256 research outputs found

    Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV

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    We present a measurement of the top quark pair production cross section in pp̄ collisions at s=1.96TeV using 318pb-1 of data collected with the Collider Detector at Fermilab. We select tt̄ decays into the final states eν+jets and μν+jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178GeV/c2, we measure a cross section of 8.7±0.9(stat)-0. 9+1.1(syst)pb. We also report the first observation of tt̄ with significance greater than 5σ in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1-1.4+1.6(stat)-1.3+2.0(syst) pb. © 2006 The American Physical Society

    Search for long-lived doubly charged Higgs bosons in p(p)over-bar collisions at root s=1.96 TeV

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    We present a search for long-lived doubly charged Higgs bosons (H+/-+/-), with signatures of high ionization energy loss and muonlike penetration. We use 292 pb(-1) of data collected in p (p) over bar collisions at root s=1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude H-L(+/-+/-) and H-R(+/-+/-) bosons with masses below 133 GeV/c(2) and 109 GeV/c(2), respectively. In the degenerate case we exclude H+/-+/- mass below 146 GeV/c(2). All limits are quoted at the 95% confidence level

    Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events

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    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.Comment: 8 pages, 2 figures, 2 tables. To be submitted to Physical Review Letter

    Initial building investigations at aberdeen proving ground maryland building e5375

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    As part of a building decommissioning and demolition program at Aberdeen Proving Ground, a detailed inspection of each target building is being conducted in order to characterize and describe the state of the building as it currently exists and to identify areas potentially contaminated with toxic or other hazardous substances. Room surfaces, drains and sumps, remaining equipment, and such associated exterior aboveground and underground appurtenances as tanks and pipelines are among the features, generically termed compartments, that may be potentially contaminated. Detailed drawings are being prepared for each building to illustrate the existing structure. This report presents the results of the inspection of Building E5375 in the Edgewood/Canal Creek area of Aberdeen Proving Ground. Nine potentially contaminated compartments were identified in this building and its vicinity. Document type: Repor

    Initial building investigations at aberdeen proving ground maryland building e5190

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    As part of a building decommissioning and demolition program at Aberdeen Proving Ground, a detailed inspection of each target building is conducted in order to characterize and describe the state of the building as it currently exists and to identify areas potentially contaminated with toxic or other hazardous substances. Room surfaces, drains and sumps, remaining equipment, and such associated exterior aboveground and underground appurtenances as tanks and pipelines are among the features, generically termed compartments, that may be potentially contaminated. Detailed drawings are prepared to illustrate the existing structure of each building. This report presents the results of the inspection of building E5190 in the Edgewood/Canal Creek area of Aberdeen Proving Ground. This building houses a 10,000-gal tank formerly used to store xylene. Eleven potentially contaminated compartments were identified in this building and its vicinity. Document type: Repor
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