Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for ...discrepancies with the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for ``bumps'' that could indicate resonant production of new particles; and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in 2.0/fb of ppbar collisions at sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.
We present a measurement of the mass difference between top (t) and antitop (t) quarks using tt candidate events reconstructed in the final state with one lepton and multiple jets. We use the full ...data set of Te vatren radicals = 1.96 TeV proton-antiproton collisions recorded by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb super(-1). We estimate event by event the mass difference to construct templates for top pair signal events and background events. The resulting mass difference distribution in data compared to signal and background templates using a likelihood fit yields Delta M sub(top) = M sub(t) - M sub(t) = -1.95 + or - 1.11 (stat) + or - 0.59(syst) GeV/c super(2) and is in agreement with the standard model prediction of no mass difference.
We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data ...correspond to total integrated luminosities of up to 9.7fb-1 per experiment. The t-channel cross section is measured to be σt=2.25-0.31+0.29pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in σs+t=3.30-0.40+0.52pb, without assuming the standard model value for the ratio σs/σt. The resulting value of the magnitude of the top-to-bottom quark coupling is |Vtb|=1.02-0.05+0.06, corresponding to |Vtb| > 0.92 at the 95% C.L.
An inclusive search for the standard model Higgs boson using the four-lepton final state in proton-antiproton collisions produced by the Tevatron at radicals = 1.96 TeV is conducted. The data are ...recorded by the CDF II detector and correspond to an integrated luminosity of 9.7 fb super(-1). Three distinct Higgs decay modes, namely ZZ, WW, and tautau, are simultaneously probed. Nine potential signal events are selected and found to be consistent with the background expectation. We set a 95% credibility limit on the production cross section times the branching ratio and subsequent decay to the four-lepton final state for hypothetical Higgs boson masses between 120 GeV /c super(2) and 300 GeV /c super(2).
We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B^0 mesons in decays to B^{(*)+}\pi^- using 1.7/fb of data collected by the CDF II detector at the Fermilab ...Tevatron. The mass and width of the B^{*0}_2 state are measured to be m(B^{*0}_2) = 5740.2^{+1.7}_{-1.8}(stat.) ^{+0.9}_{-0.8}(syst.) MeV/c^2 and \Gamma(B^{*0}_2) = 22.7^{+3.8}_{-3.2}(stat.) ^{+3.2}_{-10.2}(syst.) MeV/c^2. The mass difference between the B^{*0}_2 and B^0_1 states is measured to be 14.9^{+2.2}_{-2.5}(stat.) ^{+1.2}_{-1.4}(syst.) MeV/c^2, resulting in a B^0_1 mass of 5725.3^{+1.6}_{-2.2}(stat.) ^{+1.4}_{-1.5}(syst.) MeV/c^2. This is currently the most precise measurement of the masses of these states and the first measurement of the B^{*0}_2 width.
We present the result of a search for a massive color-octet vector particle, (e.g. a massive gluon) decaying to a pair of top quarks in proton–antiproton collisions with a center-of-mass energy of ...1.96 TeV. This search is based on 1.9 fb−1 of data collected using the CDF detector during Run II of the Tevatron at Fermilab. We study tt¯ events in the lepton+jets channel with at least one b-tagged jet. A massive gluon is characterized by its mass, decay width, and the strength of its coupling to quarks. These parameters are determined according to the observed invariant mass distribution of top quark pairs. We set limits on the massive gluon coupling strength for masses between 400 and 800 GeV/c2 and width-to-mass ratios between 0.05 and 0.50. The coupling strength of the hypothetical massive gluon to quarks is consistent with zero within the explored parameter space.
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