| 1. |
- Aaltonen, T., et al.
(author)
-
Combination of Tevatron Searches for the Standard Model Higgs Boson in the W+W- Decay Mode
- 2010
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061802-
-
Journal article (peer-reviewed)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.
|
|
| 2. |
- Abazov, V. M., et al.
(author)
-
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
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 82:1, s. 012003-
-
Journal article (peer-reviewed)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.
|
|
| 3. |
- Abazov, V. M., et al.
(author)
-
Measurement of spin correlation in t(t)over-bar production using dilepton final states
- 2011
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 702:1, s. 16-23
-
Journal article (peer-reviewed)abstract
- We measure the correlation between the spin of the top quark and the spin of the anti-top quark in t (t) over bar -> W(+)bW(-)(b) over bar -> l(+)vbl(-) (v) over bar(b) over bar final states produced in p (p) over bar collisions at a center of mass energy root s = 1.96 TeV, where l is an electron or muon. The data correspond to an integrated luminosity of 5.4 fb(-1) and were collected with the D0 detector at the Fermilab Tevatron collider. The correlation is extracted from the angles of the two leptons in the t and (t) over bar rest frames, yielding a correlation strength C = 0.10(-0.45)(+0.45). in agreement with the NLO QCD prediction within two standard deviations, but also in agreement with the no correlation hypothesis.
|
|
| 4. |
- Abazov, V. M., et al.
(author)
-
Search for flavor changing neutral currents in decays of top quarks
- 2011
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 701:3, s. 313-320
-
Journal article (peer-reviewed)abstract
- We present a search for flavor changing neutral currents in decays of top quarks. The analysis is based on a search for (ℓ,ℓ′=e,μ) final states using 4.1 fb−1 of integrated luminosity of collisions at . We extract limits on the branching ratio B(t→Zq) (q=u,c quarks), assuming anomalous tuZ or tcZ couplings. We do not observe any sign of such anomalous coupling and set a limit of B<3.2% at 95% C.L.
|
|
| 5. |
- Abazov, V. M., et al.
(author)
-
Search for neutral Higgs bosons in the multi-b-jet topology in 5.2 fb(-1) of p(p)over-bar collisions at root s=1.96 TeV
- 2011
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 698:2, s. 97-104
-
Journal article (peer-reviewed)abstract
- Data recorded by the DO experiment at the Fermilab Tevatron Collider are analyzed to search for neutral Higgs bosons produced in association with b quarks. The search is performed in the three-b-quark channel using multijet-triggered events corresponding to an integrated luminosity of 5.2 fb(-1). In the absence of any significant excess above background, limits are set on the cross section multiplied by the branching ratio in the Higgs boson mass range 90 to 300 GeV, extending the excluded regions in the parameter space of the minimal supersymmetric standard model. (C) 2011 Elsevier B.V. All rights reserved.
|
|
| 6. |
- Abazov, V. M., et al.
(author)
-
Search for W' -> tb resonances with left- and right-handed couplings to fermions D0 Collaboration
- 2011
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 699:3, s. 145-150
-
Journal article (peer-reviewed)abstract
- We present a search for the production of a heavy gauge boson, W', that decays to third-generation quarks, by DO Collaboration in p (p) over bar) collisions at root s = 1.96 TeV. We set 95% confidence level upper limits on the production cross section times branching fraction. For the first time, we set limits for arbitrary combinations of left-and right-handed couplings of the W' boson to fermions. For couplings with the same strength as for the standard model W boson, we set the following limits, assuming that there are right-handed neutrinos nu(R) for all three generations with M(W') > m(nu(R)): M(W') > 863 GeV for purely left-handed couplings, M(W') > 885 GeV for purely right-handed couplings, and M(W') > 916 GeV if both left-and right-handed couplings are present. The limit for right-handed couplings improves for M(W') < m(nu(R)) to M(W') > 890 GeV.
|
|
| 7. |
- Abazov, V. M., et al.
(author)
-
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
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 83:5, s. 052008-
-
Journal article (peer-reviewed)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).
|
|
| 8. |
- Abazov, V. M., et al.
(author)
-
b-Jet identification in the D0 experiment
- 2010
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 620:2-3, s. 490-517
-
Journal article (peer-reviewed)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.
|
|
| 9. |
- Abazov, V. M., et al.
(author)
-
Measurement of color flow in t(t)over-bar events from p(p)over-bar collisions at root s=1.96 TeV
- 2011
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998. ; 83:9, s. 092002-
-
Journal article (peer-reviewed)abstract
- We present the first measurement of the color representation of the hadronically decaying W boson in t (t) over bar events, from 5.3 fb(-1) of integrated luminosity collected with the D0 experiment. A novel calorimeter-based vectorial variable, "jet pull," is used, sensitive to the color-flow structure of the final state. We find that the fraction of uncolored W bosons is 0.56 +/- 0.42(stat + syst), in agreement with the standard model.
|
|
| 10. |
- Abazov, V. M., et al.
(author)
-
Measurement of the ratio of inclusive cross sections sigma(p(p)over-bar -> Z plus b-quark jet)/sigma(p(p)over-bar -> Z plus jet) at root s=1.96 TeV
- 2011
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998. ; 83:3, s. 031105-
-
Journal article (peer-reviewed)abstract
- The ratio of the cross section for p (p) over bar interactions producing a Z boson and at least one b-quark jet to the inclusive Z + jet cross section is measured using 4.2 fb(-1) of p (p) over bar collisions collected with the D0 detector at the Fermilab Tevatron collider at root s = 1.96 TeV. The Z -> l(+) l- candidate events with at least one b jet are discriminated from Z + charm and light jet(s) events by a novel technique that exploits the properties of the tracks associated to the jet. The measured ratio is 0: 0193 +/- 0: 0027 for events having a jet with transverse momentum p(T) > 20 GeV and pseudorapidity vertical bar eta vertical bar <= 2.5, which is the most precise to date and is consistent with theoretical predictions.
|
|
