production and triple gauge boson couplings at LEP energies up to 183 GeV
The OPAL Collaboration
G. Abbiendi 2 - et al.
2Dipartimento di Fisica dell' Università di Bologna and INFN, I-40126 Bologna, Italy
Received: 23 October 1998 / Published online: 1 March 1999
A study of W-pair production in annihilations at LEP is presented, based on candidates corresponding to an integrated luminosity of at 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 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 %. The number of W-pair candidates and the angular distributions for each final state (,are used to determine the triple gauge boson couplings. After combining these values with our results from lower centre-of-mass energies we obtain , and ,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 . All these measurements are consistent with the Standard Model expectations.