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\(\mathrm{W^+W^-}\) production and triple gauge boson couplings at LEP energies up to 183 GeV

  • The OPAL Collaboration
  • G. Abbiendi et al.
Experimental physics

Abstract.

A study of W-pair production in \({\rm e^+e^-}\) annihilations at LEP is presented, based on \(877\,{\rm W^+W^-}\) candidates corresponding to an integrated luminosity of 57 pb\(^{-1}\) at \(\sqrt s=183\) GeV. Assuming that the angular distributions of the W-pair production and decay, as well as their branching fractions, are described by the Standard Model, the W-pair production cross-section is measured to be \(15.43\pm 0.61 ({\rm stat.}) \pm 0.26 ({\rm syst.})\) pb. Assuming lepton universality and combining with our results from lower centre-of-mass energies, the W branching fraction to hadrons is determined to be \(67.9 \pm 1.2 ({\rm stat.})\pm 0.5 ({\rm syst.})\)%. The number of W-pair candidates and the angular distributions for each final state (\({\rm q \bar q} \bar \ell \nu_\ell\), \({\rm q \bar q q \bar q}, \bar \ell \nu_\ell \ell^\prime \bar \nu_{\ell^\prime })\) are used to determine the triple gauge boson couplings. After combining these values with our results from lower centre-of-mass energies we obtain \(\Delta \kappa_\gamma = 0.11^{+0.52}_{-0.37}\), \(\Delta g^{\rm z}_1 = 0.01^{+ 0.13}_{-0.12}\) and \(\lambda = -0.10^{+0.13}_{-0.12}\), where the errors include both statistical and systematic uncertainties and each coupling is determined by setting the other two couplings to the Standard Model value. The fraction of W bosons produced with a longitudinal polarisation is measured to be \(0.242 \pm 0.091({\rm stat.}) \pm 0.023 ({\rm syst.})\). All these measurements are consistent with the Standard Model expectations.

Keywords

Angular Distribution Gauge Boson Systematic Uncertainty Model Expectation Longitudinal Polarisation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • The OPAL Collaboration
  • G. Abbiendi et al.
    • 1
  1. 1. Dipartimento di Fisica dell' Università di Bologna and INFN, I-40126 Bologna, Italy IT

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