Measurement of trilinear gauge boson couplings WWV, (V≡Z,γ) in e+e− collisions at 189 GeV

Abstract Measurements of the trilinear gauge boson couplings WWγ and WWZ are presented using the data taken by DELPHI in 1998 at a centre-of-mass energy of 189 GeV and combined with DELPHI data at 183 GeV. Values are determined for Δg 1 Z and Δκ γ , the differences of the WWZ charge coupling and of the WWγ dipole coupling from their Standard Model values, and for λ γ , the WWγ quadrupole coupling. A measurement of the magnetic dipole and electric quadrupole moment of the W is extracted from the results for Δκ γ and λ γ . The study uses data from the final states jj l ν , jjjj , l X , jjX and γX , where j represents a quark jet, l an identified lepton and X missing four-momentum. The observations are consistent with the predictions of the Standard Model.