Measurement of R and Search for New Heavy Quarks in $e^+ e^-$ Annihilation at 50-{GeV} and 52-{GeV} Center-of-mass Energies

The total cross section for the process of the e + e - annihilation into hadrons has been measured at the centre-of-mass energies of 50 GeV and 52 GeV and a search has been made for new heavy quarks. The ratios R = σ ( e + e - → hadrons )/ σ point ( e + e - → μ + μ - ) obtained are 4.4±0.5 at 50 GeV and 4.7±0.3 at 52 GeV, respectively. An additional systematic uncertainty is 10%. From the event shape analysis we found no evidence for a new quark with charge 2 3 e .

ELECTRON POSITRON: COLLIDING BEAMS
COLLIDING BEAMS: ELECTRON POSITRON
ELECTRON POSITRON: ANNIHILATION
ANNIHILATION: ELECTRON POSITRON
HADRON: MULTIPLE PRODUCTION
MULTIPLE PRODUCTION: HADRON
HADRON: ELECTROPRODUCTION
ELECTROPRODUCTION: HADRON
CROSS SECTION: HADRONIC
SEARCH FOR: TOP

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Measurement of R and Search for New Heavy Quarks in e+e−e^+ e^-e+e− Annihilation at 50-{GeV} and 52-{GeV} Center-of-mass Energies

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Measurement of R and Search for New Heavy Quarks in $e^+ e^-$ Annihilation at 50-{GeV} and 52-{GeV} Center-of-mass Energies