| 241. |
- Abazov, V. M., et al.
(författare)
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Measurement of the semileptonic charge asymmetry in B-0 meson mixing with the D0 detector
- 2012
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 86:7, s. 072009-
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the semileptonic mixing asymmetry for B-0 mesons, a(sl)(d), using two independent decay channels: B-0 -> mu+D-X, with D- ->! K+ pi(-) pi(-); and B-0 -> mu+D*X-, with D*(-) -> (D) over bar (0) pi(-), (D) over bar (-)(0) K+ pi(-) (and charge conjugate processes). We use a data sample corresponding to 10.4 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV, collected with the D0 experiment at the Fermilab Tevatron collider. We extract the charge asymmetries in these two channels as a function of the visible proper decay length of the B-0 meson, correct for detector-related asymmetries using data-driven methods, and account for dilution from charge-symmetric processes using Monte Carlo simulation. The final measurement combines four signal visible proper decay length regions for each channel, yielding a(sl)(d) = [0.68 +/- 0: 45(stat) +/- 0.14(syst)]%. This is the single most precise measurement of this parameter, with uncertainties smaller than the current world average of B factory measurements.
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| 242. |
- Abazov, V. M., et al.
(författare)
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Measurement of the W boson mass with the D0 detector
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:1, s. 012005-
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Tidskriftsartikel (refereegranskat)abstract
- We give a detailed description of the measurement of the W boson mass, M-W, performed on an integrated luminosity of 4.3 fb(-1), which is based on similar techniques as used for our previous measurement done on an independent data set of 1 fb(-1) of data. The data were collected using the D0 detector at the Fermilab Tevatron Collider. This data set yields 1.68 x 10(6) W -> ev candidate events. We measure the mass using the transverse mass, electron transverse momentum, and missing transverse energy distributions. The M-W measurements using the transverse mass and the electron transverse momentum distributions are the most precise of these three and are combined to give M-W 80.367 +/- 0.013 (stat) +/- 0.022(syst) GeV = 80: 367 +/- 0.026 GeV. When combined with our earlier measurement on 1 fb(-1) of data, we obtain M-W = 80.375 +/- 0.023 GeV.
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| 243. |
- Abazov, V. M., et al.
(författare)
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Muon reconstruction and identification with the Run II D0 detector
- 2014
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 737, s. 281-294
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Tidskriftsartikel (refereegranskat)abstract
- We present an overview of the muon reconstruction and identification methods employed by the DO collaboration to analyze the Run II (2001-2011) p (p) over bar data of the Fermilab Tevatron collider at root s = 1.96 TeV. We discuss the performance of these methods, how it is measured using DO data, and how it is properly modeled by the DO simulation program. In its pseudorapidity acceptance, vertical bar eta vertical bar < 2, the muon system identifies high-p(T) muons (p(T) greater than or similar to 10 GeV) with efficiencies ranging from 72% to 89%. Muons tracks are reconstructed in the DO central tracking system with efficiencies ranging from 85% to 92% and with a typical relative momentum resolution of 10% for p(T) = 40 GeV. Isolation criteria reject multijet background with efficiencies of 87-99%.
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| 244. |
- Abazov, V. M., et al.
(författare)
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Combination of D0 measurements of the top quark mass
- 2017
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:11
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Tidskriftsartikel (refereegranskat)abstract
- We present a combination of measurements of the top quark mass by the D0 experiment in the lepton + jets and dilepton channels. We use all the data collected in Run I (1992-1996) at root s = 1.8 TeV and Run II (2001-2011) at root s = 1.96 TeV of the Tevatron p (p) over bar collider, corresponding to integrated luminosities of 0.1 fb(-1) and 9.7 fb(-1), respectively. The combined result is: m(t) = 174.95 +/- 0.40(stat)+/- 0.64(syst) GeV = 174.95 +/- 0.75 GeV.
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| 245. |
- Abazov, V. M., et al.
(författare)
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Combined search for the Higgs boson with the D0 experiment
- 2013
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:5, s. 052011-
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Tidskriftsartikel (refereegranskat)abstract
- We perform a combination of searches for standard model Higgs boson production in p (p) over bar collisions recorded by the D0 detector at the Fermilab Tevatron Collider at a center of mass energy of root s = 1.96 TeV. The different production and decay channels have been analyzed separately, with integrated luminosities of up to 9.7 fb(-1) and for Higgs boson masses 90 <= M-H <= 200 GeV. We combine these final states to achieve optimal sensitivity to the production of the Higgs boson. We also interpret the combination in terms of models with a fourth generation of fermions, and models with suppressed Higgs boson couplings to fermions. The result excludes a standard model Higgs boson at 95% C.L. in the ranges 90 < M-H < 101 GeV and 157 < M-H < 178 GeV, with an expected exclusion of 155 < M-H < 175 GeV. In the range 120 < M-H < 145 GeV, the data exhibit an excess over the expected background of up to 2 standard deviations, consistent with the presence of a standard model Higgs boson of mass 125 GeV.
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| 246. |
- Abazov, V. M., et al.
(författare)
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Measurement of the combined rapidity and p(T) dependence of dijet azimuthal decorrelations in p(p)over-bar collisions at root s=1.96 TeV
- 2013
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 721:4-5, s. 212-219
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Tidskriftsartikel (refereegranskat)abstract
- We present the first combined measurement of the rapidity and transverse momentum dependence of dijet azimuthal decorrelations, using the recently proposed quantity R-Delta phi. The variable R-Delta phi measures the fraction of the inclusive dijet events in which the azimuthal separation of the two jets with the highest transverse momenta is less than a specified value of the parameter Delta phi(max). The quantity R-Delta phi is measured in p (p) over bar collisions at root s = 1.96 TeV, as a function of the dijet rapidity interval, the total scalar transverse momentum, and Delta phi(max). The measurement uses an event sample corresponding to an integrated luminosity of 0.7 fb(-1) collected with the DO detector at the Fermilab Tevatron Collider. The results are compared to predictions of a perturbative QCD calculation at next-to-leading order in the strong coupling with corrections for non-perturbative effects. The theory predictions describe the data well, except in the kinematic region of large dijet rapidity intervals and small Delta phi(max).
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| 247. |
- Abazov, V. M., et al.
(författare)
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Measurement of the differential cross sections for isolated direct photon pair production in p(p)over-bar collisions at root s=1.96 TeV
- 2013
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 725:1-3, s. 6-14
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of direct photon pair production cross sections using 8.5 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron p (p) over bar collider. The results are presented as differential distributions of the photon pair invariant mass d sigma/dM(gamma gamma), pair transverse momentum d sigma/dp(T)(gamma gamma) azimuthal angle between the photons d sigma/d Delta(phi)(gamma gamma), and polar scattering angle in the Collins-Soper frame d sigma/d vertical bar cos theta*vertical bar. Measurements are performed for isolated photons with transverse momenta p(T)(gamma) > 18 (17) GeV for the leading (next-to-leading) photon in P-T, pseudorapidities vertical bar eta(gamma)vertical bar < 0.9, and a separation in eta-phi space Delta R-gamma gamma > 0.4. We present comparisons with the predictions from Monte Carlo event generators DIPHOX and RESBOS implementing QCD calculations at next-to-leading order, 2 gamma NNLO at next-to-next-to-leading order, and SHERPA using matrix elements with higher-order real emissions matched to parton shower.
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| 248. |
- Abazov, V. M., et al.
(författare)
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Measurement of the Effective Weak Mixing Angle in p¯p→Z/γ∗→ℓ+ℓ− Events
- 2018
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 120:24
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the effective weak mixing angle parameter sin(2)theta(l)(eff) in p (p) over bar -> Z/gamma* -> mu(+)mu(-) events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron Collider and corresponding to 8.6 fb(-1) of integrated luminosity. The measured value of sin(2)theta(l)(eff)[mu mu] = 0.23016 +/- 0.00064 is further combined with the result from the D0 measurement in p (p) over bar -> Z/gamma* -> e(+)e(-) events, resulting in sin(2)theta(l)(eff)[comb] = 0.23095 +/- 0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/gamma* to light quarks.
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| 249. |
- Abazov, V. M., et al.
(författare)
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Measurement of the ratio of differential cross sections sigma(p(p)over-bar -> Z + b jet)/sigma(p(p)over-bar -> Z + jet) in p(p)over-bar collisions at root s = 1.96 TeV
- 2013
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 87:9, s. 092010-
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Tidskriftsartikel (refereegranskat)abstract
- We measure the ratio of cross sections, sigma(p (p) over bar -> Z + b jet)/sigma(p (p) over bar -> Z + jet), for associated production of a Z boson with at least one jet. The ratio is also measured as a function of the Z boson transverse momentum, jet transverse momentum, jet pseudorapidity, and the azimuthal angle between the Z boson with respect to the highest p(T) b tagged jet. These measurements use data collected by the D0 experiment in Run II of Fermilab's Tevatron p (p) over bar Collider at a center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity of 9.7 fb(-1). The results are compared to predictions from next-to-leading order calculations and various Monte Carlo event generators.
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| 250. |
- Abazov, V. M., et al.
(författare)
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Precision Measurement of the Top Quark Mass in Lepton plus Jets Final States
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 113:3, s. 032002-
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Tidskriftsartikel (refereegranskat)abstract
- We measure the mass of the top quark in lepton + jets final states using the full sample of p (p) over bar collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at root s = 1.96 TeV, corresponding to 9.7 fb(-1) of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from t (t) over bar production or background. The overall jet energy scale is constrained in situ by the mass of theW boson. We measure m(t) = 174.98 +/- 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass.
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