Study of quark fragmentation in e/sup +/e/sup -/ annihilation at 29 GeV: Charged-particle multiplicity and single-particle rapidity distributions

Journal Article · Mon Dec 01 04:00:00 EST 1986 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.34.3304· OSTI ID:6930144

Derrick, M; Gan, K K; Kooijman, P; Loos, J S; Musgrave, B; Price, L E; Repond, J; Schlereth, J; Sugano, K; Weiss, J M

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-31109-ENG-38; AC02-76ER01112; AC03-76SF00098; AC02-76ER01428
• OSTI ID: 6930144
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 34:11; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645102* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BASIC INTERACTIONS
CHARGED PARTICLES
DEEP INELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
FRAGMENTATION
GEV RANGE
GEV RANGE 10-100
HADRON-HADRON INTERACTIONS
INELASTIC SCATTERING
INTERACTIONS
JET MODEL
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-LEPTON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LUMINOSITY
MATHEMATICAL MODELS
MULTIPLE PRODUCTION
MULTIPLICITY
OPTICAL PROPERTIES
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PARTICLE RAPIDITY
PEP STORAGE RINGS
PHYSICAL PROPERTIES
POSTULATED PARTICLES
QUARKS
SCATTERING
STORAGE RINGS