Abstract
We report on an improved measurement of the mass of theZ 0 boson, its total width and its partial decay widths into hadrons and leptons, as well as the effective axial vector and vector couplings to charged leptons. These measurements are based on a data set of approximately 160 000 hadronicZ 0 decays and 18 000 decays into electrons, muons and taus, recorded by the OPAL experiment at centre of mass energies near the mass of theZ 0. The total width and the partial widths to visible final states, derived from the measured cross sections, are used to extract the invisible width. The effective couplings of theZ 0 to charged leptons are studied using measurements of the lepton pair cross sections and forward-backward asymmetries at the different centre of mass energy points of theZ 0 scan. The implications of our results in the context of the Standard Model are discussed.
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On leave from Research Institute for Computer Peripherals, Hangzhou, China
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OPAL Collaboration., Alexander, G., Allison, J. et al. Measurement of theZ 0 line shape parameters and the electroweak couplings of charged leptons. Z. Phys. C - Particles and Fields 52, 175–207 (1991). https://doi.org/10.1007/BF01560437
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DOI: https://doi.org/10.1007/BF01560437