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Register a new userMeasurement of the inclusive leptonic asymmetry in top-quark pairs that decay to two charged leptons at CDF
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We measure the inclusive forward-backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton-antiproton collisions, and decaying to final states that contain two charged leptons (electrons or muons), using data collected with the Collider Detector at Fermilab. With an integrated luminosity of 9.1 $rm{fb}^{-1}$, the leptonic forward-backward asymmetry, $A_{text{FB}}^{ell}$, is measured to be $0.072 pm 0.060$ and the leptonic pair forward-backward asymmetry, $A_{text{FB}}^{ellell}$, is measured to be $0.076 pm 0.082$, compared with the standard model predictions of $A_{text{FB}}^{ell} = 0.038 pm 0.003$ and $A_{text{FB}}^{ellell} = 0.048 pm 0.004$, respectively. Additionally, we combine the $A_{text{FB}}^{ell}$ result with a previous determination from a final state with a single lepton and hadronic jets and obtain $A_{text{FB}}^{ell} = 0.090^{+0.028}_{-0.026}$.
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The leptonic asymmetry in semileptonic ttbar decays is measured with the CDF detector using the full Tevatron Run II dataset, which corresponds to 9.4 fb^-1 of integrated luminosity. The measured asymmetry is extrapolated to the full kinematic range and the measured value of A_FB^lep = 0.094^+0.032_-0.029 is compared to the NLO prediction A_FB^lep = 0.038 +/- 0.003.
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 present a measurement of the top quark mass (Mtop) in the all-hadronic decay channel using 5.8 fb^{-1} of proton-antiproton data collected with the CDF II detector at the Fermilab Tevatron Collider. Events with 6 to 8 jets are selected by a neural network algorithm and by the requirement that at least one of the jets is tagged as a b quark jet. The measurement is performed by a likelihood fit technique, which determines simultaneously Mtop and the jet energy scale (JES) calibration. The fit yields a value of 172.5 +- 1.4(stat) +-1.0(JES) +-1.1(syst) GeV/c^2.
We present a precision measurement of the top-quark mass using the full sample of Tevatron $sqrt{s}=1.96$ TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 $fb^{-1}$. Using a sample of $tbar{t}$ candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the $W$ boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with {it in situ} calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, $mtop = 172.85 $pm$ 0.71 (stat) $pm$ 0.85 (syst) GeV/c^{2}.$
We report evidence for $s$-channel single-top-quark production in proton-antiproton collisions at center-of-mass energy $sqrt{s}= 1.96 mathrm{TeV}$ using a data set that corresponds to an integrated luminosity of $9.4 mathrm{fb}^{-1}$ collected by the Collider Detector at Fermilab. We select events consistent with the $s$-channel process including two jets and one leptonically decaying $W$ boson. The observed significance is $3.8$ standard deviations with respect to the background-only prediction. Assuming a top-quark mass of $172.5 mathrm{GeV}/c^2$, we measure the $s$-channel cross section to be $1.41^{+0.44}_{-0.42} mathrm{pb}$.
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