Study of hadronization using energy flow from e/sup +/e/sup -/ annihilation into quarks and gluons at. sqrt. s of 29 GeV

Technical Report · Fri Nov 01 04:00:00 EST 1985

DOI:https://doi.org/10.2172/6290682· OSTI ID:6290682

Rosenberg, L J

We have made a high statistics study of QCD jets produced in e/sup +/e/sup -/ annihilations at ..sqrt..s of 29 GeV and observed in the MAC detector located at the PEP storage ring at SLAC. The MAC detector uses calorimetry and provides a homogeneous response over much of its 98% . 4..pi.. sr instrumented solid angle. A data sample of well reconstructed hadronic events was selected by requiring that E/sub vis/ in the calorimeters be near ..sqrt..s, and almost all the energy be deposited in the central calorimeters. Fits of the jet transverse energy flow are made to the data using String (STR) model and several types of Independent Jet (IJM) model hypotheses, where ..alpha../sub s/, the strong coupling constant, and sigma/sub q/, the width of the secondary quark P/sub perpendicular/ distribution, are free parameters. The fits to O(..alpha../sub s//sup 2/ using MS-bar renormalization yield ..alpha../sub s/ approx.0.17 with the STR hypothesis, and ..alpha../sub s/ approx.0.12 with the various IJM hypotheses. The correlations between ..alpha../sub s/ and sigma/sub q/ are examined. Detailed comparisons were made with other experimental results. The energy flow projected onto the event plane of 3-jet events selected from the above data sample was studied. The data shows an asymmetric energy flow around the thin jet. Such an asymmetry was predicted by the STR model, and a cluster model (Webber) incorporating soft gluon interference. The various IJM models show no such asymmetry. We associate this asymmetry with coherence effects during hadronization. 106 refs., 58 figs., 18 tabs.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (USA)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 6290682
• Report Number(s): SLAC-289; ON: DE86004700
• Country of Publication: United States
• Language: English

Related Subjects

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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR DISTRIBUTION
ANNIHILATION
BASIC INTERACTIONS
COMPOSITE MODELS
DATA
DIAGRAMS
DISTRIBUTION
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXPERIMENTAL DATA
EXTENDED PARTICLE MODEL
FIELD THEORIES
GEV RANGE
GEV RANGE 10-100
GLUONS
HADRONS
INFORMATION
INTERACTIONS
JET MODEL
JETS
LEPTON-LEPTON INTERACTIONS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PEP STORAGE RINGS
POSTULATED PARTICLES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARK MODEL
QUARKS
RADIATION DETECTORS
SCATTERPLOTS
SHOWER COUNTERS
STORAGE RINGS
STRING MODELS