Search for WW and WZ Production in Lepton Plus Jets Final States at CDF

We present a search for WW and WZ production in final states that contain a charged lepton (electron or muon) and at least two jets, produced in s**(1/2) =1.96 TeV p anti-p collisions at the Fermilab Tevatron, using data corresponding to 1.2 fb-1 of integrated luminosity collected with the CDF II detector. Diboson production in this decay channel has yet to be observed at hadron colliders due to the large single W plus jets background. An artificial neural network has been developed to increase signal sensitivity, as compared with an event selection based on conventional cuts. We set a 95% confidence level upper limit of sigma_WW x BR(W --> ell_nu_ell, W --> jets) + sigma_WZ x BR(W --> ell_nu_ell, Z --> jets) < 2.88 pb, which is consistent with the standard model next to leading order cross section calculation for this decay channel of 2.09 +/- 0.12 pb