W boson polarisation at LEP2

G Abbiendi; C Ainsley; PF Åkesson; G Alexander; J Allison; P Amaral; G Anagnostou; KJ Anderson; S Arcelli; S Asai; D Axen; G Azuelos; I Bailey; E Barberio; T Barillari; RJ Barlow; RJ Batley; P Bechtle; T Behnke; KW Bell; PJ Bell; G Bella; A Bellerive; G Benelli; S Bethke; O Biebel; O Boeriu; P Bock; M Boutemeur; S Braibant; L Brigliadori; RM Brown; K Buesser; HJ Burckhart; S Campana; RK Carnegie; AA Carter; JR Carter; CY Chang; DG Charlton; C Ciocca; J Couchman; A Csilling; M Cuffiani; S Dado; A de Roeck; EA de Wolf; K Desch; B Dienes; M Donkers; J Dubbert; E Duchovni; G Duckeck; IP Duerdoth; E Etzion; F Fabbri; L Feld; P Ferrari; F Fiedler; I Fleck; M Ford; A Frey; P Gagnon; JW Gary; G Gaycken; C Geich-Gimbel; G Giacomelli; P Giacomelli; M Giunta; J Goldberg; E Gross; J Grunhaus; M Gruwé; PO Günther; A Gupta; C Hajdu; M Hamann; GG Hanson; A Harel; M Hauschild; CM Hawkes; R Hawkings; RJ Hemingway; G Herten; RD Heuer; JC Hill; K Hodman; D Horváth; P Igo-Kemenes; K Ishii; H Jeremie; P Jovanovic; TR Junk; N Kanaya; J Kanzaki; D Karlen; K Kawagoe; T Kawamoto; RK Keeler; RG Kellogg

Journal article

W boson polarisation at LEP2

G Abbiendi, C Ainsley, PF Åkesson, G Alexander, J Allison, P Amaral, G Anagnostou, KJ Anderson, S Arcelli, S Asai, D Axen, G Azuelos, I Bailey, E Barberio, T Barillari, RJ Barlow, RJ Batley, P Bechtle, T Behnke, KW Bell Show all

Physics Letters Section B Nuclear Elementary Particle and High Energy Physics | Published : 2004

DOI: 10.1016/j.physletb.2004.02.003

Abstract

Elements of the spin density matrix for W bosons in e+e -→W+W -→qq̄′ℓνℓ events are measured from data recorded by the OPAL detector at LEP. This information is used to calculate polarised differential cross-sections and to search for CP-violating effects. Results are presented for W bosons produced in e+e - Collisions with centre-of-mass energies between 183 GeV and 209 GeV. The average fraction of W bosons that are longitudinally polarised is found to be (23.9±2.1±1.1)% compared to a Standard Model prediction of (23.9±0.1)%. All results are consistent with CP conservation. © 2004 Elsevier B.V. All rights reserved.