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Register a new userMeasurement of the $WW$ and $WZ$ production cross section using final states with a charged lepton and heavy-flavor jets in the full CDF Run II data set
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We present a measurement of the total {it WW} and {it WZ} production cross sections in $pbar{p}$ collision at $sqrt{s}=1.96$ TeV, in a final state consistent with leptonic $W$ boson decay and jets originating from heavy-flavor quarks from either a $W$ or a $Z$ boson decay. This analysis uses the full data set collected with the CDF II detector during Run II of the Tevatron collider, corresponding to an integrated luminosity of 9.4 fb$^{-1}$. An analysis of the dijet mass spectrum provides $3.7sigma$ evidence of the summed production processes of either {it WW} or {it WZ} bosons with a measured total cross section of $sigma_{WW+WZ} = 13.7pm 3.9$~pb. Independent measurements of the {it WW} and {it WZ} production cross sections are allowed by the different heavy-flavor decay-patterns of the $W$ and $Z$ bosons and by the analysis of secondary-decay vertices reconstructed within heavy-flavor jets. The productions of {it WW} and of {it WZ} dibosons are independently seen with significances of $2.9sigma$ and $2.1sigma$, respectively, with total cross sections of $sigma_{WW}= 9.4pm 4.2$~pb and $sigma_{WZ}=3.7^{+2.5}_{-2.2}$~pb. The measurements are consistent with standard-model predictions.
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We present a measurement of the ZZ boson-pair production cross section in 1.96 TeV center-of-mass energy ppbar collisions. We reconstruct final states incorporating four charged leptons or two charged leptons and two neutrinos from the full data set collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.7 fb-1 of integrated luminosity. Combining the results obtained from each final state, we measure a cross section of 1.04(+0.32)(-0.25) pb, in good agreement with the standard model prediction at next-to-leading order in the strong-interaction coupling.
We present a new method to measure the top quark pair production cross section and the background rates with 2.7 fb$^{-1}$ of data from $pbar{p}$ collisions at $sqrt{s} =1.96$ TeV collected with the CDF II Detector. The size of the dataset was chosen to directly show the improvements of this new method. We select events with a single electron or muon, missing transverse energy, and at least one b-tagged jet. We perform a simultaneous fit to a jet flavor discriminant across nine samples defined by the number of jets and b-tags. We measure a top cross section of $sigma_{tbar{t}} = 7.64 pm 0.57 mathrm{(stat + syst)} pm 0.45 mathrm{(luminosity)}$ pb. An advantage of this approach is that many systematic uncertainties are measured in situ and inversely scale with integrated luminosity.
We measure the forward--backward asymmetry of the production of top quark and antiquark pairs in proton-antiproton collisions at center-of-mass energy $sqrt{s} = 1.96~mathrm{TeV}$ using the full data set collected by the Collider Detector at Fermilab (CDF) in Tevatron Run II corresponding to an integrated luminosity of $9.1~rm{fb}^{-1}$. The asymmetry is characterized by the rapidity difference between top quarks and antiquarks ($Delta y$), and measured in the final state with two charged leptons (electrons and muons). The inclusive asymmetry, corrected to the entire phase space at parton level, is measured to be $A_{text{FB}}^{tbar{t}} = 0.12 pm 0.13$, consistent with the expectations from the standard-model (SM) and previous CDF results in the final state with a single charged lepton. The combination of the CDF measurements of the inclusive $A_{text{FB}}^{tbar{t}}$ in both final states yields $A_{text{FB}}^{tbar{t}}=0.160pm0.045$, which is consistent with the SM predictions. We also measure the differential asymmetry as a function of $Delta y$. A linear fit to $A_{text{FB}}^{tbar{t}}(|Delta y|)$, assuming zero asymmetry at $Delta y=0$, yields a slope of $alpha=0.14pm0.15$, consistent with the SM prediction and the previous CDF determination in the final state with a single charged lepton. The combined slope of $A_{text{FB}}^{tbar{t}}(|Delta y|)$ in the two final states is $alpha=0.227pm0.057$, which is $2.0sigma$ larger than the SM prediction.
We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of sqrt{s} = 1.96 TeV using a data set corresponding to 7.5 fb-1 of integrated luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process t to Wb to l{ u}b by requiring the presence of an electron or muon, a large imbalance of transverse momentum indicating the presence of a neutrino, and two or three jets including at least one originating from a bottom quark. An artificial neural network is used to discriminate the signal from backgrounds. We measure a single top quark production cross section of 3.04+0.57-0.53 pb and set a lower limit on the magnitude of the coupling between the top quark and bottom quark |Vtb| > 0.78 at the 95% credibility level.
A measurement of the inclusive production cross section of isolated prompt photons in proton-antiproton collisions at center-of-mass energy $sqrt{s}$=1.96TeV is presented. The results are obtained using the full Run II data sample collected with the Collider Detector at the Fermilab Tevatron, which corresponds to an integrated luminosity of 9.5fb$^{-1}$. The cross section is measured as a function of photon transverse energy, $E_T^{gamma}$, in the range 30$ < E_T^{gamma} <$500GeV and in the pseudorapidity region $|eta^{gamma}|<$1.0. The results are compared with predictions from parton-shower Monte Carlo models at leading order in quantum chromodynamics (QCD) and from next-to-leading order perturbative QCD calculations. The latter show good agreement with the measured cross section.
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