Measurement of the azimuthal angle distribution of leptons from <em><strong>W</strong></em> boson decays as a function of the <em><strong>W</strong></em> transverse momentum in <em>pp</em> collisions at s√=1.8  TeV

We present the first measurement of the A2 and A3 angular coefficients of the W boson produced in proton-antiproton collisions. We study W→eνe and W→μνμ candidate events produced in association with at least one jet at CDF, during Run Ia and Run Ib of the Tevatron at s√=1.8 TeV. The corresponding integrated luminosity was 110 pb−1. The jet balances the transverse momentum of the W and introduces QCD effects in W boson production. The extraction of the angular coefficients is achieved through the direct measurement of the azimuthal angle of the charged lepton in the Collins-Soper rest-frame of the W boson. The angular coefficients are measured as a function of the transverse momentum of the W boson. The electron, muon, and combined results are in good agreement with the standard model prediction, up to order α2s in QC