Study of quark fragmentation in e/sup +/e/sup -/ annihilation at 29 GeV: Charged-particle multiplicity and single-particle rapidity distributions
This paper presents the charged-particle multiplicity distributions for e/sup +/e/sup -/ annihilation at ..sqrt..s = 29 GeV measured in the High Resolution Spectrometer. The data, which correspond to an integrated luminosity of 185 pb/sup -1/, were obtained at the SLAC e/sup +/e/sup -/ storage ring PEP. The techniques used to correct the observed prong numbers are discussed. The multiplicity distribution of the charged particles has a mean value = 12.87 +- 0.03 +- 0.30, a dispersion D/sub 2/ = 3.67 +- 0.02 +- 0.18, and an f/sub 2/ moment of 0.60 +- 0.02 +- 0.18. Results are also presented for a two-jet sample selected with low sphericity and aplanarity. The charged-particle distributions are almost Poissonian and narrower than have been reported by other e/sup +/e/sup -/ experiments in this energy range. The mean multiplicity increases with the event sphericity, and for the sample of threefold-symmetric three-jet events, a value of = 16.3 +- 0.3 +- 0.7 is found. No correlation is observed between the multiplicities in the two hemispheres when the events are divided into two jets by a plane perpendicular to the thrust axis. This result is in contrast with the situation in soft hadronic collisions, where a strong forward-backward correlation is measured. For the single jets, a mean multiplicity of 6.43 +- 0.02 +- 0.15 and a dispersion value of D/sub 2/ = 2.55 +- 0.02 +- 0.13 are found. These values give further support to the idea of independent jet fragmentation. The multiplicity distributions are well fit by the negative-binomial distribution.
- Research Organization:
- Argonne National Laboratory, Argonne, Illinois 60439
- DOE Contract Number:
- W-31-109-ENG-38; AC02-76ER01112; AC03-76SF00098; AC02-76ER01428
- OSTI ID:
- 6930144
- Journal Information:
- Phys. Rev. D; (United States), Vol. 34:11
- Country of Publication:
- United States
- Language:
- English
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Multiplicity distributions in e/sup +/e/sup -/ annihilation at 29 GeV: a comparison with hadronic data
Study of quark fragmentation in e/sup +/e/sup -/ annihilation at 29 GeV: charged particle multiplicity distributions
Related Subjects
ELECTRON-POSITRON INTERACTIONS
ANNIHILATION
MULTIPLE PRODUCTION
QUARKS
FRAGMENTATION
CHARGED PARTICLES
DEEP INELASTIC SCATTERING
GEV RANGE 10-100
HADRON-HADRON INTERACTIONS
JET MODEL
LEPTON-NUCLEON INTERACTIONS
LUMINOSITY
MULTIPLICITY
PARTICLE RAPIDITY
PEP STORAGE RINGS
BASIC INTERACTIONS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
GEV RANGE
INELASTIC SCATTERING
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-LEPTON INTERACTIONS
MATHEMATICAL MODELS
OPTICAL PROPERTIES
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
POSTULATED PARTICLES
SCATTERING
STORAGE RINGS
645102* - High Energy Physics- Particle Interactions & Properties-Experimental- Weak Interactions & Properties