets are different, the ratio n/sub g//n/sub q/ = 9/4 predicted asymptotically in QCD would not be consistent with our data.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 5552389
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Electromagnetic Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BASIC INTERACTIONS
BREMSSTRAHLUNG
DATA
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXPERIMENTAL DATA
FIELD THEORIES
GEV RANGE
GEV RANGE 10-100
GLUONS
HADRONS
INFORMATION
INTERACTIONS
JET MODEL
LEPTON-LEPTON INTERACTIONS
LINEAR MOMENTUM
MASSLESS PARTICLES
MATHEMATICAL MODELS
MULTIPLE PRODUCTION
MULTIPLICITY
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PEP STORAGE RINGS
PHOTONS
POSTULATED PARTICLES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
RADIATIONS
STORAGE RINGS
TRANSVERSE MOMENTUM