Direct Observation of Longitudinally Polarised W Bosons
arXiv:hep-ex/0001016 · doi:10.1016/S0370-2693(99)01489-6
Abstract
The three different helicity states of W bosons, produced in the reaction e+e- -> W+W- -> l nu q q~ are studied using leptonic and hadronic W decays at sqrt{s}=183GeV and 189GeV. The W polarisation is also measured as a function of the scattering angle between the W- and the direction of the e- beam. The analysis demonstrates that W bosons are produced with all three helicities, the longitudinal and the two transverse states. Combining the results from the two center-of-mass energies and with leptonic and hadronic W decays, the fraction of longitudinally polarised W bosons is measured to be 0.261 +/- 0.051(stat.) +/- 0.016(syst.) in agreement with the expectation from the Standard Model.
References in corpus (3)
Cited by in corpus (4)
- Measurement of W Polarisation at LEP
- Anomalous quartic WWgammagamma and WWZgamma couplings through WWZ production in gamma gamma colliders
- W physics at the ILC with polarized beams as a probe of the Littlest Higgs Model
- Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP