Jet production in photon-photon collisions at PEP

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7103311

Zeitlin, C J

The inclusive process {gamma}{gamma} {yields} hadrons has been studied in e{sup +}e{sup {minus}} collisions at the Stanford Linear Accelerator storage ring PEP, using the TPC/Two-Gamma detector facility. The flux of bremsstrahlung photons from the incoming e{sup +} and e{sup {minus}} is calculable in Quantum Electrodynamics, allowing one to extract {gamma}{gamma} cross sections and other information according to {sigma}{sub ee{yields}eeX} = L{sigma}{sub {gamma}{gamma}{yields}X} where the luminosity function L describes the flux of virtual photons. In this thesis, the author will present a study of the jet structure of {gamma}{gamma} events where one of the outgoing e{sup {plus minus}} was detected in the small-angle spectrometer, meaning that the corresponding photon was substantially off its mass shell. The total cross section for {gamma}{gamma} production of hadrons has been measured as a function of both the invariant mass of the tagged photon (Q{sup 2}) and the {gamma}{gamma} center-of-mass energy W, in the range 0.2 < Q{sup 2} < 6.8 GeV{sup 2} and 2 < W < 10 GeV. The cross section measurement is an outgrowth of a study of the related quantity F{sub 2}{sup {gamma}}, the photon structure function. The cross section results are used as the input for the 2-jet models used in the jet analysis, in which thrust and sphericity are used to reconstruct the jet axis and measure p{sub T}{sup jet}. The excess of high-p{sub T} events seen in other experiments is confirmed, and other features of the data are shown to be consistent with multi-jet production. The data are compared to absolute predictions from QCD-based models where the structure function used in the hard scattering approximation is varied.

• Research Organization: California Univ., Davis, CA (USA)
• OSTI ID: 7103311
• Country of Publication: United States
• Language: English

Related Subjects

645000* -- High Energy Physics
645103 -- High Energy Physics-- Particle Interactions &amp; Properties-Experimental-- Strong Interactions &amp; Baryon &amp; Meson Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BASIC INTERACTIONS
CALCULATION METHODS
CROSS SECTIONS
DATA
DATA ANALYSIS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FIELD THEORIES
HADRONS
INFORMATION
INTERACTIONS
JET MODEL
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE MODELS
PEP STORAGE RINGS
PHOTON-PHOTON INTERACTIONS
PRODUCTION
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
STORAGE RINGS