We report on a measurement of the D+-meson production cross section as a function of transverse momentum (pT) in proton-antiproton (p$\bar{p}$) collisions at 1.96 TeV center-of-mass energy, using the ...full data set collected by the Collider Detector at Fermilab in Tevatron Run II and corresponding to 10 fb-1 of integrated luminosity. We use D+→K-π+π+ decays fully reconstructed in the central rapidity region |y|<1 with transverse momentum down to 1.5 GeV/c, a range previously unexplored in p$\bar{p}$ collisions. Inelastic p$\bar{p}$ scattering events are selected online using minimally biasing requirements followed by an optimized offline selection. The K-π+π+ mass distribution is used to identify the D+ signal, and the D+ transverse impact-parameter distribution is used to separate prompt production, occurring directly in the hard-scattering process, from secondary production from b-hadron decays. We obtain a prompt D+ signal of 2950 candidates corresponding to a total cross section σ(D+,1.5<pT<14.5 GeV/c,|y|<1)=71.9±6.8(stat)±9.3(syst) μb. While the measured cross sections are consistent with theoretical estimates in each pT bin, the shape of the observed pT spectrum is softer than the expectation from quantum chromodynamics. The results are unique in p$\bar{p}$ collisions and can improve the shape and uncertainties of future predictions.
The first search for single-top-quark production from the exchange of an s -channel virtual W boson using events with an imbalance in the total transverse energy, b -tagged jets, and no identified ...leptons is presented. Assuming the electroweak production of top quarks of mass 172.5 GeV / c 2 in the s channel, a cross section of 1.1 2 $+ 0.61\atop{- 0.57}$ ( stat + syst ) pb with a significance of 1.9 standard deviations is measured. This measurement is combined with the result obtained from events with an imbalance in total transverse momentum, b -tagged jets, and exactly one identified lepton, yielding a cross section of 1.3 6$+ 0.37\atop{- 0.32}$ ( stat + syst ) pb, with a significance of 4.2 standard deviations.
We report on a measurement of the fraction of events with a W or Z boson produced diffractively in antiproton-proton collisions at a center of mass energy of 1.96 TeV, using data from 0.6 inverse ...femtobarns of integrated luminosity collected with the CDF-II detector equipped with a Roman-pot spectrometer that detects the antiproton (pbar) from pbar+p --> pbar+X+W/Z. We find that (0.97 +/- 0.11)% of Ws and (0.85 +/- 0.22)% of Zs are produced diffractively in a region of (anti)proton fractional momentum loss (\xi) of 0.03< \xi <0.10 and 4-momentum transferred squared t of -1 p+X+W/Z+pbar, and on exclusive Z production, pbar+p-->pbar+Z+p. No signal is seen above background for these processes, and comparisons are made with expectations.
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