Quark fragmentation in e/sup +/e/sup -/ annihilation at 29 GeV

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6045297

Baranko, G J

Experimental data are presented concerning the production of hadrons by quark fragmentation in positron-electron annihilations at a center-of-mass energy of 29 GeV. The data have been collected by the High Resolution Spectrometer collaboration (HRS) as part of the Positron Electron Project (PEP) at the Stanford Linear Accelerator Center (SLAC). A description is given of the construction and operation of the HRS. Various properties of the charged particles which measure the degree to which dynamical effects are visible in the fragmentation process, are shown for annihilation events where the initially produced quark and antiquark evolve into two back-to-back jets of particles. The results are compared to hadron production in other types of collision processes. The total hadronic sample corresponds to an integrated luminosity of 19.6 pb/sup -1/. By requiring the Sphericity and Aplanarity variables, which describe the event shape, to be less than .25 and .1 respectively, and the Thrust axis to be greater than 45/sup 0/ from the beamline, a sample of 3629 two-jet events contained in the central region of the detector was selected from the total hadronic sample. For these two-jet events, the mean charged multiplicity was measured to be 12.0 +/- 0.2. The multiplicity distribution is approximately described by a form that is similar to a Poisson distribution which is derived from a simplified cascade model of the fragmentation. Comparison of the multiplicity distribution is also made to other e+ e- and p anti-p data in KNO variables. Single particle distributions are presented for longitudinal and transverse components of momenta with respect to the Thrust axis as well as the corrected rapidity distribution.

• Research Organization: Indiana Univ., Bloomington (USA)
• OSTI ID: 6045297
• 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
CORRELATIONS
DATA
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXPERIMENTAL DATA
GEV RANGE
GEV RANGE 10-100
HADRONS
HYPOTHESIS
INFORMATION
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
LIMITING FRAGMENTATION
MULTIPLE PRODUCTION
MULTIPLICITY
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PARTICLE RAPIDITY
PEP STORAGE RINGS
POSTULATED PARTICLES
QUARKS
STORAGE RINGS