W+WW^{+} W^{-} production and triple gauge boson couplings at LEP energies up to 183-GeV

Collaboration
Oct, 1998
49 pages
Published in:
  • Eur.Phys.J.C 8 (1999) 191-215
e-Print:
Report number:
  • CERN-EP-98-167
Experiments:

Citations per year

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Abstract:
A study of W-pair production in e+e- annihilations at Lep2 is presented, based on 877 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 +- 0.61 (stat.) +- 0.26 (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 +- 1.2 (stat.) +- 0.5 (syst.)%. The number of W-pair candidates and the angular distributions for each final state (qqlnu,qqqq,lnulnu) are used to determine the triple gauge boson couplings. After combining these values with our results from lower centre-of-mass energies we obtain D(kappa_g)=0.11+0.52-0.37, D(g^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 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+-0.091(stat.)+-0.023(syst.). All these measurements are consistent with the Standard Model expectations.
  • electron positron: colliding beams
  • electron positron: annihilation
  • W: pair production
  • W: hadronic decay
  • W: leptonic decay
  • angular distribution
  • W: branching ratio
  • lepton: universality
  • coupling: (3gauge boson)
  • W: polarization