| 51. |
- Abazov, V. M., et al.
(författare)
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Search for associated Higgs boson production WH -> WWW*-> l(+/-)nu l('+/-)nu(')+X in p(p)over-bar collisions at root S=1.96 TeV
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:15, s. 151804-
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for associated Higgs boson production in the process p (p) over bar -> WH -> WWW*-> l(+/-)nu l('+/-)nu(')+X in final states containing two like-sign isolated electrons or muons (e(+/-)e(+/-), e(+/-)mu(+/-), or mu(+/-)mu(+/-)). The search is based on D0 run II data samples corresponding to integrated luminosities of 360-380 pb(-1). No excess is observed over the predicted standard model background. We set 95% C.L. upper limits on sigma ->(p (p) over bar WH) x Br(H -> WW*) between 3.2 and 2.8 pb for Higgs boson masses from 115 to 175 GeV.
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| 52. |
- Abazov, V. M., et al.
(författare)
-
Search for flavor-changing-neutral-current D meson decays
- 2008
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 100:10, s. 101801-:100, s. 101801-
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Tidskriftsartikel (refereegranskat)abstract
- We study the flavor-changing-neutral-current process c -> u mu(+)mu(-) 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 see clear indications of the charged-current mediated D-s(+) and D+->phi pi(+)->mu(+)mu(-)pi(+) final states with significance greater than 4 standard deviations above background for the D+ state. We search for the continuum neutral-current decay of D+->pi(+)mu(+)mu(-) in the dimuon invariant mass spectrum away from the phi resonance. We see no evidence of signal above background and set a limit of B(D+->pi(+)mu(+)mu(-))< 3.9 x 10(-6) at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c -> u mu(+)mu(-) transition.
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| 53. |
- Abazov, V. M., et al.
(författare)
-
Search for neutral Higgs bosons decaying to tau pairs in p(p)over-bar collisions at root s=1.96 TeV
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:12, s. 121802-
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Tidskriftsartikel (refereegranskat)abstract
- A search for the production of neutral Higgs bosons Phi decaying into tau(+)tau(-) final states in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV is presented. The data, corresponding to an integrated luminosity of approximately 325 pb(-1), were collected by the D0 experiment at the Fermilab Tevatron Collider. Since no excess compared to the expectation from standard model processes is found, limits on the production cross section times branching ratio are set. The results are combined with those obtained from the D0 search for Phi b((b) over bar)-> b (b) over barb((b) over bar) and are interpreted in the minimal supersymmetric standard model.
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| 54. |
- Abazov, V. M., et al.
(författare)
-
Search for neutral, long-lived particles decaying into two muons in p(p)over-bar collisions at root s=1.96 TeV
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:16, s. 161802-
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for a neutral particle, pair produced in pp collisions at root s=1.96 TeV, which decays into two muons and lives long enough to travel at least 5 cm before decaying. The analysis uses approximate to 380 pb(-1) of data recorded with the D0 detector. The background is estimated to be about one event. No candidates are observed, and limits are set on the pair-production cross section times branching fraction into dimuons + X for such particles. For a mass of 10 GeV and lifetime of 4x10(-11) s, we exclude values greater than 0.14 pb (95% C.L.). These results are used to limit the interpretation of NuTeV's excess of dimuon events.
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| 55. |
- Abazov, V. M., et al.
(författare)
-
Search for pair production of scalar bottom quarks in p(p)over-bar collisions at root s = 1.96 TeV
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:17, s. 171806-
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Tidskriftsartikel (refereegranskat)abstract
- A search for direct production of scalar bottom quarks ((b) over bar) is performed with 310 pb(-1) of data collected by the D0 experiment in p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron Collider. The topology analyzed consists of two b jets and an imbalance in transverse momentum due to undetected neutralinos (chi(0)(1)), with chi(0)(1) assumed to be the lightest supersymmetric particle. We find the data consistent with standard model expectations, and set a 95% C.L. exclusion domain in the (m(b), m(chi 1)(0)) mass plane, improving significantly upon the results from run I of the Tevatron.
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| 56. |
- Abazov, V. M., et al.
(författare)
-
Search for particles decaying into a Z boson and a photon in p(p)over-bar collisions at root s=1.96 TeV
- 2006
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 641:6, s. 415-422
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of a search for a new particle X produced in p (p) over bar collisions at root s- = 1.96 TeV and subsequently decaying to Z gamma. The search uses 0.3 fb(-1) of data collected with the DO detector at the Fermilab Tevatron Collider. We set limits on the production cross section times the branching fraction sigma(p (p) over bar -> X) x B(X -> Z gamma) that range from 0.4 to 3.5 pb at the 95% C.L. for X with invariant masses between 100 and 1000 GeV/c(2), over a wide range of X decay widths.
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| 57. |
- Abazov, V. M., et al.
(författare)
-
Search for production of single top quarks via tcg and tug flavor-changing-neutral-current couplings
- 2007
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 99:19, s. 191802-
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Tidskriftsartikel (refereegranskat)abstract
- We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb(-1) of lepton+jets data from p (p) over tilde collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters kappa(c)(g)/Lambda and kappa(u)(g)/Lambda, where kappa(g) define the strength of tcg and tug couplings, and Lambda defines the scale of new physics. The limits at 95% C.L. are kappa(c)(g)/Lambda < 0.15 TeV-1 and kappa(u)(g)/Lambda < 0.037 TeV-1.
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| 58. |
- Abazov, V. M., et al.
(författare)
-
Search for R-parity violating supersymmetry via the LL(E)over-bar couplings lambda(121), lambda(122) or lambda(133) in p(p)over-bar collisions at root s=1.96 TeV
- 2006
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 638:5-6, s. 441-449
-
Tidskriftsartikel (refereegranskat)abstract
- A search for gaugino pair production with a trilepton signature in the framework of R-parity violating supersymmetry via the couplings; lambda(121), lambda(122), or lambda(133) is presented. The data, corresponding to an integrated luminosity of L approximate to 360 pb(-1), were collected from April 2002 to August 2004 with the D0 detector at the Fermilab Tevatron Collider, at a center-of-mass energy of root s = 1.96 TeV. This analysis considers final states with three charged leptons with the flavor combinations eel, mu mu l, and ee tau (l = e or mu). No evidence for supersymmetry is found and limits at the 95% confidence level are set on the gaugino pair production cross section and lower bounds on the masses of the lightest neutralino and chargino are derived in two supersymmetric models.
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| 59. |
- Abazov, V. M., et al.
(författare)
-
Search for resonant second generation slepton production at the Fermilab Tevatron
- 2006
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:11, s. 111801-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a search for supersymmetry in the R-parity violating resonant production and decay of smuons and muon sneutrinos in the channels mu ->chi(0)(1)mu, mu ->chi(0)(2,3,4)mu, and nu(mu)->chi(+/-)(1,2)mu. We analyzed 0.38 fb(-1) of integrated luminosity collected between April 2002 and August 2004 with the D0 detector at the Fermilab Tevatron Collider. The observed number of events is in agreement with the standard model expectation, and we calculate 95% C.L. limits on the slepton production cross section times branching fraction to gaugino plus muon, as a function of slepton and gaugino masses. In the framework of minimal supergravity, we set limits on the coupling parameter lambda(')(211), extending significantly previous results obtained in Run I of the Tevatron and at the CERN LEP collider.
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| 60. |
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