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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Exclusion of an Exotic Top Quark with-4/3 Electric Charge Using Soft Lepton Tagging Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 105 Issue 10 Pages 101801 - 7pp
Keywords
Abstract We present a measurement of the electric charge of the top quark using p (p) over bar collisions corresponding to an integrated luminosity of 2: 7 fb(-1) at the CDF II detector. We reconstruct t (t) over bar events in the lepton + jets final state. We use soft lepton taggers to determine the flavor of the b jets, which we use to reconstruct the top quark's electric charge and exclude an exotic top quark with -4/3 charge at 95% confidence level. This is the strongest exclusion of the exotic charge scenario and the first to use soft leptons for this purpose.
Address [Aaltonen, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; van Remortel, N.] Univ Helsinki, Div High Energy Phys, Dept Phys, FIN-00014 Helsinki, Finland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000281406900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 274
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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Search for the Production of Scalar Bottom Quarks in p(p)over-bar Collisions at root s=1.96 TeV Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 105 Issue 8 Pages 081802 - 7pp
Keywords
Abstract We report on a search for direct scalar bottom quark (sbottom) pair production in p (p) over bar collisions at root s = 1.96 TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65 fb(-1) of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70 GeV/c(2), sbottom masses up to 230 GeV/c(2) are excluded at 95% confidence level.
Address [Aaltonen, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; van Remortel, N.] Univ Helsinki, Dept Phys, Div High Energy Phys, FIN-00014 Helsinki, Finland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000281071800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 276
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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Measurement of W-Boson Polarization in Top-Quark Decay in p(p)over-bar Collisions at root s=1.96 TeV Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 105 Issue 4 Pages 042002 - 8pp
Keywords
Abstract We report measurements of the polarization of W bosons from top-quark decays using 2.7 fb(-1) of p (p) over bar collisions collected by the CDF II detector. Assuming a top-quark mass of 175 GeV/c(2), three measurements are performed. A simultaneous measurement of the fraction of longitudinal (f(0)) and right-handed (f(0)) W bosons yields the model- independent results f(0) =0. 88 +/- 0.11(stat) +/- 0.06(syst) and f(+) = 0.15 +/- 0.07(stat) +/- 0.06(syst) with a correlation coefficient of -0.59. A measurement of f(0) [f(+)] constraining f(+) [f(0)] to its standard model value of 0.0 [0.7] yields f(0) 0.70 + 0.07(stat) +/- 0.04(syst) [f(+) – 0.01 +/- 0.02(stat) +/- 0.05(syst)]. All these results are consistent with standard model expectations. We achieve the single most precise measurements of f(0) for both the model- independent and modeldependent determinations.
Address [Aaltonen, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; Torre, S.; van Remortel, N.] Univ Helsinki, Div High Energy Phys, Dept Phys, FIN-00014 Helsinki, Finland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000280234400009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 279
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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Measurement of the Ratio sigma(t(t)over-bar)/sigma(Z/gamma*-> ll) and Precise Extraction of the t(t)over-bar Cross Section Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 105 Issue 1 Pages 012001 - 7pp
Keywords
Abstract We report a measurement of the ratio of the t (t) over bar to Z/gamma* production cross sections in root s = 1.96 TeV p (p) over bar collisions using data corresponding to an integrated luminosity of up to 4.6 fb(-1), collected by the CDF II detector. The t (t) over bar cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/gamma* -> ll cross section predicted by the standard model, the extracted t (t) over bar cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result sigma(t (t) over bar) = 7.70 +/- 0.52 pb, for a top-quark mass of 172.5 GeV/c(2).
Address [Blair, R. E.; Byrum, K. L.; LeCompte, T.; Nodulman, L.; Paramanov, A. A.; Wagner, R. G.; Wicklund, A. B.] Argonne Natl Lab, Argonne, IL 60439 USA
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000279273300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 282
Permanent link to this record
 

 
Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Direct Top-Quark Width Measurement at CDF Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume (down) 105 Issue 23 Pages 232003 - 7pp
Keywords
Abstract We present a measurement of the top-quark width in the lepton + jets decay channel of t (t) over bar events produced in p (p) over bar collisions at Fermilab's Tevatron collider and collected by the CDF II detector. From a data sample corresponding to 4.3 fb(-1) of integrated luminosity, we identify 756 candidate events. The top-quark mass and the mass of the hadronically decaying W boson that comes from the top-quark decay are reconstructed for each event and compared with templates of different top-quark widths (Gamma(t)) and deviations from nominal jet energy scale (Delta(JES)) to perform a simultaneous fit for both parameters, where Delta(JES) is used for the in situ calibration of the jet energy scale. By applying a Feldman-Cousins approach, we establish an upper limit at 95% confidence level (CL) of Gamma(t) < 7.6 GeV and a two-sided 68% CL interval of 0.3 GeV < Gamma(t) < 4.4 GeV for a top-quark mass of 172.5 GeV/c(2), which are consistent with the standard model prediction.
Address [Aaltonen, T.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R.] Univ Helsinki, Dept Phys, Div High Energy Phys, FIN-00014 Helsinki, Finland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000286736800007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 518
Permanent link to this record