OPAL Collaboration (1999) W+W− production and triple gauge boson couplings at LEP energies up to 183 GeV. European Physical Journal C: Particles and Fields, 8 (2). pp. 191-215. ISSN 1434-6044
Full text not available from this repository.Abstract
A study of W-pair production in e+e−e+e− annihilations at LEP is presented, based on 877W+W−877W+W− candidates corresponding to an integrated luminosity of 57 pb −1−1 at s√=183s=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.)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.)67.9±1.2(stat.)±0.5(syst.) %. The number of W-pair candidates and the angular distributions for each final state ( qq¯ℓ¯νℓqq¯ℓ¯νℓ , qq¯qq¯,ℓ¯νℓℓ′ν¯ℓ′)qq¯qq¯,ℓ¯νℓℓ′ν¯ℓ′) are used to determine the triple gauge boson couplings. After combining these values with our results from lower centre-of-mass energies we obtain Δκγ=0.11+0.52−0.37Δκγ=0.11−0.37+0.52 , Δgz1=0.01+0.13−0.12Δg1z=0.01−0.12+0.13 and λ=−0.10+0.13−0.12λ=−0.10−0.12+0.13 , 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±0.091(stat.)±0.023(syst.)0.242±0.091(stat.)±0.023(syst.) . All these measurements are consistent with the Standard Model expectations.