We present the first evidence of WW+WZ production with lepton+jets final states at a hadron collider. The data correspond to 1.07 inverse femtobarns of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider in proton-antiproton collisions at sqrt(s)=1.96 TeV. The observed cross section for WW+WZ production is 20.2 +/- 4.5 pb, consistent with the SM prediction of 16.1 +/- 0.9 pb. The probability for background fluctuations to produce an excess equal to or larger than that observed is estimated to be 5.4e-6, corresponding to a significance of 4.4 standard deviations.

Presented is a measurement of the simultaneous production of a W{sup ±} boson in association with a second weak boson (W{sup ±} or Z°) in p{bar p} collisions at √s = 1.96 TeV. Events are consider with one electron or one muon, missing transverse energy, and at least two hadronic jets. The data were collected by the D0 detector in Run IIa of the Tevatron accelerator and correspond to 1.07 fb−1 of integrated luminosity for each of the two channels (WW/WZ → e[nu]q{bar q} and WW/WZ → [mu][nu]q{bar q}). The cross section for WW + WZ production is measured to be 20.2 ± 2.5(stat) {+-} 3.6(sys) {+-} 1.2(lum) pb with a Gaussian significance of 4.4 standard deviations above the background-only scenario. This measurement is consistent with the Standard Model prediction and represents the first direct evidence for WW and WZ production with semi-leptonic decays at a hadron collider.

We present the results of a search for new particles that lead to a Z boson plus jets in p{bar p} collisions at √s = 1.96 TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 fb−1 collected using Z boson decays to ee and?? is used. We describe a completely data-based method to predict the dominant background from standard-model Z+jet events. This method can be similarly applied to other analyses requiring background predictions in multi-jet environments, as shown when validating the method by predicting the background from W+jets in t{bar t} production. No significant excess above the background prediction is observed, and a limit is set using a fourth generation quark model to quantify the acceptance. Assuming BR(b′ → bZ) = 100% and using a leading-order calculation of the b′ cross section, b′ quark masses below 268 GeV/c2 are excluded at 95% confidence level.

The authors report the results from a search for t{anti t} production in p{anti p} collisions at √s = 1.8 TeV with the D0 detector at Fermilab in the final states consisting of one isolated high p{sub T} lepton (e or?), multiple jets and a substantial missing transverse energy (E{sub T}), excluding the events that have?-tagged jets. Two independent analysis approaches lead them to similar estimates for the cross-section. They see no conclusive evidence for top production in the 13.5 pb−1 of data taken during the 1992--1993 run of the Tevatron.

The authors present results from a search for WZ production with subsequent decay to l[nu]l'{bar l}' (l and {ell}' = e or [mu]) using 0.30 fb−1 of data collected by the D0 experiment between 2002 and 2004 at the Tevatron. Three events with WZ decay characteristics are observed. With an estimated background of 0.71 ± 0.08 events, we measure the WZ production cross section to be 4.5{sub -2.6}{sup +3.8} pb, with a 95% C.L. upper limit of 13.3 pb. The 95% C.L. limits for anomalous WWZ couplings are found to be -2.0