| 281. |
- Abazov, V. M., et al.
(författare)
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Measurement of the differential gamma+2b-jet cross section and the ration sigma(gamma+2b-jets)/sigma(gamma plus b-jet) in p(p)over-bar collisions at root s=1.96 TeV
- 2014
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 737, s. 357-365
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Tidskriftsartikel (refereegranskat)abstract
- We present the first measurements of the differential cross section d sigma/dp(T)(gamma) for the production of an isolated photon in association with at least two b-quark jets. The measurements consider photons with rapidities vertical bar y(gamma)vertical bar < 1.0 and transverse momenta 30 < p(T)(gamma) < 200 GeV. The b-quark jets are required to have p(T)(jet) > 15 GeVand vertical bar y(jet)vertical bar < 1.5. The ratio of differential production cross sections for gamma + 2 b-jets to gamma + b-jet as a function of p(T)(gamma) is also presented. The results are based on the proton-antiproton collision data at root s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. The measured cross sections and their ratios are compared to the next- to- leading order perturbative QCD calculations as well as predictions based on the k(T)- factorization approach and those from the sherpa and pythia Monte Carlo event generators.
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| 282. |
- Abazov, V. M., et al.
(författare)
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Measurement of the direct CP violating charge asymmetry in B-+/- -> mu(+/-)nu D-mu(0) decays
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:3
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Tidskriftsartikel (refereegranskat)abstract
- We present the first measurement of the CP violating charge asymmetry in B-+/- -> mu(+/-)nu D-mu(0) decays using the full Run II integrated luminosity of 10.4 fb(-1) in proton-antiproton collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure a difference in the yield of B- and B+ mesons in these decays by fitting the reconstructed invariant mass distributions. This results in an asymmetry of A(mu D0) = [-0.14 +/- 0.20] %, which is consistent with standard model predictions.
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| 283. |
- Abazov, V. M., et al.
(författare)
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Measurement of the Direct CP-violating Charge Asymmetry in D-s(+/-) -> Phi pi(+/-) Decays
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:11, s. 111804-
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the direct CP-violating charge asymmetry in D-s(+) -> phi pi(+/-) decays where the phi meson decays to K+ K-, using the full Run II data set with an integrated luminosity of 10.4 fb(-1) of proton- antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. The normalized difference A(CP) in the yield of D-s(+) and D-s(-) mesons in these decays is measured by fitting the difference between their reconstructed invariant mass distributions. This results in an asymmetry of A(CP) = [-0.38 +/- 0.27]%, which is the most precise measurement of this quantity to date. The result is consistent with the standard model prediction of zero CP asymmetry in this decay.
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| 284. |
- Abazov, V. M., et al.
(författare)
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Measurement of the direct CP-violating parameter A(CP) in the decay D+ -> K-pi(+)pi(+)
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:11, s. 111102-
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Tidskriftsartikel (refereegranskat)abstract
- We measure the direct CP-violating parameter A(CP) for the decay of the charged charm meson, D+ -> K-pi(+)pi(+)(and charge conjugate), using the full 10.4 fb(-1) sample of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 detector at the Fermilab Tevatron collider. We extract the raw reconstructed charge asymmetry by fitting the invariant mass distributions for the sum and difference of charge-specific samples. This quantity is then corrected for detector-related asymmetries using data-driven methods and for possible physics asymmetries (from B. D processes) using input from Monte Carlo simulation. We measure A(CP) =[-0.16 +/- 0.15(stat) +/- 0.09(syst)] %, which is consistent with zero, as expected from the standard model prediction of CP conservation, and is the most precise measurement of this quantity to date.
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| 285. |
- Abazov, V. M., et al.
(författare)
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Measurement of the Effective Weak Mixing Angle in p(p)over-bar -> Z/gamma* -> e(+)e(-) Events
- 2015
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:4
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin(2)theta(l)(eff) which determines the relative strength of weak and electromagnetic interactions, in p (p) over bar -> Z/gamma* -> e(+)e(-) events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb(-1) of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin(2)theta(l)(eff) = 0.23147 +/- 0.00047 is the most precise measurement from light quark interactions to date, with a precision close to the best LEP and SLD results.
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| 286. |
- Abazov, V. M., et al.
(författare)
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Measurement of the electric charge of the top quark in t(t)over-bar events
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:5, s. 051101-
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the electric charge of top quarks using t (t) over bar events produced in p (p) over bar collisions at the Tevatron. The analysis is based on fully reconstructed t (t) over bar pairs in lepton + jets final states. Using data corresponding to 5.3 fb(-1) of integrated luminosity, we exclude the hypothesis that the top quark has a charge of Q = -4/3e at a significance greater than 5 standard deviations. We also place an upper limit of 0.46 on the fraction of such quarks that can be present in an admixture with the standard model top quarks (Q = +2/3e) at a 95% confidence level.
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| 287. |
- Abazov, V. M., et al.
(författare)
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Measurement of the electron charge asymmetry in p(p)over-bar -> W + X -> ev plus X decays in p(p)over-bar collisions at root S=1.96 TeV
- 2015
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:3
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the electron charge asymmetry in p (p) over bar -> W + X -> ev + X events at a center-of-mass energy of 1.96 TeV, using data corresponding to 9.7 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron pseudorapidity and is presented in five kinematic bins based on the electron transverse energy and the missing transverse energy in the event. The measured asymmetry is compared with next-to-leading-order predictions in perturbative quantum chromodynamics and provides accurate information for the determination of parton distribution functions of the proton. This is the most precise lepton charge asymmetry measurement to date.
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| 288. |
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| 289. |
- Abazov, V. M., et al.
(författare)
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Measurement of the forward-backward asymmetry in Lambda(0)(b) and (Lambda)over-bar(b)(0) baryon production in p(p)over-bar collisions at root s=1.96 TeV
- 2015
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:7
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Tidskriftsartikel (refereegranskat)abstract
- We measure the forward-backward asymmetry in the production of Lambda(0)(b) and (Lambda) over bar (0)(b) baryons as a function of rapidity in p (p) over bar collisions at root s = 1.96 TeV using 10.4 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron collider. The asymmetry is determined by the preference of Lambda(0)(b) or (Lambda) over bar (0)(b) particles to be produced in the direction of the beam protons or antiprotons, respectively. The measured asymmetry integrated over rapidity y in the range 0.1 < vertical bar y vertical bar < 2.0 is A = 0.04 +/- 0.07(stat) +/- 0.02(syst).
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| 290. |
- Abazov, V. M., et al.
(författare)
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Measurement of the forward-backward asymmetry in the distribution of leptons in t(t)over-bar events in the lepton plus jets channel
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:7, s. 072001-
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the forward-backward asymmetry in the angular distribution of leptons from decays of top quarks and antiquarks produced in proton-antiproton collisions. We consider the final state containing a lepton and at least three jets. The entire sample of data collected by the D0 experiment during Run II of the Fermilab Tevatron Collider, corresponding to 9.7 fb(-1) of integrated luminosity, is used. The asymmetry measured for reconstructed leptons is A(FB)(l) = (2.9 +/- 2.1(stat.)(-1.7)(+1.5) (syst.))%. When corrected for efficiency and resolution effects within the lepton rapidity coverage of vertical bar y(l)vertical bar < 1.5, the asymmetry is found to be A(FB)(l) = (4.2 +/- 2.3(stat.)(-2.0)(+1.7) (syst.))%. We examine the dependence of A(FB)(l) on the transverse momentum and rapidity of the lepton. Combination with the asymmetry measured in the final states containing two leptons yields A(FB)(l) = (4.2 +/- 2.0(stat.) +/- 1.4(syst.))%. The results are in agreement with predictions from the next-to-leading-order QCD generator MC@NLO, which predicts an asymmetry of A(FB)(l) = 2.0% for vertical bar y(l)vertical bar < 1.5.
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