Hard-photon processes in electron-positron annihilation at 29 GeV
The hard photon processes ..mu mu gamma.. and hadrons + ..gamma.. in e..gamma..e/sup -/ annihilation at 29 GeV have been studied. The study is based on an integrated luminosity of 226 pb/sup -1/ taken at PEP with the Mark II detector. For the ..mu mu gamma.. process, a small fraction of non-planar events are observed with missing momentum along the beam direction. The resulting missing energy spectrum is consistent with that expected from higher order effects. The observed cross section is consistent with the predicted cross section for this process, sigma/sup exp//sigma/sup th/ = .90 +/- .05 +/- .06. The observed hard photon energy spectrum and mass distributions are found to be in agreement with O (..cap alpha../sup 3/) QED. The measured charge asymmetry is in good agreement with the predicted value, A/sub exp//A/sub th/ = .83 +/- .25 +/- .12. The ..mu gamma.. invariant mass distribution is used to place a limit on a possible excited muon coupling G/sub ..gamma..//M* for excited muon masses in the range 1 < M* < 21 GeV of (G/sub ..gamma..//M*)/sup 2/ < 10/sup -5/ GeV/sup -2/ at a 95% confidence level. In the hadrons + ..gamma.. process, evidence for final state radiation is found in an excess of events over that predicted from initial state radiation alone of 253 +/- 54 +/- 60 events. Further evidence for final state radiation is found in a large hadronic charge asymmetry, A/sub Had/ + ..gamma.. = (-24.6 +/- 5.5)%.
- Research Organization:
- California Univ., Berkeley (USA)
- OSTI ID:
- 5775120
- Resource Relation:
- Other Information: Thesis (Ph.D)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ELECTRON-POSITRON INTERACTIONS
MULTIPLE PRODUCTION
PAIR PRODUCTION
PARTICLE PRODUCTION
HADRONS
MUONS
PHOTONS
ANNIHILATION
ASYMMETRY
CHARGE DISTRIBUTION
CROSS SECTIONS
EXPERIMENTAL DATA
FINAL-STATE INTERACTIONS
GAMMA SPECTRA
GEV RANGE 10-100
MASS SPECTRA
PEP STORAGE RINGS
BASIC INTERACTIONS
DATA
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GEV RANGE
INFORMATION
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
LEPTONS
MASSLESS PARTICLES
NUMERICAL DATA
PARTICLE INTERACTIONS
SPECTRA
STORAGE RINGS
645101* - High Energy Physics- Particle Interactions & Properties-Experimental- Electromagnetic Interactions & Properties