Multiplicity distributions in e/sup +/e/sup -/ annihilation at 29 GeV

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5524118

Derrick, M

This paper presents the charged particle multiplicity distributions of e/sup +/e/sup -/ annihilation at ..sqrt.. s = 29 GeV measured in the High Resolution Spectrometer. The data, which corresponds to an integrated luminosity of 185 pb/sup -1/, were obtained at the e/sup +/e/sup -/ storage ring PEP. The multiplicity distribution of the charged particles has a mean value < n > = 12.87 +- 0.03 +- 0.30, a dispersion D/sub 2/ = 3.67 +- 0.02 +- 0.18, and an f/sub 2/ momentum 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 results 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 three-fold-symmetric three-jet events, a value of < n > = 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. For the single jets, a mean multiplicity of < n > = 6.43 +- 0.02 +- 0.15 and 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. 20 refs., 13 figs.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5524118
• Report Number(s): ANL-HEP-CP-86-26; CONF-860440-3; ON: DE86012111
• Country of Publication: United States
• Language: English

Related Subjects

645102* -- High Energy Physics-- Particle Interactions &amp; Properties-Experimental-- Weak Interactions &amp; Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BASIC INTERACTIONS
DATA
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ENERGY RANGE
EXPERIMENTAL DATA
GEV RANGE
GEV RANGE 10-100
INFORMATION
INTERACTIONS
JETS
LEPTON-LEPTON INTERACTIONS
MAGNETIC SPECTROMETERS
MEASURING INSTRUMENTS
MULTIPLICITY
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PARTICLE RAPIDITY
SPECTROMETERS