| 1. |
- Eberhardson, Michael, et al.
(författare)
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Tumour necrosis factor inhibitors in Crohn's disease and the effect on surgery rates
- 2022
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Ingår i: Colorectal Disease. - : Wiley. - 1462-8910 .- 1463-1318. ; 24:4, s. 470-483
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Surgery is an important therapeutic option for Crohn's disease. The need for first bowel surgery seems to have decreased with the introduction of tumour necrosis factor inhibitors (TNFi; adalimumab or infliximab). However, the impact of TNFi on the need for intestinal surgery in Crohn's disease patients irrespective of prior bowel resection is not known. The aim of this work is to compare the incidence of bowel surgery in Crohn's disease patients who remain on TNFi treatment versus those who discontinue it. Method: We performed a nationwide register-based observational cohort study in Sweden of all incident and prevalent cases of Crohn's disease who started first-line TNFi treatment between 2006 and 2017. Patients were categorized according to TNFi treatment retention less than or beyond 1 year. The study cohort was evaluated with regard to incidence of bowel surgery from 12 months after the first ever TNFi dispensation. Results: We identified 5003 Crohn's disease patients with TNFi exposure: 3748 surgery naïve and 1255 with bowel surgery prior to TNFi initiation. Of these patients, 7% (n = 353) were subjected to abdominal surgery during the first 12 months after the start of TNFi and were subsequently excluded from the main analysis. A majority (62%) continued TNFi for 12 months or more. Treatment with TNFi for less than 12 months was associated with a significantly higher surgery rate compared with patients who continued on TNFi for 12 months or more (hazard ratio 1.26, 95% CI 1.09–1.46; p = 0.002). Conclusion: Treatment with TNFi for less than 12 months was associated with a higher risk of bowel surgery in Crohn's disease patients compared with those who continued TNFi for 12 months or more.
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| 2. |
- 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
-
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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| 3. |
- Abazov, M, et al.
(författare)
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A novel method for modeling the recoil in W boson events at hadron colliders
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 609:2-3, s. 250-262
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Tidskriftsartikel (refereegranskat)abstract
- We present a new method for modeling the hadronic recoil in W -> lv events produced at hadron colliders. The recoil is chosen from a library of recoils in Z -> ll data events and overlaid on a simulated W -> lv event. Implementation of this method requires that the data recoil library describe the proper-ties of the measured recoil as a function of the true, rather than the measured, transverse momentum of the boson. We address this issue using a multidimensional Bayesian unfolding technique. We estimate the statistical and systematic uncertainties from this method for the W boson mass and width measurements assuming 1 fb(-1) of data from the Fermilab Tevatron. The uncertainties are found to be small and comparable to those of a more traditional parameterized recoil model. For the highprecision measurements that will be possible with data from Run 11 of the Fermilab Tevatron and from the CERN LHC, the method presented in this paper may be advantageous, since it does not require an understanding of the measured recoil from first principles.
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| 4. |
- Abazov, M, et al.
(författare)
-
Combination of t(t)over-bar cross section measurements and constraints on the mass of the top quark and its decays into charged Higgs bosons
- 2009
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 80, s. 071102-
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Tidskriftsartikel (refereegranskat)abstract
- We combine measurements of the top quark pair production cross section in p (p) over bar collisions in the l + jets, ll, and tau l final states ( where l is an electron or muon) at a center of mass energy of root s = 1.96 TeV in 1 fb(-1) of data collected with the D0 detector. For a top quark mass of 170 GeV/c(2), we obtain sigma(t (t) over bar) = 8.18(-0.87)(+0.98) pb in agreement with the theoretical prediction. Based on predictions from higher order quantum chromodynamics, we extract a mass for the top quark from the combined t (t) over bar cross section, consistent with the world average of the top quark mass. In addition, the ratios of t (t) over bar cross sections in different final states are used to set upper limits on the branching fractions B(t -> H(+)b -> tau(+) vb) and B(t -> H(+)b -> c (s) over barb) as a function of the charged Higgs boson mass.
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| 5. |
- Abazov, M, et al.
(författare)
-
Direct Measurement of the Mass Difference between Top and Antitop Quarks
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:13, s. 132001-
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the mass difference between t and (t) over bar quarks in lepton + jets final states of t (t) over bar events in 1 fb(-1) of data collected with the D0 detector from Fermilab Tevatron Collider p (p) over bar collisions at root s = 1.96 TeV. The measured mass difference of 3.8 +/- 3.7 GeV is consistent with the equality of t and (t) over bar masses. This is the first direct measurement of a mass difference between a quark and its antiquark partner.
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| 6. |
- Abazov, M, et al.
(författare)
-
Direct Measurement of the W Boson Width
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:23, s. 231802-
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Tidskriftsartikel (refereegranskat)abstract
- We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W -> e nu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at s=1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.
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| 7. |
- Abazov, M, et al.
(författare)
-
Evidence of WW and WZ Production with lepton plus jets Final States in pp Collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:16, s. 161801-
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Tidskriftsartikel (refereegranskat)abstract
- We present first evidence for WW+WZ production in lepton+jets final states at a hadron collider. The data correspond to 1.07 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron in pp collisions at root s=1.96 TeV. The observed cross section for WW+WZ production is 20.2 +/- 4.5 pb, consistent with the standard model and more precise than previous measurements in fully leptonic final states. The probability that background fluctuations alone produce this excess is < 5.4x10(-6), which corresponds to a significance of 4.4 standard deviations.
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| 8. |
- Abazov, M, et al.
(författare)
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Measurement of B-s(0) Mixing Parameters from the Flavor-Tagged Decay B-s(0)-> J/psi phi
- 2008
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:24, s. 241801-:101, s. 241801-
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Tidskriftsartikel (refereegranskat)abstract
- From an analysis of the flavor-tagged decay B-s(0)-> J/psi phi we obtain the width difference between the B-s(0) light and heavy mass eigenstates, Delta Gamma(s)=0.19 +/- 0.07(stat)(-0.01)(+0.02)(syst) ps(-1), and the CP-violating phase, phi(s)=-0.57(-0.30)(+0.24)(stat)(-0.02)(+0.08)(syst). The allowed 90% CL intervals of Delta Gamma(s) and phi(s) are 0.06
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| 9. |
- Abazov, M, et al.
(författare)
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Measurement of differential Z/gamma* plus jet plus X cross sections in p(p)over-bar collisions at root S=1.96 TeV
- 2008
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 669:5, s. 278-286
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Tidskriftsartikel (refereegranskat)abstract
- We present new measurements of differential cross sections for Z/gamma* (-> mu mu) + jet + X production in a 1 fb(-1) data sample collected with the DO detector in p (p) over bar collisions at root s = 1.96 TeV. Results include the first measurements differential in the Z/gamma* transverse momentum and rapidity, as well as new measurements differential in the leading jet transverse momentum and rapidity. Next-to-leading order perturbative QCD predictions are compared to the measurements, and reasonable agreement is observed, except in the region of low Z/gamma* transverse momentum. Predictions from two event generators based on matrix elements and parton showers, and one pure parton shower event generator are also compared to the measurements. These show significant overall normalization differences to the data and have varied success in describing the shape of the distributions.
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| 10. |
- Abazov, M, et al.
(författare)
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Measurement of Dijet Angular Distributions at s=1.96 TeV and Searches for Quark Compositeness and Extra Spatial Dimensions
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:19, s. 191803-
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Tidskriftsartikel (refereegranskat)abstract
- We present the first measurement of dijet angular distributions in pp collisions at s=1.96 TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of 0.7 fb(-1) collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25 TeV to above 1.1 TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV-1 scale extra dimensions. For all models considered, we set the most stringent direct limits to date.
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| 11. |
- Abazov, M, et al.
(författare)
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Measurement of gamma + b + X and gamma + c + X Production Cross Sections in pp > Collisions at s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:19, s. 192002-
-
Tidskriftsartikel (refereegranskat)abstract
- First measurements of the differential cross sections d(3)sigma/(dp(T)(gamma)dy(gamma)dy(jet)) for the inclusive production of a photon in association with a heavy quark (b, c) jet are presented, covering photon transverse momenta 30 < p(T)(gamma)< 150 GeV, photon rapidities |y(gamma)|< 1.0, jet rapidities |y(jet)|< 0.8, and jet transverse momenta p(T)(jet)> 15 GeV. The results are based on an integrated luminosity of 1 fb(-1) in pp collisions at s=1.96 TeV recorded with the D0 detector at the Fermilab Tevatron Collider. The results are compared with next-to-leading order perturbative QCD predictions.
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| 12. |
- Abazov, M, et al.
(författare)
-
Measurement of the t(t)over-bar production cross section and top quark mass extraction using dilepton events in p(p)over-bar collisions
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 679:3, s. 177-185
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s = 1.96 TeV using approximately 1 fb(-1) collected with the DO detector. We consider decay channels containing two high p(T) charged leptons where one lepton is identified as an electron or a muon while the other lepton can be an electron, a muon or a hadronically decaying tau lepton. For a mass of the top quark of 170 GeV, the measured cross section is 7.5(-1.0)(+1.0)(stat)(-0.6)(+0.7)(syst)(-0.5)(+0.6)(lumi) pb. Using l tau events only, we measure: sigma(t (t) over bar) x B(t (t) over bar -> l tau b (b) over bar) = 0.13(-0.08)(+0.09)(stat)(-0.06)(+0.06)(syst)(-0.02)(+0.02)(lumi) pb. Comparing the measured cross section as a function of the mass of the top quark with a partial next-to-next-to leading order Quantum Chroniodynamics theoretical prediction, we extract a mass of the top quark of 171.5(-8.8)(+9-9) GeV, in agreement with direct measurements.
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| 13. |
- Abazov, M, et al.
(författare)
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Measurement of the W Boson Mass
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:14, s. 141801-
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the W boson mass in W -> e nu decays using 1 fb(-1) of data collected with the D0 detector during Run II of the Fermilab Tevatron collider. With a sample of 499830 W -> e nu candidate events, we measure M-W=80.401 +/- 0.043 GeV. This is the most precise measurement from a single experiment.
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| 14. |
- Abazov, M, et al.
(författare)
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Measurement of the WW Production Cross Section with Dilepton Final States in pp Collisions at s=1.96 TeV and Limits on Anomalous Trilinear Gauge Couplings
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:19, s. 191801-
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Tidskriftsartikel (refereegranskat)abstract
- We provide the most precise measurement of the WW production cross section in pp collisions to date at a center of mass energy of 1.96 TeV, and set limits on the associated trilinear gauge couplings. The WW -> l nu l(')nu (l, l(')=e, mu) decay channels are analyzed in 1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. The measured cross section is sigma(pp -> WW)=11.5 +/- 2.1(stat+syst)+/- 0.7(lumi) pb. One- and two-dimensional 95% C.L. limits on trilinear gauge couplings are provided.
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| 15. |
- Abazov, M, et al.
(författare)
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Measurement of the Z gamma -> nu(nu)over-bar gamma Production Cross Section and Limits on Anomalous ZZ gamma and Z gamma gamma Couplings in p(p)over-bar Collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:20, s. 201802-
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Tidskriftsartikel (refereegranskat)abstract
- We present the first observation of the Z gamma -> nu(nu) over bar gamma process at the Fermilab Tevatron at 5.1 standard deviations significance, based on 3.6 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron p (p) over bar Collider at root s = 1.96 TeV. The measured Z gamma production cross section multiplied by the branching fraction of Z -> nu(nu) over bar is 32 +/- 9(stat + syst) +/- 2(lumi) fb for the photon E-T > 90 GeV. It is in agreement with the standard model prediction of 39 +/- 4 fb. We set limits on anomalous trilinear Z gamma gamma and ZZ gamma gauge boson couplings, most of which are the most restrictive to date.
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| 16. |
- Abazov, M, et al.
(författare)
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Measurement of trilinear gauge boson couplings from WW plus WZ -> lvjj events in p(p)over-bar collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 80:5, s. 053012-
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Tidskriftsartikel (refereegranskat)abstract
- We present a direct measurement of trilinear gauge boson couplings at gamma WW and ZWW vertices inWW and WZ events produced in p (p) over bar collisions at root s = 1:96 TeV. We consider events with one electron or muon, missing transverse energy, and at least two jets. The data were collected using the D0 detector and correspond to 1:1 fb(-1) of integrated luminosity. Considering two different relations between the couplings at the gamma WW and ZWW vertices, we measure these couplings at 68% C.L. to be kappa(gamma) = 1.07(-0.29)(+0.26) lambda = 0.00(-0.06)(+0.00), and g(1)(Z) = 1.04(-0.09)(+0.09) in a scenario respecting SU(2)(L) circle times U(1)(Y) gauge symmetry and kappa = 1.04(-0.11)(+0.11) and lambda = 0.00(-0.06)(+0.06) in an "equal couplings'' scenario.
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| 17. |
- Abazov, M, et al.
(författare)
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Measurements of differential cross sections of Z/gamma* plus jets plus X events in p(p)over-bar collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 678:1, s. 45-54
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Tidskriftsartikel (refereegranskat)abstract
- We present cross section measurements for Z/gamma* + jets + X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the DO detector at the Fermilab Tevatron p (p) over bar collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb(-1). Leading and next-to-leading order perturbative QCD predictions are compared with the measurements. and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the shapes observed in data. but the predicted normalizations show significant differences with respect to the data, reflecting large scale Uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.
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| 18. |
- Abazov, M, et al.
(författare)
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Observation of Single Top-Quark Production
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:9, s. 092001-
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Tidskriftsartikel (refereegranskat)abstract
- We report observation of the electroweak production of single top quarks in pp collisions at s=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(pp -> tb+X,tqb+X)=3.94 +/- 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5x10(-7), corresponding to a 5.0 standard deviation significance for the observation.
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| 19. |
- Abazov, M, et al.
(författare)
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Relative rates of B meson decays into psi(2S) and J/psi mesons
- 2009
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 79, s. 111102-
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Tidskriftsartikel (refereegranskat)abstract
- We report on a study of the relative rates of B meson decays into psi(2S) and J/psi mesons using 1.3 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe the channels B-s(0) -> psi(2S)phi, B-s(0) -> J/psi phi, B-+/- -> psi(2S)K-+/-, and B-+/- -> J/psi K-+/- and we measure the relative branching fractions for these channels to be B(B-s(0) -> psi(2S)phi)/B(B-s(0) -> J/psi phi)=0.53 +/- 0.10(stat)+/- 0.07(syst)+/- 0.06(B), B(B+ -> psi(2S)K+)/B(B+ -> J/psi K+)=0.63 +/- 0.05(stat)+/- 0.03(syst)+/- 0.07(B), where the final error corresponds to the uncertainty in the J/psi and psi(2S) branching ratio into two muons.
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| 20. |
- Abazov, M, et al.
(författare)
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Search for admixture of scalar top quarks in the t(t)over-bar lepton + jets final state at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 674:1, s. 4-10
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Tidskriftsartikel (refereegranskat)abstract
- A search for pair production of the lightest supersymmetric partner of the top quark, (t) over tilde (1), is performed in the lepton + jets channel using 0.9 fb(-1) of data collected by the D circle divide experiment. Kinematic differences between (t) over tilde (1)(t) over tilde (1) and the dominant top quark pair production background are used to separate the two processes. First limits from Run II of the Fermilab Tevatron Collider for the scalar top quark decaying to a chargino and a b quark ((t) over tilde1 -> (chi) over tilde (+)(1)b) are obtained for scalar top quark masses of 130-190 GeV and chargino masses of 90-150 GeV.
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| 21. |
- Abazov, M, et al.
(författare)
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Search for associated production of charginos and neutralinos in the trilepton final state using 2.3 fb(-1) of data
- 2009
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 680:1, s. 34-43
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Tidskriftsartikel (refereegranskat)abstract
- We report the results of a search for associated production of charginos and neutralinos using a data set corresponding to an integrated luminosity of 2.3 fb(-1) collected with the Demptyset experiment during Run II of the Tevatron proton-antiproton collider. Final states containing three charged leptons and missing transverse energy are probed for a signal from supersymmetry with four dedicated trilepton event selections. No evidence for a signal is observed, and we set limits on the product of production cross section and leptonic branching fraction. Within minimal supergravity, these limits translate into bounds on m(0) and m(1/2) that are well beyond existing limits.
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| 22. |
- Abazov, M, et al.
(författare)
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Search for Charged Higgs Bosons Decaying into Top and Bottom Quarks in pp Collisions
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:19, s. 191802-
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Tidskriftsartikel (refereegranskat)abstract
- We describe a search for production of a charged Higgs boson, qq>-> H+, reconstructed in the tb final state in the mass range 180 <= M-H(+)<= 300 GeV. The search was undertaken at the Fermilab Tevatron collider with a center-of-mass energy s=1.96 TeV and uses 0.9 fb(-1) of data collected with the D0 detector. We find no evidence for charged Higgs boson production and set upper limits on the production cross section in the types I, II, and III two-Higgs-doublet models (2HDMs). An excluded region in the (M-H(+), tan beta) plane for type I 2HDM is presented.
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| 23. |
- Abazov, M, et al.
(författare)
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Search for Dark Photons from Supersymmetric Hidden Valleys
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:8, s. 081802-
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Tidskriftsartikel (refereegranskat)abstract
- We search for a new light gauge boson, a dark photon, with the D0 experiment. In the model we consider, supersymmetric partners are pair produced and cascade to the lightest neutralinos that can decay into the hidden sector state plus either a photon or a dark photon. The dark photon decays through its mixing with a photon into fermion pairs. We therefore investigate a previously unexplored final state that contains a photon, two spatially close leptons, and large missing transverse energy. We do not observe any evidence for dark photons and set a limit on their production.
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| 24. |
- Abazov, M, et al.
(författare)
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Search for Long-Lived Charged Massive Particles with the D0 Detector
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:16, s. 161802-
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Tidskriftsartikel (refereegranskat)abstract
- We search for long-lived charged massive particles using 1.1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron pp Collider. Time-of-flight information is used to search for pair produced long-lived tau sleptons, gauginolike charginos, and Higgsino-like charginos. We find no evidence of a signal and set 95% C.L. cross section upper limits for staus, which vary from 0.31 to 0.04 pb for stau masses between 60 and 300 GeV. We also set lower mass limits of 206 GeV (171 GeV) for pair produced charged gauginos (Higgsinos).
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| 25. |
- Abazov, M, et al.
(författare)
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Search for Next-to-Minimal Supersymmetric Higgs Bosons in the h -> aa ->mu mu mu mu, mu mu tau tau Channels Using pp Collisions at s=1.96 TeV
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:6, s. 061801-
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Tidskriftsartikel (refereegranskat)abstract
- We report on a first search for production of the lightest neutral CP-even Higgs boson (h) in the next-to-minimal supersymmetric standard model, where h decays to a pair of neutral pseudoscalar Higgs bosons (a), using 4.2 fb(-1) of data recorded with the D0 detector at Fermilab. The a bosons are required to either both decay to mu(+)mu(-) or one to mu(+)mu(-) and the other to tau(+)tau(-). No significant signal is observed, and we set limits on its production as functions of M-a and M-h.
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| 26. |
- Abazov, M, et al.
(författare)
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Search for pair production of first-generation leptoquarks in p(p)over-bar collisions at root s=1.96 TeV
- 2009
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 681:3, s. 224-232
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Tidskriftsartikel (refereegranskat)abstract
- A search for pair production of first-generation leptoquarks (LQ) is performed with data collected by the DO experiment in p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron Collider. In a sample of data corresponding to similar to 1 fb(-1) the search has been performed on the final states with two electrons and two jets or one electron, two jets and missing transverse energy. We find our data consistent with standard model expectations. The results are combined with those found in a previous analysis of events with two jets and missing transverse energy to obtain scalar LQ mass limits. We set 95% C.L. lower limits on a scalar LQ mass of 299 GeV. 284 GeV and 216 GeV for beta = 1, beta = 0.5 and beta = 0.02 respectively, where beta is the LQ branching ratio in the eq channel. This improves the results obtained with a lower luminosity sample from Run II of the Tevatron. Lower limits on vector LQ masses with different couplings from 357 GeV to 464 GeV for beta = 0.5 are also set using this analysis.
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| 27. |
- Abazov, M, et al.
(författare)
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Search for Resonant Diphoton Production with the D0 Detector
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:23, s. 231801-
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for a narrow resonance in the inclusive diphoton final state using similar to 2.7 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron p (p) over bar Collider. We observe good agreement between the data and the background prediction, and set the first 95% C. L. upper limits on the production cross section times the branching ratio for decay into a pair of photons for resonance masses between 100 and 150 GeV. This search is also interpreted in the context of several models of electroweak symmetry breaking with a Higgs boson decaying into two photons.
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| 28. |
- Abazov, M, et al.
(författare)
-
Search for Resonant Pair Production of Neutral Long-Lived Particles Decaying to b(b)over-bar in p(p)over-bar Collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:7, s. 071801-
-
Tidskriftsartikel (refereegranskat)abstract
- We report on a first search for resonant pair production of neutral long-lived particles (NLLP) which each decay to a b (b) over bar pair, using 3.6 fb(-1) of data recorded with the D0 detector at the Fermilab Tevatron collider. We search for pairs of displaced vertices in the tracking detector at radii in the range 1.6-20 cm from the beam axis. No significant excess is observed above background, and upper limits are set on the production rate in a hidden-valley benchmark model for a range of Higgs boson masses and NLLP masses and lifetimes.
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| 29. |
- Abazov, M, et al.
(författare)
-
Search for squark production in events with jets, hadronically decaying tau leptons and missing transverse energy at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 680:1, s. 24-33
-
Tidskriftsartikel (refereegranskat)abstract
- A search for supersymmetric partners of quarks is performed in the topology of multijet events accompanied by at least one tau lepton decaying hadronically and large missing transverse energy. Approximately 1 fb(-1) of p (p) over bar collision data from the Fermilab Tevatron Collider at a center of mass energy of 1.96 TeV recorded by the D detector is analyzed. Results are combined with the previously published DO inclusive search for squarks and gluinos. No evidence of physics beyond the Standard Model is found and lower limits on the squark mass up to 410 GeV are derived in the framework of minimal supergravity with tan beta = 15, A(0) = -2m(0) and mu < 0, in the region where decays to tau leptons dominate. Gaugino masses m(1/2) are excluded up to 172 GeV.
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| 30. |
- Abazov, M, et al.
(författare)
-
Search for the lightest scalar top quark in events with two leptons in p(p)over-bar collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 675:3-4, s. 289-296
-
Tidskriftsartikel (refereegranskat)abstract
- We report results of a search for the pair production of the lightest supersymmetric partner of the top quark, (t) over bar (1), using a data set corresponding to an integrated luminosity of 1 fb(-1) collected by the D circle divide detector at a p (p) over bar center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. Both scalar top quarks are assumed to decay into a b quark, a charged lepton and a scalar neutrino. The search is performed in the electron Plus muon and dielectron final states. The signal topology consists of two isolated leptons, missing transverse energy, and jets. We find no evidence for this process and exclude regions of parameter space in the framework of the minimal supersymmetric standard model.
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| 31. |
- Abazov, M, et al.
(författare)
-
Search for the Standard Model Higgs Boson in Tau Final States
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:25, s. 251801-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a search for the standard model Higgs boson using hadronically decaying tau leptons, in 1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp collider. We select two final states: tau(+/-) plus missing transverse energy and b jets, and tau(+)tau(-) plus jets. These final states are sensitive to a combination of associated W/Z boson plus Higgs boson, vector boson fusion, and gluon-gluon fusion production processes. The observed ratio of the combined limit on the Higgs production cross section at the 95% C.L. to the standard model expectation is 29 for a Higgs boson mass of 115 GeV.
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| 32. |
- Abazov, M, et al.
(författare)
-
Search for the Standard Model Higgs Boson in the Missing Energy and Acoplanar b-Jet Topology at root s=1.96 TeV
- 2008
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:25, s. 251802-
-
Tidskriftsartikel (refereegranskat)abstract
- We report a search for the standard model Higgs boson in the missing energy and acoplanar b-jet topology, using an integrated luminosity of 0.93 fb(-1) recorded by the D0 detector at the Fermilab Tevatron p (p) over bar Collider. The analysis includes signal contributions from p (p) over bar -> ZH -> v (v) over barb (b) over bar, as well as from WH production in which the charged lepton from the W boson decay is undetected. Neural networks are used to separate signal from background. In the absence of a signal, we set limits on sigma(p (p) over bar -> VH) x B(H -> b (b) over bar) at the 95% C.L. of 2.6-2.3 pb, for Higgs boson masses in the range 105-135 GeV, where V W, Z. The corresponding expected limits range from 2.8 to 2.0 pb.
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| 33. |
- Abazov, M, et al.
(författare)
-
Search for Third Generation Scalar Leptoquarks Decaying into tau b
- 2008
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:24, s. 241802-:101, s. 241802-
-
Tidskriftsartikel (refereegranskat)abstract
- We have searched for third generation leptoquarks (LQ(3)) using 1.05 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider operating at s=1.96 TeV. We set a 95% C.L. lower limit of 210 GeV on the mass of a scalar LQ(3) state decaying solely to a b quark and a tau lepton.
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| 34. |
- Abazov, V. M., et al.
(författare)
-
A combined search for the standard model Higgs boson at root S=1.96 TeV
- 2008
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 663:1-2, s. 26-36
-
Tidskriftsartikel (refereegranskat)abstract
- We present new results of the search for WH --> lvb (b) over bar production in p (p) over bar collisions at a center-of-mass energy of root S = 1.96 TeV, based on a dataset with integrated luminosity of 0.44 fb(-1). We combine these new results with previously published searches by the DO collaboration, for WH and ZH production analyzed in the E(T)b (b) over bar final state, for ZH (--> l(+)l(-)b (b) over bar) production, for WH (-->. WWW) production, and for H (--> W W) direct production. No signal-like excess is observed either in the W H analysis or in the combination of all D0 Higgs boson analyses. We set 95% C.L. (expected) upper limits on sigma(p (p) over bar --> WH) x B(H --> b (b) over bar) ranging from 1.6 (2.2) ph to 1.9 (3.3) pb for Higgs boson masses between 105 and 145 GeV, to be compared to the theoretical prediction of 0.13 pb for a Standard Model (SM) Higgs boson with mass in m(H) = 115 GeV. After combination with the other DO Higgs boson searches, we obtain for in H = 115 GeV an observed (expected) limit 8.5 (12.1) times higher than the SM predicted Higgs boson production cross section. For m(H) = 160 GeV, the corresponding observed (expected) ratio is 10.2 (9.0).
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| 35. |
- Abazov, V. M., et al.
(författare)
-
b-Jet identification in the D0 experiment
- 2010
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 620:2-3, s. 490-517
-
Tidskriftsartikel (refereegranskat)abstract
- Algorithms distinguishing jets originating from b quarks from other jet flavors are important tools in the physics program of the D0 experiment at the Fermilab Tevatron p (p) over bar collider. This article describes the methods that have been used to identify b-quark jets, exploiting in particular the long lifetimes of b-flavored hadrons, and the calibration of the performance of these algorithms based on collider data.
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| 36. |
- Abazov, V. M., et al.
(författare)
-
Combined D0 measurements constraining the CP-violating phase and width difference in the B-s(0) system
- 2007
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998. ; 76:5, s. 057101-
-
Tidskriftsartikel (refereegranskat)abstract
- We combine the D0 measurement of the width difference between the light and heavy B-s(0) mass eigenstates and of the CP-violating mixing phase determined from the time-dependent angular distributions in the B-s(0)-> J/psi phi decays along with the charge asymmetry in semileptonic decays also measured with the D0 detector. With the additional constraint from the world average of the flavor-specific B-s(0) lifetime, we obtain Delta Gamma(s)equivalent to(Gamma(L)-Gamma(H))=0.13 +/- 0.09 ps(-1) and vertical bar phi(s)vertical bar=0.70(-0.47)(+0.39) or Delta Gamma(s)=-0.13 +/- 0.09 ps(-1) and vertical bar phi(s)vertical bar=2.44(-0.39)(+0.47). The data sample corresponds to an integrated luminosity of 1.1 fb(-1) accumulated with the D0 detector at the Fermilab Tevatron Collider.
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| 37. |
- Abazov, V. M., et al.
(författare)
-
Dependence of the t(t)over-bar production cross section on the transverse momentum of the top quark
- 2010
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:5, s. 515-521
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the differential cross section for t (t) over bar events produced in p (p) over bar collisions at root s = 1.96 TeV as a function of the transverse momentum (p(T)) of the top quark. The selected events contain a high-p(T) lepton (l), a large imbalance in p(T). four or more jets with at least one candidate for a b jet, and correspond to 1 fb(-1) of integrated luminosity recorded with the D0 detector. Objects in the event are associated through a constrained kinematic fit to the t (t) over bar -> WbW (b) over bar -> lvbq (q) over bar' (b) over bar process. Results from next and next-to-next-to-leading-order perturbative QCD calculations agree with the measured differential cross section. Comparisons are also provided to predictions from Monte Carlo event generators using QCD calculations at different levels of precision. (C) 2010 Elsevier B.V. All rights reserved.
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| 38. |
- Abazov, V. M., et al.
(författare)
-
Determination of the strong coupling constant from the inclusive jet cross section in pp collisions at s=1.96 TeV
- 2009
-
Ingår i: PHYS REV D. - 1550-7998 .- 1550-2368. ; 80, s. 111107-
-
Tidskriftsartikel (refereegranskat)abstract
- We determine the strong coupling constant alpha(s) and its energy dependence from the p(T) dependence of the inclusive jet cross section in pp collisions at s=1.96 TeV. The strong coupling constant is determined over the transverse momentum range 50 < p(T)< 145 GeV. Using perturbative QCD calculations to order O(alpha(3)(s)) combined with O(alpha(4)(s)) contributions from threshold corrections, we obtain alpha(s)(M-Z)=0.1161(-0.0048)(+0.0041). This is the most precise result obtained at a hadron-hadron collider.
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| 39. |
- Abazov, V. M., et al.
(författare)
-
Direct observation of the strange b baryon Xi(-)(b)
- 2007
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 99:5, s. 052001-
-
Tidskriftsartikel (refereegranskat)abstract
- We report the first direct observation of the strange b baryon Xi(-)(b)(Xi) over bar (+)(b)). We reconstruct the decay Xi(-)(b)-->J/psi Xi(-), with J/psi-->mu(+)mu(-), and Xi(-)-->Lambda pi(-)-->p pi(-)pi(-) in p (p) over bar collisions at root s = 1.96 TeV. Using 1.3 fb(-1) of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat)(-0.4)(+1.9)(syst) Xi(-)(b) candidates at a mass of 5.774 +/- 0.011(stat) +/- 0.015(syst) GeV. The significance of the observed signal is 5.5 sigma, equivalent to a probability of 3.3 x 10(-8) of it arising from a background fluctuation. Normalizing to the decay Lambda(b)-->J/psi Lambda, we measure the relative rate sigma(Xi(-)(b))xB(Xi(-)(b)-->J/psi Xi)/ sigma(Lambda(b))xB(Lambda(b)-->J/psi Lambda) = 0.28 +/- 0.09(stat)(-0.08)(+0.09)(syst).
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| 40. |
- Abazov, V. M., et al.
(författare)
-
Double parton interactions in gamma+3 jet events in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 81:5, s. 052012-
-
Tidskriftsartikel (refereegranskat)abstract
- We have used a sample of gamma + 3 jets events collected by the D0 experiment with an integrated luminosity of about 1 fb(-1) to determine the fraction of events with double parton scattering (f(DP)) in a single p (p) over bar collision at root s = 1.96 TeV. The DP fraction and effective cross section (sigma(eff)), a process-independent scale parameter related to the parton density inside the nucleon, are measured in three intervals of the second (ordered in p(T)) jet transverse momentum p(T)(jet2) within the range 15 <= p(T)(jet2) <= 30 GeV. In this range, f(DP) varies between 0.23 <= f(DP) <= 0.47, while sigma(eff) has the average value sigma(ave)(eff) = 16.4 +/- 0.3(stat) +/- 2.3(syst) mb.
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| 41. |
- Abazov, V. M., et al.
(författare)
-
Evidence for production of single top quarks
- 2008
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; D:78, s. 012005-
-
Forskningsöversikt (refereegranskat)abstract
- We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p (p) over bar collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top-quark partner that is always produced from strong-coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top-quark production has been searched for in ever larger data sets. In this analysis, we select events from a 0.9 fb(-1) data set that have an electron or muon and missing transverse energy from the decay of a W boson from the top-quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W + jets and t (t) over bar events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix-element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top-quark production of sigma(p (p) over bar -> tb + X, tqb + X) = 4.7 +/- 1.3 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top-quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find vertical bar V(tb)f(1)(L)vertical bar = 1.31(-0.21)(+0.25), where f(1)(L) is a generic vector coupling. This model-independent measurement translates into 0.68 <= 1 at the 95% C.L. in the standard model.
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| 42. |
- Abazov, V. M., et al.
(författare)
-
Evidence for production of single top quarks and first direct measurement of vertical bar V-tb vertical bar
- 2007
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 98:18, s. 181802-
-
Tidskriftsartikel (refereegranskat)abstract
- The D0 Collaboration presents first evidence for the production of single top quarks at the Fermilab Tevatron < p(p)over bar > collider. Using a 0.9 fb(-1) dataset, we apply a multivariate analysis to separate signal from background and measure sigma(< p(p)over bar >-> tb+X,tqb+X)=4.9 +/- 1.4 pb. The probability to measure a cross section at this value or higher in the absence of a signal is 0.035%, corresponding to a 3.4 standard deviation significance. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa matrix element that describes the Wtb coupling and find 0.68 <= 1 at 95% C.L. within the standard model.
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| 43. |
- Abazov, V. M., et al.
(författare)
-
Experimental discrimination between charge 2e/3 top quark and charge 4e/3 exotic quark production scenarios
- 2007
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 98:4, s. 041801-
-
Tidskriftsartikel (refereegranskat)abstract
- We present the first experimental discrimination between the 2e/3 and 4e/3 top quark electric charge scenarios, using top quark pairs (t (t) over bar) produced in p (p) over bar collisions at root s =1.96 TeV by the Fermilab Tevatron Collider. We use 370 pb(-1) of data collected by the D0 experiment and select events with at least one high transverse momentum electron or muon, high transverse energy imbalance, and four or more jets. We discriminate between b- and (b) over bar -quark jets by using the charge and momenta of tracks within the jet cones. The data are consistent with the expected electric charge, |q|=2e/3. We exclude, at the 92% C.L., that the sample is solely due to the production of exotic quark pairs Q (Q) over bar with |q|=4e/3. We place an upper limit on the fraction of Q (Q) over bar pairs rho < 0.80 at the 90% C.L.
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| 44. |
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| 45. |
- Abazov, V. M., et al.
(författare)
-
Lifetime difference and CP-violating phase in the B-s(0) system
- 2007
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 98:12, s. 121801-
-
Tidskriftsartikel (refereegranskat)abstract
- From an analysis of the decay B-s(0)-> J/psi phi, we obtain the width difference between the light and heavy mass eigenstates Delta Gamma equivalent to(Gamma(L)-Gamma(H))=0.17 +/- 0.09(stat)+/- 0.02(syst) ps(-1) and the CP-violating phase phi(s)=-0.79 +/- 0.56(stat)(-0.01)(+0.14)(syst). Under the hypothesis of no CP violation (phi(s)equivalent to 0), we obtain 1/Gamma=tau/(B-s(0))=1.52 +/- 0.08(stat)(-0.03)(+0.01)(syst) ps and Delta Gamma=0.12(-0.10)(+0.08)(stat)+/- 0.02(syst) ps(-1). The data sample corresponds to an integrated luminosity of about 1.1 fb(-1) accumulated with the D0 detector at the Fermilab Tevatron collider. This is the first direct measurement of the CP-violating mixing phase in the B-s(0) system.
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| 46. |
- Abazov, V. M., et al.
(författare)
-
Limits on anomalous trilinear gauge couplings from WW -> e(+)e(-), WW -> e(+/-)mu(-/+), and WW ->mu(+)mu(-) events from pp collisions at root s=1.96 TeV
- 2006
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 74:5, s. 057101-
-
Tidskriftsartikel (refereegranskat)abstract
- Limits are set on anomalous WW gamma and WWZ trilinear gauge couplings using W+W--> e(+)nu(e)e(-)(nu) over bar (e), W+W--> e(+/-)nu(e)mu(-/+)nu(mu), and W+W-->mu(+)nu(mu)mu(-)(nu) over bar (mu) events. The data set was collected by the Run II D0 detector at the Fermilab Tevatron Collider and corresponds to approximately 250 pb(-1) of integrated luminosity at root s=1.96 TeV. Under the assumption that the WW gamma couplings are equal to the WWZ couplings and using a form factor scale of Lambda=2.0 TeV, the combined 95% C.L. one-dimensional coupling limits from all three channels are -0.32
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| 47. |
- Abazov, V. M., et al.
(författare)
-
Measurement of B-d mixing using opposite-side flavor tagging
- 2006
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 74:11, s. 112002-
-
Tidskriftsartikel (refereegranskat)abstract
- We report on a measurement of the B-d(0) mixing frequency and the calibration of an opposite-side flavor tagger in the D0 experiment. Various properties associated with the b quark on the opposite side of the reconstructed B meson are combined using a likelihood-ratio method into a single variable with enhanced tagging power. Its performance is tested with data, using a large sample of reconstructed semileptonic B ->mu(DX)-X-0 and B ->mu(DX)-X-* decays, corresponding to an integrated luminosity of approximately 1 fb(-1). The events are divided into groups depending on the value of the combined tagging variable, and an independent analysis is performed in each group. Combining the results of these analyses, the overall effective tagging power is found to be epsilon D-2=(2.48 +/- 0.21(-0.06)(+0.08))%. The measured B-d(0) mixing frequency Delta m(d)=0.506 +/- 0.020(stat)+/- 0.016(syst) ps(-1) is in good agreement with the world average value.
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| 48. |
- Abazov, V. M., et al.
(författare)
-
Measurement of beta (t -> Wb)/beta(t -> Wq) at root s=1.96 TeV
- 2006
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 639:6, s. 616-622
-
Tidskriftsartikel (refereegranskat)abstract
- We present the measurement of R = B(t -> Wb)/B(t -> Wq) in pp collisions at root s = 1.96 TeV, using 230 pb(-1) of data collected by the DO experiment at the Fermilab Tevatron Collider. We fit simultaneously R and the number (N-tt) of selected top quark pairs (tt), to the number of identified b-quark jets in events with one electron or one muon, three or more jets, and high transverse energy imbalance. To improve sensitivity, kinematical properties of events with no identified b-quark jets are included in the fit. We measure R = 1.03(-0.17)(0.19) (stat + syst), in good agreement with the standard model. We set lower limits of R > 0.61 and vertical bar V-tb vertical bar > 0.78 at 95% confidence level.
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| 49. |
- Abazov, V. M., et al.
(författare)
-
Measurement of sigma(p(p)over-bar -> Z plus X)Br(Z -> tau(+)tau(-)) at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 670:4-5, s. 292-299
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the cross section for Z boson production times the branching fraction to tau lepton pairs sigma(p (p) over bar -> Z + X)Br(Z -> tau(+)tau(-)) in p (p) over bar collisions at root s = 1.96 TeV. The measurement is performed in the channel in which one tau lepton decays into a muon and neutrinos. and the other tau lepton decays hadronically or into an electron and neutrinos. The data sample corresponds to an integrated luminosity of 1.0 fb(-1) collected with the DO detector at the Fermilab Tevatron Collider. The sample contains 1511 candidate events with an estimated 20% background from jets or muons misidentified as tau leptons. We obtain sigma . Br = 240 +/- 8 (star) +/- 12 (sys) +/- 15 (lum) pb, which is consistent with the standard model prediction.
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| 50. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the Angular and Lifetime Parameters of the Decays B-d(0) -> J/psi K*(0) and B-s(0) -> J/psi phi
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:3, s. 032001-:102, s. 032001-
-
Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the linear polarization amplitudes and the strong relative phases that describe the flavor-untagged decays B-d(0) --> J/psi K*(0) and B-s(0) --> J/psi phi in the transversity basis. We also measure the mean lifetime (tau) over bar (s) of the B-s(0) mass eigenstates and the lifetime ratio (tau) over bar (s)/tau(d). The analyses are based on approximately 2.8 fb(-1) of data recorded with the D0 detector. From our measurements of the angular parameters we conclude that there is no evidence for a deviation from flavor SU( 3) symmetry for these decays and that the factorization assumption is not valid for the B-d(0) --> J/psi K*(0) decay.
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