| 11. |
- Abazov, V. M., et al.
(author)
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Evidence for Simultaneous Production of J/psi and Upsilon Mesons
- 2016
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 116:8
-
Journal article (peer-reviewed)abstract
- We report evidence for the simultaneous production of J/psi and Upsilon mesons in 8.1 fb(-1) of data collected at root s = 1.96 TeV by the D0 experiment at the Fermilab p (p) over bar Tevatron Collider. Events with these characteristics are expected to be produced predominantly by gluon-gluon interactions. In this analysis, we extract the effective cross section characterizing the initial parton spatial distribution, sigma(eff) = 2.2 +/- 0.7(stat) +/- 0.9(syst) mb.
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| 12. |
- Abazov, V. M., et al.
(author)
-
Inclusive Production of the X(4140) State in p(p)over-bar Collisions at D0
- 2015
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:23
-
Journal article (peer-reviewed)abstract
- We present a study of the inclusive production of the X(4140) state with the decay to the J/psi phi final state in hadronic collisions. Based on 10.4 fb(-1) of p (p) over bar collision data collected by the D0 experiment at the Fermilab Tevatron collider, we report the first evidence for the prompt production of an X(4140) state and find the fraction of X(4140) events originating from b hadrons to be f(b) = 0.39 +/- 0.07 (stat) +/- 0.10 (syst). The ratio of the nonprompt X(4140) production rate to the B-s(0) yield in the same channel is R = 0.19 +/- 0.05 (stat) +/- 0.07 (syst). The values of the mass M = 4152.5 +/- 1.7 (stat)(-5.4)(+/- 6.2)(syst) MeV and width Gamma = 16.3 +/- 5.6 (stat) +/- 11.4 (syst) MeV are consistent with previous measurements.
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| 13. |
- Abazov, V. M., et al.
(author)
-
Measurement of spin correlation between top and antitop quarks produced in p(p)over-bar collisions at root s=1.96 TeV
- 2016
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 757, s. 199-206
-
Journal article (peer-reviewed)abstract
- We present a measurement of the correlation between the spins of t and (t) over bar quarks produced in proton-antiproton collisions at the Tevatron Collider at a center-of-mass energy of 1.96 TeV. We apply a matrix element technique to dilepton and single-lepton+jets final states in data accumulated with the DO detector that correspond to an integrated luminosity of 9.7 fb(-1). The measured value of the correlation coefficient in the off-diagonal basis, O-off = 0.89 +/- 0.22 (stat + syst), is in agreement with the standard model prediction, and represents evidence for a top-antitop quark spin correlation difference from zero at a level of 4.2 standard deviations.
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| 14. |
- Abazov, V. M., et al.
(author)
-
Measurement of the direct CP violating charge asymmetry in B-+/- -> mu(+/-)nu D-mu(0) decays
- 2017
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:3
-
Journal article (peer-reviewed)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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| 15. |
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| 16. |
- Abazov, V. M., et al.
(author)
-
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
-
In: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:7
-
Journal article (peer-reviewed)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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| 17. |
- Abazov, V. M., et al.
(author)
-
Measurement of the forward-backward asymmetry of Lambda and (Lambda)over-bar production in p(p)over-bar collisions
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 93:3
-
Journal article (peer-reviewed)abstract
- We study Lambda and (Lambda) over bar production asymmetries in p (p) over bar -> Lambda((Lambda) over bar )X, p (p) over bar -> J/psi Lambda((Lambda) over bar )X, and p (p) over bar -> mu(+/-)Lambda((Lambda) over bar )X events recorded by the D0 detector at the Fermilab Tevatron collider at root s = 1.96 TeV. We find an excess of Lambda's ((Lambda) over bar 's) produced in the proton (antiproton) direction. This forward-backward asymmetry is measured as a function of rapidity. We confirm that the (Lambda) over bar/Lambda production ratio, measured by several experiments with various targets and a wide range of energies, is a universal function of "rapidity loss," i.e., the rapidity difference of the beam proton and the lambda.
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| 18. |
- Abazov, V. M., et al.
(author)
-
Measurement of the inclusive t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV and determination of the top quark pole mass
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 94:9
-
Journal article (peer-reviewed)abstract
- The inclusive cross section of top quark-antiquark pairs produced in p (p) over bar collisions at root s = 1.96 TeV is measured in the lepton + jets and dilepton decay channels. The data sample corresponds to 9.7 fb(-1) of integrated luminosity recorded with the D0 detector during Run II of the Fermilab Tevatron Collider. Employing multivariate analysis techniques we measure the cross section in the two decay channels and we perform a combined cross section measurement. For a top quark mass of 172.5 GeV, we measure a combined inclusive top quark-antiquark pair production cross section of sigma(t<(t)over bar) = 7.26 +/- 0.13(stat)(-0.50)(+0.57) (syst) pb which is consistent with standard model predictions. We also perform a likelihood fit to the measured and predicted top quark mass dependence of the inclusive cross section, which yields a measurement of the pole mass of the top quark. The extracted value is m(t) = 172.8 +/- 1.1(theo)(-3.1)(+3.3) (exp) GeV.
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| 19. |
- Abazov, V. M., et al.
(author)
-
Measurement of the top quark mass using the matrix element technique in dilepton final states
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 94:3
-
Journal article (peer-reviewed)abstract
- We present a measurement of the top quark mass in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb(-1). The matrix element technique is applied to t (t) over bar events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton + jets final state of t (t) over bar decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of m(t) = 173.93 +/- 1.84 GeV.
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| 20. |
- Abazov, V. M., et al.
(author)
-
Measurement of top quark polarization in t(t)over-bar lepton+jets final states
- 2017
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 95:1
-
Journal article (peer-reviewed)abstract
- We present a measurement of top quark polarization in t (t) over bar pair production in p (p) over bar collisions at root s = 1.96 TeV using data corresponding to 9.7 fb(-1) of integrated luminosity recorded with the D0 detector at the Fermilab Tevatron Collider. We consider final states containing a lepton and at least three jets. The polarization is measured through the distribution of lepton angles along three axes: the beam axis, the helicity axis, and the transverse axis normal to the t (t) over bar production plane. This is the first measurement of top quark polarization at the Tevatron using lepton + jet final states and the first measurement of the transverse polarization in t (t) over bar production. The observed distributions are consistent with standard model predictions of nearly no polarization.
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