We analyze a sample of W + jet events collected with the Collider Detector at Fermilab (CDF) in ppbar collisions at sqrt(s) = 1.8 TeV to study ttbar production. We employ a simple kinematical variable "H", defined as the scalar sum of the transverse energies of the lepton, neutrino and jets. For events with a W boson and four or more jets, the shape of the "H" distribution deviates by 3.8 standard deviations from that expected from known backgrounds to ttbar production. However this distribution agrees well with a linear combination of background and ttbar events, the agreement being best for a top mass of 180 GeV/c^2.
We present a study of events with W bosons and hadronic jets produced in pbar p collisions at a center of mass energy of 1.8 TeV. The data consist of 51400 W^+/- -> e^+/- nu decay candidates from 108 pb^-1 of integrated luminosity collected with the CDF detector at the Tevatron Collider. The cross sections and jet production properties have been measured for W + \geq 1 to \geq 4 jet events. The data are compared to predictions of leading order QCD matrix element calculations with added gluon radiation and simulated fragmentation.
We present a study of events with W bosons and hadronic jets produced in p¯p collisions at a center of mass energy of 1.8 TeV. The data consist of 51400 W→eν decay candidates from 108 pb−1 of integrated luminosity collected using the CDF detector at the Fermilab Tevatron collider. Cross sections and jet production properties have been measured for W+>~1 to >~4 jet events. The data compare well to predictions of leading-order QCD matrix element calculations with added gluon radiation and simulated parton fragmentation.
We present results of a search for W+W− production through the leptonic decay channel W+W−→l+l−νν¯ in p¯p collisions at s=1.8TeV. In a 108pb−1 data sample recorded with the Collider Detector at Fermilab, five W+W− candidates are found with an expected standard model background of 1.2±0.3 events. The W+W− production cross section is measured to be σ(p¯p→W+W−)=10.2−5.1+6.3(stat)±1.6(syst)pb, in agreement with the standard model prediction. Limits on WWγ and WWZ anomalous couplings are presented.
We have searched for the rare decay W±→π±+γ in 83 pb−1 of data taken in proton-antiproton collisions at s=1.8 TeV with the Collider Detector at Fermilab. We find three events in the signal region and estimate the background to be 5.2±1.5 events. We set a 95% confidence level upper limit of 7×10−4 on the ratio of partial widths, Γ(W±→π±+γ)/Γ(W±→e±+ν).
We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 $pb^{-1}$ of $p\bar{p}$ collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both $p\bar{p} \to \gamma \gamma + X$ and $p \bar{p} \to \gamma \gamma + W/Z$. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale $\sqrt{F}$ in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for $H \to \gamma \gamma$. Finally, we set a lower limit on the mass of a 'bosophilic' Higgs boson (e.g. one which couples only to $\gamma, W,$ and $Z$ bosons with standard model couplings) of 82 GeV/$c^2$ at 95% confidence level.
The ratio of the W+≥1 jet cross section to the inclusive W cross section is measured using W±→e±ν events from p¯p collisions at s=1.8TeV. The data are from 108pb−1 of integrated luminosity collected with the Collider Detector at Fermilab. Measurements of the cross section ratio for jet transverse energy thresholds (ETmin) ranging from 15 to 95 GeV are compared to theoretical predictions using next-to-leading-order QCD calculations. Data and theory agree well for ETmin>25GeV, where the predictions lie within 1 standard deviation of the measured values.
We present the first measurement of the production cross section of a W boson with a single charm quark (c) in p-pbar collisions at sqrt(s)=1.96 TeV, using soft muon tagging of c jets. In a data sample of ~1.8 fb-1, recorded with the CDF II detector at the Fermilab Tevatron, we select events with W+1 or 2 jets. We use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the Wc signal. We measure sigma_{Wc}(p_{Tc}>20 GeV/c, |\eta_c|<1.5)\times BR(W->\ell\nu) = 9.8+/-3.2 pb, in agreement with theoretical expectations.
A search for a heavy charged gauge boson, W ′, using the decay channels W ′ → eν and W′ → τν → eνν ν is reported. The data used in the analysis were collected by the DØ experiment at the Fermilab Tevatron during the 1992-93 p p collider run from an integrated luminosity of 13.9 ± 0.8 pb −1 at s =1.8 TeV . Assuming that the neutrino from W ′ decay is stable and has a mass significantly less than m W ′ , an upper limit at the 95% confidence level is set on the cross section times branching ratio for p p → W′ → eν . A W ′ with the same couplings to quarks and leptons as the standard model W boson is excluded for m W ′ < 610 GeV/c 2 .
We present a measurement of the W+W- production cross section using 184/pb of ppbar collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W+W- -> l+l-vvbar, where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0+2.2-0.8 events. The resulting W+W- production cross section measurement of sigma(ppbar -> W+W-) = 14.6 +5.8 -5.1 (stat) +1.8 -3.0 (syst) +-0.9 (lum) pb agrees well with the Standard Model expectation.
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