1. |
- Aaltonen, T., et al.
(författare)
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Combination of Tevatron Searches for the Standard Model Higgs Boson in the W+W- Decay Mode
- 2010
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061802-
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Tidskriftsartikel (refereegranskat)abstract
- We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162-166 GeV at the 95% C.L.
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2. |
- Aaltonen, T., et al.
(författare)
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Evidence for a Particle Produced in Association with Weak Bosons and Decaying to a Bottom-Antibottom Quark Pair in Higgs Boson Searches at the Tevatron
- 2012
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 109:7, s. 071804-
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Tidskriftsartikel (refereegranskat)abstract
- We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron p (p) over bar collisions at root s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.
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3. |
- Aaltonen, T., et al.
(författare)
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Combination of CDF and D0 W-Boson mass measurements
- 2013
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:5, s. 052018-
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Tidskriftsartikel (refereegranskat)abstract
- We summarize and combine direct measurements of the mass of the W boson in root s = 1.96 TeV proton-antiproton collision data collected by CDF and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from CDF and D0 are combined with the two latest, more precise measurements: a CDF measurement in the electron and muon channels using data corresponding to 2.2 fb(-1) of integrated luminosity, and a D0 measurement in the electron channel using data corresponding to 4.3 fb(-1) of integrated luminosity. The resulting Tevatron average for the mass of the W boson is M-W = 80387 +/- 16 MeV. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of M-W = 80385 +/- 15 MeV.
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4. |
- Aaltonen, T., et al.
(författare)
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Combination of measurements of the top-quark pair production cross section from the Tevatron Collider
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7
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Tidskriftsartikel (refereegranskat)abstract
- We combine six measurements of the inclusive top-quark pair (t(sic)) production cross section (sigma(t)(sic)) from data collected with the CDF and D0 detectors at the Fermilab Tevatron with proton-antiproton collisions at root s = 1.96 TeV. The data correspond to integrated luminosities of up to 8.8 fb(-1). We obtain a value of sigma tt = 7.60 +/- 0.41 pb for a top-quark mass of m(t) = 172.5 GeV. The contributions to the uncertainty are 0.20 pb from statistical sources, 0.29 pb from systematic sources, and 0.21 pb from the uncertainty on the integrated luminosity. The result is in good agreement with the standard model expectation of 7.35(-0.33)(+0.28) pb at next-to-next-to-leading order and next-to-next-to leading logarithms in perturbative QCD.
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5. |
- Aaltonen, T., et al.
(författare)
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Higgs boson studies at the Tevatron
- 2013
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:5, s. 052014-
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Tidskriftsartikel (refereegranskat)abstract
- We combine searches by the CDF and D0 Collaborations for the standard model Higgs boson with mass in the range 90-200 GeV/c(2) produced in the gluon-gluon fusion, WH, ZH, t (t) over barH, and vector boson fusion processes, and decaying in the H -> b (b) over bar, H -> W+W-, H -> ZZ, H -> tau(+)tau(-), and H -> gamma gamma modes. The data correspond to integrated luminosities of up to 10 fb(-1) and were collected at the Fermilab Tevatron in p (p) over bar collisions at root s = 1.96 TeV. The searches are also interpreted in the context of fermiophobic and fourth generation models. We observe a significant excess of events in the mass range between 115 and 140 GeV/c(2). The local significance corresponds to 3.0 standard deviations at m(H) = 125 GeV/c(2), consistent with the mass of the Higgs boson observed at the LHC, and we expect a local significance of 1.9 standard deviations. We separately combine searches for H -> b (b) over bar, H -> W+W-, H -> tau(+)tau(-), and H -> gamma gamma. The observed signal strengths in all channels are consistent with the presence of a standard model Higgs boson with a mass of 125 GeV/c(2).
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6. |
- Aaltonen, T., et al.
(författare)
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Observation of s-Channel Production of Single Top Quarks at the Tevatron
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:23
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Tidskriftsartikel (refereegranskat)abstract
- We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The measured cross section is sigma(s) = 1.29(-0.24)(+0.26) pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 x 10(-10), corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.
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7. |
- Abazov, V. M., et al.
(författare)
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Model-independent measurement of t-channel single top quark production in p(p)over-bar collisions at,root s=1.96 TeV
- 2011
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 705:4, s. 313-319
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Tidskriftsartikel (refereegranskat)abstract
- We present a model-independent measurement of t-channel electroweak production of single top quarks in p collisions at root s = 1.96 TeV. Using 5.4 fb(-1) of integrated luminosity collected by the DO detector at the Fermilab Tevatron Collider, and selecting events containing an isolated electron or muon, missing transverse energy and one or two jets originating from the fragmentation of b quarks, we measure a cross section sigma (p (p) over bar -> tqb + X) = 2.90 +/- 0.59 (stat + syst) pb for a top quark mass of 172.5 GeV. The probability of the background to fluctuate and produce a signal as large as the one observed is 1.6 x 10(-8), corresponding to a significance of 5.5 standard deviations. (C) 2011 Elsevier B.V. All rights reserved.
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8. |
- Abazov, V. M., et al.
(författare)
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Search for CP violation in B-s(0) -> mu(+) D-s(-) X decays in p(p)over-bar collisions at root s=1.96 TeV
- 2010
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Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 82:1, s. 012003-
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Tidskriftsartikel (refereegranskat)abstract
- We have performed a search for CP violation in a sample of B-s(0) -> mu+Ds-X decays corresponding to 5 fb(-1) of proton-antiproton collisions collected by the D0 detector in Run II at the Fermilab Tevatron Collider. New physics in B-s(0) mixing could contribute a significant CP violating weak phase, which would be observed as a difference in the decay-time distribution for B-s(0) -> (B) over bar (0)(s) oscillated states versus that for (B) over bar (0)(s) -> B-s(0). A fit to the decay-time distributions of the B-s(0)/(B) over bar (0)(s) candidates yields the flavor-specific asymmetry as a(fs)(s) = [-1.7 +/- 9.1(stat)(-1.5)(+1.4)(syst) x 10(-3), which excludes CP violation due to new physics within the experimental sensitivity.
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9. |
- Abazov, V. M., et al.
(författare)
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Azimuthal decorrelations and multiple parton interactions in gamma+2 jet and gamma+3 jet events in p(p)over-bar collisions at root s=1.96 TeV
- 2011
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Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 83:5, s. 052008-
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Tidskriftsartikel (refereegranskat)abstract
- Samples of inclusive gamma + 2 jet and gamma + 3 jet events collected by the D0 experiment with an integrated luminosity of about 1 fb(-1) in p (p) over bar collisions at root s = 1.96 TeV are used to measure cross sections as a function of the angle in the plane transverse to the beam direction between the transverse momentum (p(T)) of the gamma + leading jet system (jets are ordered in p(T)) and p(T) of the other jet for gamma + 2 jet, or p(T) sum of the two other jets for gamma + 3 jet events. The results are compared to different models of multiple parton interactions (MPI) in the PYTHIA and SHERPA Monte Carlo (MC) generators. The data indicate a contribution from events with double parton (DP) interactions and are well-described by predictions provided by the PYTHIA MPI models with p(T)-ordered showers and by SHERPA with the default MPI model. The gamma + 2 jet data are also used to determine the fraction of events with DP interactions as a function of the azimuthal angle and as a function of the second jet p(T).
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10. |
- Abazov, V. M., et al.
(författare)
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Bounds on an Anomalous Dijet Resonance in W plus jets Production in p(p)over-bar Collisions at root s=1.96 TeV
- 2011
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 107:1, s. 011804-
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Tidskriftsartikel (refereegranskat)abstract
- We present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W boson in data corresponding to an integrated luminosity of 4.3 fb(-1) collected with the D0 detector at root s = 1.96 TeV. We find no evidence for anomalous resonant dijet production and derive upper limits on the production cross section of an anomalous dijet resonance recently reported by the CDF Collaboration, investigating the range of dijet invariant mass from 110 to 170 GeV/c(2). The probability of the D0 data being consistent with the presence of a dijet resonance with 4 pb production cross section at 145 GeV/c(2) is 8 x 10(-6).
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