| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- 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.
|
|
| 7. |
- Mishra, A., et al.
(author)
-
Stroke genetics informs drug discovery and risk prediction across ancestries
- 2022
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 611, s. 115-123
-
Journal article (peer-reviewed)abstract
- Previous genome-wide association studies (GWASs) of stroke - the second leading cause of death worldwide - were conducted predominantly in populations of European ancestry(1,2). Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis(3), and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach(4), we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry(5). Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries.
|
|
| 8. |
|
|
| 9. |
- Abazov, V. M., et al.
(author)
-
Search for large extra dimensions via single photon plus missing energy final states at root s=1.96 TeV
- 2008
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:1, s. 011601-:101, s. 011601-
-
Journal article (peer-reviewed)abstract
- We report on a search for large extra dimensions in a data sample of approximately 1 fb(-1) of p (p) over bar collisions at root s=1.96 TeV. We investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. we set limits on the fundamental mass scale M-D from 884 to 778 GeV for two to eight extra dimensions.
|
|
| 10. |
- Abazov, V. M., et al.
(author)
-
Evidence for the Decay B-s(0)->(DsDs(*))-D-(*) and a Measurement of Delta Gamma(CP)(s)/Gamma(s)
- 2009
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:9, s. 091801-
-
Journal article (peer-reviewed)abstract
- We search for the semi-inclusive process B-s(0)->(DsDs(*))-D-(*) using 2.8 fb(-1) of pp collisions at s=1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe 26.6 +/- 8.4 signal events with a significance above background of 3.2 standard deviations yielding a branching ratio of B(B-s(0)->(DsDs(*))-D-(*))=0.035 +/- 0.010(stat.)+/- 0.011(syst.). Under certain theoretical assumptions, these double-charm final states saturate CP-even eigenstates in the B-s(0) decays resulting in a width difference of Delta Gamma(CP)(s)/Gamma(s)=0.072 +/- 0.021(stat.)+/- 0.022(syst.).
|
|
| 11. |
- Abazov, V. M., et al.
(author)
-
Measurement of sigma(p(p)over-bar -> Z plus X)Br(Z -> tau(+)tau(-)) at root s=1.96 TeV
- 2009
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 670:4-5, s. 292-299
-
Journal article (peer-reviewed)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.
|
|
| 12. |
- Abazov, V. M., et al.
(author)
-
Measurement of the dijet invariant mass cross section in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:5, s. 531-538
-
Journal article (peer-reviewed)abstract
- The inclusive dijet production double differential cross section as a function of the dijet invariant mass and of the largest absolute rapidity of the two jets with the largest transverse momentum in an event is measured in p (p) over bar collisions at root s = 1.96 TeV using 0.7 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The measurement is performed in six rapidity regions up to a maximum rapidity of 2.4. Next-to-leading order perturbative QCD predictions are found to be in agreement with the data. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 13. |
- Abazov, V. M., et al.
(author)
-
Search for Anomalous Top-Quark Couplings with the D0 Detector
- 2009
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:9, s. 092002-
-
Journal article (peer-reviewed)abstract
- Anomalous Wtb couplings modify the angular correlations of the top-quark decay products and change the single top-quark production cross section. We present limits on anomalous top-quark couplings by combining information from W boson helicity measurements in top-quark decays and anomalous coupling searches in the single top-quark final state. We set limits on right-handed vector couplings as well as left-handed and right-handed tensor couplings based on about 1 fb(-1) of data collected by the D0 experiment.
|
|
| 14. |
- Abazov, V. M., et al.
(author)
-
Search for Neutral Higgs Bosons at High tan beta in the b(h/H/A) -> b tau(+)tau(-) Channel
- 2009
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 051804-:102, s. 051804-
-
Journal article (peer-reviewed)abstract
- The first search in p (p) over bar collisions at root s = 1.96 TeV for the production of neutral Higgs bosons in association with bottom quarks and decaying in two tau leptons is presented. The cross section for this process is enhanced in many extensions of the standard model, such as its minimal supersymmetric extension (MSSM) at large tan beta. The data, corresponding to an integrated luminosity of 328 pb(-1), were collected with the D0 detector at the Fermilab Tevatron Collider. An upper limit is set on the production cross section of neutral Higgs bosons in the mass range of 90 to 150 GeV, and this limit is used to exclude part of the MSSM parameter space.
|
|
| 15. |
- Abazov, V. M., et al.
(author)
-
Search for pair production of second generation scalar leptoquarks
- 2009
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 671:2, s. 224-232
-
Journal article (peer-reviewed)abstract
- We report on a search for the pair production of second generation scalar leptoquarks (LQ) in p (p) over bar collisions at the center of mass energy root s- = 1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb(-1) collected with the D empty set experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ (LQ) over bar -> mu q nu q and LQ (LQ) over bar -> mu q mu q decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction beta for the decay LQ -> mu q. These are interpreted as lower limits on the leptoquark mass as a function of beta. For beta = 1 (0.5), scalar second generation leptoquarks with masses up to 316 GeV (270 GeV) are excluded.
|
|
| 16. |
- Blokland, G. A. M., et al.
(author)
-
Sex-Dependent Shared and Nonshared Genetic Architecture Across Mood and Psychotic Disorders
- 2022
-
In: Biological Psychiatry. - : Elsevier BV. - 0006-3223 .- 1873-2402. ; 91:1, s. 102-117
-
Journal article (peer-reviewed)abstract
- Background: Sex differences in incidence and/or presentation of schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BIP) are pervasive. Previous evidence for shared genetic risk and sex differences in brain abnormalities across disorders suggest possible shared sex-dependent genetic risk. Methods: We conducted the largest to date genome-wide genotype-by-sex (G×S) interaction of risk for these disorders using 85,735 cases (33,403 SCZ, 19,924 BIP, and 32,408 MDD) and 109,946 controls from the PGC (Psychiatric Genomics Consortium) and iPSYCH. Results: Across disorders, genome-wide significant single nucleotide polymorphism–by-sex interaction was detected for a locus encompassing NKAIN2 (rs117780815, p = 3.2 × 10−8), which interacts with sodium/potassium-transporting ATPase (adenosine triphosphatase) enzymes, implicating neuronal excitability. Three additional loci showed evidence (p < 1 × 10−6) for cross-disorder G×S interaction (rs7302529, p = 1.6 × 10−7; rs73033497, p = 8.8 × 10−7; rs7914279, p = 6.4 × 10−7), implicating various functions. Gene-based analyses identified G×S interaction across disorders (p = 8.97 × 10−7) with transcriptional inhibitor SLTM. Most significant in SCZ was a MOCOS gene locus (rs11665282, p = 1.5 × 10−7), implicating vascular endothelial cells. Secondary analysis of the PGC-SCZ dataset detected an interaction (rs13265509, p = 1.1 × 10−7) in a locus containing IDO2, a kynurenine pathway enzyme with immunoregulatory functions implicated in SCZ, BIP, and MDD. Pathway enrichment analysis detected significant G×S interaction of genes regulating vascular endothelial growth factor receptor signaling in MDD (false discovery rate-corrected p < .05). Conclusions: In the largest genome-wide G×S analysis of mood and psychotic disorders to date, there was substantial genetic overlap between the sexes. However, significant sex-dependent effects were enriched for genes related to neuronal development and immune and vascular functions across and within SCZ, BIP, and MDD at the variant, gene, and pathway levels. © 2021 Society of Biological Psychiatry
|
|
| 17. |
- Abazov, V. M., et al.
(author)
-
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
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:3, s. 032001-:102, s. 032001-
-
Journal article (peer-reviewed)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.
|
|
| 18. |
- Abazov, V. M., et al.
(author)
-
Observation of ZZ Production in p(p)over-bar Collisions at root s=1.96 TeV
- 2008
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:17, s. 171803-:101, s. 171803-
-
Journal article (peer-reviewed)abstract
- We present an observation for ZZ -> l(+) l(-) l'(+) l'(-) (l, l' =e or mu) production in p (p) over bar collisions at a center-of-mass energy of root s = 1.96 TeV. Using 1.7 fb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider, we observe three candidate events with an expected background of 0.14(-0.02)(+0.03) events. The significance of this observation is 5.3 standard deviations. The combination of D0 results in this channel, as well as in ZZ -> l(+) l(-) v (v) over bar yields a significance of 5.7 standard deviations and a combined cross section of sigma(ZZ) = 1.60 +/- 0.63(stat)(-0.17)(+0.16)(syst) pb.
|
|
| 19. |
- Abazov, V. M., et al.
(author)
-
Search for Associated W and Higgs Boson Production in p(p)over-bar Collisions at root s=1.96 TeV
- 2009
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 051803-:102, s. 051803-
-
Journal article (peer-reviewed)abstract
- We present results of a search for WH -> l nu b (b) over bar production in p (p) over bar collisions based on the analysis of 1.05 fb(-1) of data collected by the D0 experiment at the Fermilab Tevatron, using a neural network for separating the signal from backgrounds. No signal-like excess is observed, and we set 95% C. L. upper limits on the WH production cross section multiplied by the branching ratio for H -> b (b) over bar for Higgs boson masses between 100 and 150 GeV. For a mass of 115 GeV, we obtain an observed (expected) limit of 1.5 (1.4) pb, a factor of 11.4 (10.7) times larger than the standard model prediction.
|
|
| 20. |
- Abazov, V. M., et al.
(author)
-
Search for Large Extra Spatial Dimensions in the Dielectron and Diphoton Channels in p(p)over-bar Collisions at root s=1.96 TeV
- 2009
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 051601-:102, s. 051601-
-
Journal article (peer-reviewed)abstract
- We report on a search for large extra spatial dimensions in the dielectron and diphoton channels using a data sample of 1: 05 fb(-1) of p (p) over bar collisions at a center-of-mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. The invariant mass spectrum of the data agrees well with the prediction of the standard model. We find the most restrictive 95% C. L. lower limits on the effective Planck scale between 2.1 and 1.3 TeV for 2 to 7 extra dimensions.
|
|
| 21. |
- Abazov, V. M., et al.
(author)
-
Dependence of the t(t)over-bar production cross section on the transverse momentum of the top quark
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:5, s. 515-521
-
Journal article (peer-reviewed)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.
|
|
| 22. |
- Abazov, M, et al.
(author)
-
A novel method for modeling the recoil in W boson events at hadron colliders
- 2009
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 609:2-3, s. 250-262
-
Journal article (peer-reviewed)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.
|
|
| 23. |
- Abazov, V. M., et al.
(author)
-
Determination of the strong coupling constant from the inclusive jet cross section in pp collisions at s=1.96 TeV
- 2009
-
In: PHYS REV D. - 1550-7998 .- 1550-2368. ; 80, s. 111107-
-
Journal article (peer-reviewed)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.
|
|
| 24. |
- Abazov, V. M., et al.
(author)
-
Measurement of the t(t)over-bar cross section using high-multiplicity jet events
- 2010
-
In: Physical Review D. - 1550-7998 .- 1550-2368. ; 82, s. 032002-
-
Journal article (peer-reviewed)abstract
- We present a measurement of the t (t) over bar cross section using high-multiplicity jet events produced in p (p) over bar collisions at root s = 1.96 TeV. These data were recorded at the Fermilab Tevatron Collider with the D0 detector. Events with at least six jets, two of them identified as b jets, were selected from a 1 fb(-1) data set. The measured cross section, assuming a top quark mass of 175 GeV/c(2), is 6.9 +/- 2.0 pb, in agreement with theoretical expectations.
|
|
| 25. |
- Abazov, V. M., et al.
(author)
-
Measurement of the top quark mass in final states with two leptons
- 2009
-
In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 80, s. 092006-
-
Journal article (peer-reviewed)abstract
- We present measurements of the top quark mass (m(t)) in tt candidate events with two final state leptons using 1 fb(-1) of data collected by the D0 experiment. Our data sample is selected by requiring two fully identified leptons or by relaxing one lepton requirement to an isolated track if at least one jet is tagged as a b jet. The top quark mass is extracted after reconstructing the event kinematics under the tt hypothesis using two methods. In the first method, we integrate over expected neutrino rapidity distributions, and in the second we calculate a weight for the possible top quark masses based on the observed particle momenta and the known parton distribution functions. We analyze 83 candidate events in the data and obtain m(t)=176.2 +/- 4.8(stat)+/- 2.1(sys) GeV and m(t)=173.2 +/- 4.9(stat)+/- 2.0(sys) GeV for the two methods, respectively. Accounting for correlations between the two methods, we combine the measurements to obtain m(t)=174.7 +/- 4.4(stat)+/- 2.0(sys) GeV.
|
|
| 26. |
- Abazov, V. M., et al.
(author)
-
Measurement of the WZ -> lvll cross section and limits on anomalous triple gauge couplings in p(p)over-bar collisions at root s=1.96 TeV
- 2011
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 695:1-4, s. 67-73
-
Journal article (peer-reviewed)abstract
- We present a new measurement of the WZ -> lvll (l = e, mu) cross section and limits on anomalous triple gauge couplings. Using 4.1 fb(-1) of integrated luminosity of p (p) over bar collisions at root s = 1.96 TeV, we observe 34 WZ candidate events with an estimated background of 6.0 +/- 0.4 events. We measure the WZ production cross section to be 3.89(-0.90)(+1.07) pb, in good agreement with the standard model prediction. We find no evidence for anomalous WWZ couplings and set 95% C.L. limits on the coupling parameters, -0.077 < lambda(z) < 0.093 and -0.029 < Delta kappa(z) < 0.080 in the HISZ parameterization for a Lambda = 2 TeV form factor scale. These are the best limits to date obtained from the direct measurement of the WWZ vertex.
|
|
| 27. |
- Abazov, V. M., et al.
(author)
-
Search for a heavy neutral gauge boson in the dielectron channel with 5.4 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. ; 695:1-4, s. 88-94
-
Journal article (peer-reviewed)abstract
- We report the results of a search for a heavy neutral gauge boson Z' decaying into the dielectron final state using data corresponding to an integrated luminosity of 5.4 fb(-1) collected by the D0 experiment at the Fermilab Tevatron Collider. No significant excess above the standard model prediction is observed in the dielectron invariant-mass spectrum. We set 95 sigma(p (p) over bar -> Z') x BR(Z' -> ee) depending on the dielectron invariant mass. These cross section limits are used to determine lower mass limits for bosons in a variety of models. For the sequential standard model boson a lower mass limit of 1023 GeV is obtained.
|
|
| 28. |
- Abazov, V. M., et al.
(author)
-
Search for a Resonance Decaying into WZ Boson Pairs in p(p)over-bar Collisions
- 2010
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061801-
-
Journal article (peer-reviewed)abstract
- We present the first search for an electrically charged resonance W' decaying to a WZ boson pair using 4.1 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron p (p) over bar collider. The WZ pairs are reconstructed through their decays into three charged leptons (l = e, mu). A total of 9 data events is observed in good agreement with the background prediction. We set 95% C.L. limits on the W'WZ coupling and on the W' production cross section multiplied by the branching fractions. We also exclude W' masses between 188 and 520 GeV within a simple extension of the standard model and set the most restrictive limits to date on low-scale technicolor models.
|
|
| 29. |
- 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.
|
|
| 30. |
- Abazov, V. M., et al.
(author)
-
Search for scalar bottom quarks and third-generation leptoquarks in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:2, s. 95-101
-
Journal article (peer-reviewed)abstract
- We report the results of a search for pair production of scalar bottom quarks ((b) over bar (1)) and scalar third-generation leptoquarks (LQ(3)) in 5.2 fb(-1) of p (p) over bar collisions at the D0 experiment of the Fermilab Tevatron Collider. Scalar bottom quarks are assumed to decay to a neutralino ((chi) over bar (1)(0)) and a b quark, and we set 95% C.L. lower limits on their production in the (m((b) over bar1), m((chi) over bar 10)) mass plane such as m((b) over bar1) > 247 GeV for m(<(chi)over) (bar>10) = 0 and m((chi) over bar 10) > 110 GeV for 160 m(<(b) over bar1) < 200 GeV. The leptoquarks are assumed to decay to a tau neutrino and a b quark, and we set a 95% C.L. lower limit of 247 GeV on the mass of a charge-1/3 third-generation scalar leptoquark.
|
|
| 31. |
- Abazov, V. M., et al.
(author)
-
Search for single top quarks in the tau plus jets channel using 4.8 fb(-1) of p(p)over-bar collision data
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 690:1, s. 5-14
-
Journal article (peer-reviewed)abstract
- We present the first direct search for single top quark production using reconstructed tau leptons in the final state. The search is based on 4.8 fb(-1) of integrated luminosity collected in p (p) over bar collisions at root s= 1.96 TeV with the D0 detector at the Fermilab Tevatron Collider. We select events with a final state including an isolated tau lepton. missing transverse energy, two or three jets, one or two of them being identified as b quark jet. We use a multivariate technique to discriminate signal from background. The number of events observed in data in this final state is consistent with the signal plus background expectation. We set in the tau + jets channel an upper limit on the single top quark cross section of 7.3 pb at the 95% C.L. This measurement allows a gain of 4% in expected sensitivity for the observation of single top production when combining it with electron + jets and muon + jets channels already published by the DO Collaboration with 2.3 fb(-1) of data. We measure a combined cross section of 3.84(-0.83)(+0.89) pb, which is the most precise measurement to date.
|
|
| 32. |
- Abazov, V. M., et al.
(author)
-
Search for the Associated Production of a b Quark and a Neutral Supersymmetric Higgs Boson that Decays into τ Pairs
- 2010
-
In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 104:15
-
Journal article (peer-reviewed)abstract
- We report results from a search for production of a neutral Higgs boson in association with a b quark. We search for Higgs decays to tau pairs with one tau subsequently decaying to a muon and the other to hadrons. The data correspond to 2: 7 fb(-1) of p (p) over bar collisions recorded by the D0 detector at.. root s = 1.96 TeV. The data are found to be consistent with background predictions. The result allows us to exclude a significant region of parameter space of the minimal supersymmetric model.
|
|
| 33. |
- Abazov, V. M., et al.
(author)
-
Search for the rare decay B-s(0) -> mu(+)mu(-)
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:5, s. 539-544
-
Journal article (peer-reviewed)abstract
- We present the results of a search for the flavor changing neutral current decay B-s(0) -> mu(+)mu(-) using 6.1 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B-s(0) candidates is consistent with background expectations. The resulting upper limit on the branching fraction is B(B-s(0) -> mu(+)mu(-)) < 5.1 x 10(-8) at the 95% C.L. This limit is a factor of 2.4 better than that of the previous DO analysis and the best limit to date. Published by Elsevier B.V.
|
|
| 34. |
- Abazov, V. M., et al.
(author)
-
Measurement of the t-channel single top quark production cross section
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 682:4-5, s. 363-369
-
Journal article (peer-reviewed)abstract
- The DO Collaboration reports direct evidence for electroweak production of single top quarks through the t-channel exchange of a virtual W boson. This is the first analysis to isolate an individual single top quark production channel. We select events containing an isolated electron or muon, missing transverse energy, and two, three or four jets from 2.3 fb(-1) of p (p) over bar collisions at the Fermilab Tevatron Collider. One or two of the jets are identified as containing a b hadron. We combine three multivariate techniques optimized for the t-channel process to measure the t- and s-channel cross sections simultaneously. We measure cross sections of 3.14(-0.80)(+0.94) pb for the t-channel and 1.05 +/- 0.81 pb for the s-channel. The measured t-channel result is found to have a significance of 4.8 standard deviations and is consistent with the standard model prediction.
|
|
| 35. |
- Abazov, V. M., et al.
(author)
-
Measurement of Z/gamma* plus jet plus X angular distributions in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 682:4-5, s. 370-380
-
Journal article (peer-reviewed)abstract
- We present the first measurements at a hadron collider of differential cross sections for Z/gamma* + jet + X production in Delta phi(Z. jet), vertical bar Delta y(Z, jet)vertical bar and vertical bar y(boost)(Z + jet)vertical bar. Vector boson production in association with jets is an excellent probe of QCD and constitutes the main background to many small cross section processes, such as associated Higgs production. These measurements are crucial tests of the predictions of perturbative QCD and current event generators, which have varied success in describing the data. Using these measurements as inputs in tuning event generators will increase the experimental sensitivity to rare signals.
|
|
| 36. |
- Abazov, V. M., et al.
(author)
-
Search for charged Higgs bosons in top quark decays
- 2009
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 682:3, s. 278-286
-
Journal article (peer-reviewed)abstract
- We present a search for charged Higgs bosons in top quark decays. We analyze the e + jets, mu + jets, ee, e mu, mu mu, tau e and tau mu final states from top quark pair production events, using data from about 1 fb (1) of integrated luminosity recorded by the DO experiment at the Fermilab Tevatron Collider. We consider different scenarios of possible charged Higgs boson decays, one where the charged Higgs boson decays purely hadronically into a charm and a strange quark, another where it decays into a tau lepton and a tau neutrino and a third one where both decays appear. We extract limits on the branching ratio B(t -> H(+)b) for all these models. We use two methods, one where the t (t) over bar production cross section is fixed, and one where the cross section is fitted simultaneously with B(t -> H(+)b). Based on the extracted limits, we exclude regions in the charged Higgs boson mass and tan beta parameter space for different scenarios of the minimal supersymmetric standard model.
|
|
| 37. |
- Abazov, V. M., et al.
(author)
-
Search for flavor changing neutral currents via quark-gluon couplings in single top quark production using 2.3 fb(-1) of p(p)over-bar collisions
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:2, s. 81-87
-
Journal article (peer-reviewed)abstract
- We present a search for flavor changing neutral currents via quark-gluon couplings in a sample of single top quark final states corresponding to 2.3 fb(-1) of integrated luminosity collected with the DO detector at the Fermilab Tevatron Collider. We select events containing a single top quark candidates with an additional jet, and obtain separation between signal and background using Bayesian neural networks. We find consistency between background expectation and observed data, and set limits on flavor changing neutral current gluon couplings of the top quark to up quarks (tgu) and charm quarks (tgc). The cross section limits at the 95% C.L. are sigma(tgu) < 0.20 pb and sigma(tgc) < 0.27 pb. These correspond to limits on the top quark decay branching fractions of B(t -> gu) < 2.0 x 10(-4) and B(t -> gc) < 3.9 x 10(-3).
|
|
| 38. |
- Abazov, V. M., et al.
(author)
-
Measurement of the normalized Z/gamma* -> mu(+)mu(-) transverse momentum distribution in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:5, s. 522-530
-
Journal article (peer-reviewed)abstract
- We present a new measurement of the Z/gamma* transverse momentum distribution in the range 0-330 GeV, in proton-antiproton collisions at root s = 1.96 TeV. The measurement uses 0.97 fb(-1) of integrated luminosity recorded by the D0 experiment and is the first using the Z/gamma* -> mu(+)mu(-) + X channel at this center-of-mass energy. This is also the first measurement of the Z/gamma* transverse momentum distribution that presents the result at the level of particles entering the detector, minimizing dependence on theoretical models. As any momentum of the Z/gamma* in the plane transverse to the incoming beams must be balanced by some recoiling system, primarily the result of QCD radiation in the initial state, this variable is an excellent probe of the underlying process. Tests of the predictions of QCD calculations and current event generators show they have varied success in describing the data. Using this measurement as an input to theoretical predictions will allow for a better description of hadron collider data and hence it will increase experimental sensitivity to rare signals. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 39. |
- Abazov, V. M., et al.
(author)
-
Search for the Standard Model Higgs Boson in the ZH -> v(v)over-barb(b)over-bar Channel in 5.2 fb(-1) of p(p)over-bar Collisions at root s=1.96 TeV
- 2010
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:7, s. 071801-
-
Journal article (peer-reviewed)abstract
- A search is performed for the standard model Higgs boson in 5.2 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron Collider. The final state considered is a pair of b jets and large missing transverse energy, as expected from p (p) over bar -> ZH -> v (v) over barb (b) over bar production. The search is also sensitive to the WH -> lvb (b) over bar channel when the charged lepton is not identified. For a Higgs boson mass of 115 GeV, a limit is set at the 95% C.L. on the cross section multiplied by branching fraction for [p (p) over bar -> (Z/W)H](H -> b (b) over bar) that is a factor of 3.7 larger than the standard model value, consistent with the factor of 4.6 expected.
|
|
| 40. |
- Abazov, M, et al.
(author)
-
Measurement of differential Z/gamma* plus jet plus X cross sections in p(p)over-bar collisions at root S=1.96 TeV
- 2008
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 669:5, s. 278-286
-
Journal article (peer-reviewed)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.
|
|
| 41. |
- Abazov, M, et al.
(author)
-
Search for squark production in events with jets, hadronically decaying tau leptons and missing transverse energy at root s=1.96 TeV
- 2009
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 680:1, s. 24-33
-
Journal article (peer-reviewed)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.
|
|
| 42. |
- Abazov, V. M., et al.
(author)
-
Double parton interactions in gamma+3 jet events in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
In: Physical Review D. - 1550-7998 .- 1550-2368. ; 81:5, s. 052012-
-
Journal article (peer-reviewed)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.
|
|
| 43. |
- Abazov, V. M., et al.
(author)
-
Evidence for an anomalous like-sign dimuon charge asymmetry
- 2010
-
In: Physical Review D. - 1550-7998. ; 82:13, s. 032001-
-
Journal article (peer-reviewed)abstract
- We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb(-1) of p (p) over bar collisions recorded with the D0 detector at a center-of-mass energy root s = 1.96 TeV at the Fermilab Tevatron collider. From A, we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.00957 +/- 0.00251 (stat) +/- 0.00146 (syst). This result differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(0.6)(+0.5)) x 10(-4) and provides first evidence of anomalous CP violation in the mixing of neutral B mesons.
|
|
| 44. |
- Abazov, V. M., et al.
(author)
-
Evidence for an Anomalous Like-Sign Dimuon Charge Asymmetry
- 2010
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 105:8, s. 081801-
-
Journal article (peer-reviewed)abstract
- We measure the charge asymmetry A =(N++ -N--)/(N++ + N--) of like-sign dimuon events in 6.1 fb(-1) of p (p) over bar collisions recorded with the D0 detector at a center-of-mass energy root s = 1: 96 TeV at the Fermilab Tevatron collider. From A we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.009 57 +/- 0.00251(stat) +/- 0.001 46(sys). It differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(-0.6)(+0.5)) x 10(-4), and provides first evidence of anomalous CP violation in the mixing of neutral B mesons.
|
|
| 45. |
- Abazov, V. M., et al.
(author)
-
Search for Higgs Boson Production in Dilepton and Missing Energy Final States with 5.4 fb(-1) of p(p)over-bar Collisions at root s=1.96 TeV
- 2010
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061804-
-
Journal article (peer-reviewed)abstract
- A search for the standard model Higgs boson is presented using events with two charged leptons and large missing transverse energy selected from 5.4 fb(-1) of integrated luminosity in p ($) over bar collisions at root s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron collider. No significant excess of events above background predictions is found, and observed (expected) upper limits at 95% confidence level on the rate of Higgs boson production are derived that are a factor of 1.55 (1.36) above the predicted standard model cross section at m(H) = 165 GeV.
|
|
| 46. |
|
|
| 47. |
- Abazov, M, et al.
(author)
-
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
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 679:3, s. 177-185
-
Journal article (peer-reviewed)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.
|
|
| 48. |
- 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.
|
|
| 49. |
- Abazov, V. M., et al.
(author)
-
Measurement of direct photon pair production cross sections in p(p)over-bar collisions at root s=1.96 TeV
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 690:2, s. 108-117
-
Journal article (peer-reviewed)abstract
- We present a measurement of direct photon pair production cross sections using 4.2 fb(-1) of data collected with the DO detector at the Fermilab Tevatron p (p) over bar Collider. We measure single differential cross sections as a function of the diphoton mass, the transverse momentum of the diphoton system, the azimuthal angle between the photons, and the polar scattering angle of the photons. In addition, we measure double differential cross sections considering the last three kinematic variables in three diphoton mass bins. The results are compared with different perturbative QCD predictions and event generators. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 50. |
- Abazov, M, et al.
(author)
-
Evidence of WW and WZ Production with lepton plus jets Final States in pp Collisions at root s=1.96 TeV
- 2009
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:16, s. 161801-
-
Journal article (peer-reviewed)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.
|
|
