1. |
- Aaltonen, T., et al.
(författare)
-
Tevatron Run II combination of the effective leptonic electroweak mixing angle
- 2018
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:11
-
Tidskriftsartikel (refereegranskat)abstract
- Drell-Yan lepton pairs produced in the process p (p) over bar -> l(+)l(-) + X through an intermediate gamma*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin(2) theta(lept)(eff) using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9-10 fb(-1) of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin(2)theta(lept)(eff) = 0.23148 +/- 0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin(2) theta(W), or equivalently the W-boson mass M-W, using the ZFITTER software package yields sin(2) theta(W) = 0.22324 +/- 0.00033 or equivalently, M-W = 80.367 +/- 0.017 GeV/c(2).
|
|
2. |
- Aaltonen, T., et al.
(författare)
-
Combination of measurements of the top-quark pair production cross section from the Tevatron Collider
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7
-
Tidskriftsartikel (refereegranskat)abstract
- We combine six measurements of the inclusive top-quark pair (t(sic)) production cross section (sigma(t)(sic)) from data collected with the CDF and D0 detectors at the Fermilab Tevatron with proton-antiproton collisions at root s = 1.96 TeV. The data correspond to integrated luminosities of up to 8.8 fb(-1). We obtain a value of sigma tt = 7.60 +/- 0.41 pb for a top-quark mass of m(t) = 172.5 GeV. The contributions to the uncertainty are 0.20 pb from statistical sources, 0.29 pb from systematic sources, and 0.21 pb from the uncertainty on the integrated luminosity. The result is in good agreement with the standard model expectation of 7.35(-0.33)(+0.28) pb at next-to-next-to-leading order and next-to-next-to leading logarithms in perturbative QCD.
|
|
3. |
- Aaltonen, T., et al.
(författare)
-
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
- 2018
-
Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 120:4
-
Tidskriftsartikel (refereegranskat)abstract
- The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of root s = 1.96 TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A(FB)(t (t) over bar) = 0.128 +/- 0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.
|
|
4. |
- Aaltonen, T., et al.
(författare)
-
Observation of s-Channel Production of Single Top Quarks at the Tevatron
- 2014
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:23
-
Tidskriftsartikel (refereegranskat)abstract
- We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The measured cross section is sigma(s) = 1.29(-0.24)(+0.26) pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 x 10(-10), corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.
|
|
5. |
- Aaltonen, T., et al.
(författare)
-
Tevatron Constraints on Models of the Higgs Boson with Exotic Spin and Parity Using Decays to Bottom-Antibottom Quark Pairs
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:15
-
Tidskriftsartikel (refereegranskat)abstract
- Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value J(P) = 0(+). Both collaborations analyzed approximately 10 fb(-1) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with J(P) = 0(-) and J(P) = 2(+) are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the J(P) = 0(-) hypothesis and the J(P) = 2(+) hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the J(P) = 0(-) and J(P) = 2(+) hypotheses, respectively.
|
|
6. |
- Aaltonen, T., et al.
(författare)
-
Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element V-tb
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:15
-
Tidskriftsartikel (refereegranskat)abstract
- We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The t-channel cross section is measured to be sigma(t) = 2.25(-0.31)(+0.29) pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s + t channel cross section measurement resulting in sigma(s+t) = 3.30(-0.40)(+0.52) pb, without assuming the standard model value for the ratio sigma(s)/sigma(t). The resulting value of the magnitude of the top-to-bottom quark coupling is vertical bar V-tb vertical bar = 1.02(-0.05)(+0.06), corresponding to vertical bar V-tb vertical bar > 0.92 at the 95% C. L.
|
|
7. |
- Abazov, V. M., et al.
(författare)
-
Search for the rare decay B-s(0) -> mu(+) mu(-)
- 2013
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 87:7, s. 072006-
-
Tidskriftsartikel (refereegranskat)abstract
- We perform a search for the rare decay B-s(0) -> mu(+) mu(-) using data collected by the D0 experiment at the Fermilab Tevatron Collider. This result is based on the full D0 Run II data set corresponding to 10.4 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV. We use a multivariate analysis to increase the sensitivity of the search. In the absence of an observed number of events above the expected background, we set an upper limit on the decay branching fraction of B(B-s(0) -> mu(+) mu(-)) < 15 x 10(-9) (12 x 10(-9)) at the 95% (90%) C.L.
|
|
8. |
- Abazov, V. M., et al.
(författare)
-
Study of double parton interactions in diphoton plus dijet events in p<(p)over bar> collisions at root s = 1.96 TeV
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:5
-
Tidskriftsartikel (refereegranskat)abstract
- We use a sample of diphoton + dijet events to measure the effective cross section of double parton interactions, which characterizes the area containing the interacting partons in proton-antiproton collisions, and find it to be sigma(eff) = 19.3 +/- 1.4(stat) +/- 7.8(syst) mb. The sample was collected by the D0 detector at the Fermilab Tevatron collider in p (p) over bar collisions at root s = 1.96 TeV and corresponds to an integrated luminosity of 8.7 fb(-1).
|
|
9. |
- Abazov, V. M., et al.
(författare)
-
B-s(0) lifetime measurement in the CP-odd decay channel B-s(0) -> J/Psi f(0)(980)
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 94:1
-
Tidskriftsartikel (refereegranskat)abstract
- The lifetime of the B-s(0) meson is measured in the decay channel B-s(0) -> J/Psi pi(+)pi(-) with 880 <= M pi+pi- <= 1080 MeV/c(2), which is mainly a CP-odd state and dominated by the f(0)(980) resonance. In 10.4 fb(-1) of data collected with the D0 detector in Run II of the Tevatron, the lifetime of the B-s(0) meson is measured to be tau(B-s(0)) = 1.70 +/- 0.14(stat) +/- 0.05(syst) ps. Neglecting CP violation in B-s(0)/(B) over bar (0)(s) mixing, the measurement can be translated into the width of the heavy mass eigenstate of the B-s(0), Gamma(H) = 0.59 +/- 0.05(stat) +/- 0.02(syst) ps(-1).
|
|
10. |
- Abazov, V. M., et al.
(författare)
-
Combination of D0 measurements of the top quark mass
- 2017
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:11
-
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.
|
|
11. |
- Abazov, V. M., et al.
(författare)
-
Constraints on Models for the Higgs Boson with Exotic Spin and Parity in VH -> Vb(b)over-bar Final States
- 2014
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 113:16, s. 161802-
-
Tidskriftsartikel (refereegranskat)abstract
- We present constraints on models containing non-standard-model values for the spin J and parity P of the Higgs boson H in up to 9.7 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. These are the first studies of Higgs boson J(P) with fermions in the final state. In the ZH -> llb (b) over bar, WH -> l nu b (b) over barb, and ZH -> nu nu b (b) over bar final states, we compare the standard model (SM) Higgs boson prediction, J(P) = 0(+), with two alternative hypotheses, J(P) = 0(-) and J(P) = 2(+). We use a likelihood ratio to quantify the degree to which our data are incompatible with non-SM J(P) predictions for a range of possible production rates. Assuming that the production rate in the signal models considered is equal to the SM prediction, we reject the J(P) = 0(-) and J(P) = 2(+) hypotheses at the 97.6% CL and at the 99.0% CL, respectively. The expected exclusion sensitivity for a J(P) = 0(-)(J(P) = 2(+)) state is at the 99.86% (99.94%) CL. Under the hypothesis that our data are the result of a combination of the SM-like Higgs boson and either a J(P) = 0(-) or a J(P) = 2(+) signal, we exclude a J(P) = 0(-) fraction above 0.80 and a JP = 2(+) fraction above 0.67 at the 95% CL. The expected exclusion covers J(P) = 0(-)(J(P) = 2(+)) fractions above 0.54 (0.47).
|
|
12. |
- Abazov, V. M., et al.
(författare)
-
Double parton interactions in gamma+3 jet and gamma plus b/c jet+2 jet events in p(p)over-bar collisions at root s=1.96 TeV
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:7, s. 072006-
-
Tidskriftsartikel (refereegranskat)abstract
- We determine the fraction of events with double parton (DP) Scattering in a single p (p) over bar collisions at root s = 1.96 TeV in gamma + 3 jet and gamma + b/c jet + 2 jet events collected with the D0 detector and corresponding to an integrated luminosity of about 8.7 fb(-1). The DP fractions and effective cross sections (sigma(eff)) are measured for both event samples using the same kinematic selections. The measured DP fractions range from 0.21 to 0.17, with effective cross sections in the gamma + 3 jet and gamma + b/cjet + 2 jet samples of sigma(incl)(eff) = 12.7 +/- 0.2(stat) +/- 1.3(syst) mb and sigma(HF)(eff) = 14.6 +/- 0.6(stat) +/- 3.2(syst) mb, respectively.
|
|
13. |
- Abazov, V. M., et al.
(författare)
-
Electron and photon identification in the Do experiment
- 2014
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 750, s. 78-95
-
Tidskriftsartikel (refereegranskat)abstract
- The electron and photon reconstruction and identification algorithms used by the DO Collaboration at the Fermilab Tevatron collider are described. The determination of the electron energy scale and resolution is presented. Studies of the performance of the electron and photon reconstruction and identification are summarized. The results are based on measurements of Z boson decay events of Z ee and Z gamma ll(i=e mu) collected in pp(over bar) collisions at a center- of- mass energy of 1.96 TeV using an integrated luminosity of up to10 fb(-1.)
|
|
14. |
- Abazov, V. M., et al.
(författare)
-
Evidence for a B-s(0)pi(+/-) State
- 2016
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 117:2
-
Tidskriftsartikel (refereegranskat)abstract
- We report evidence for a narrow structure, X(5568), in the decay sequence X(5568) -> B-s(0)pi(+/-), B-s(0) -> J/psi phi, J/psi -> mu(+)mu(-), phi -> K+K-. This is evidence for the first instance of a hadronic state with valence quarks of four different flavors. The mass and natural width of this state are measured to be m = 5567.8 +/- 2.9(stat)(-1.9)(+0.9) (syst) MeV/c(2) and Gamma = 21.9 +/- 6.4(stat)(-2.5)(+5.0) (syst) MeV/c(2). If the decay is X(5568) -> B-s*pi(+/-). B-s(0)gamma pi(+/-) with an unseen gamma, m(X(5568)) will be shifted up by m(B-s*) - m(B-s(0)) similar to 49 MeV/c(2). This measurement is based on 10.4 fb(-1) of p (p) over bar collision data at root s = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider.
|
|
15. |
- Abazov, V. M., et al.
(författare)
-
Evidence for Simultaneous Production of J/psi and Upsilon Mesons
- 2016
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 116:8
-
Tidskriftsartikel (refereegranskat)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.
|
|
16. |
- Abazov, V. M., et al.
(författare)
-
Evidence for Z(c)(+/-)(3900) in semi-inclusive decays of b-flavored hadrons
- 2018
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 98:5
-
Tidskriftsartikel (refereegranskat)abstract
- We present evidence for the exotic charged charmoniumlike state Z(c)(+/-)(3900) decaying to J/psi pi(+/-) in semi-inclusive weak decays of b-flavored hadrons. The signal is correlated with a parent J/psi pi(+)pi(-) system in the invariant-mass range 4.2-4.7 GeV that would include the exotic structure Y(4260). The study is based on 10.4 fb(-1) of p (p) over bar collision data collected by the D0 experiment at the Fermilab Tevatron collider.
|
|
17. |
- Abazov, V. M., et al.
(författare)
-
Improved b quark jet identification at the D0 experiment
- 2014
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 763, s. 290-303
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to identify jets which originated from b quarks is an important tool of the physics program of the D0 experiment at the Fermilab Tevatron p (p) over bar collider. This paper describes a new algorithm designed to select jets originating from b quarks while suppressing the contamination caused by jets from other quark flavors and gluons. Additionally, a new technique, the SystemN method, for determining the misidentification rate directly from data is presented. (C) 2014 Elsevier B.V. All rights reserved.
|
|
18. |
- Abazov, V. M., et al.
(författare)
-
Inclusive Production of the X(4140) State in p(p)over-bar Collisions at D0
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:23
-
Tidskriftsartikel (refereegranskat)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.
|
|
19. |
- Abazov, V. M., et al.
(författare)
-
Measurement of differential tt production cross sections in pp collisions
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:9, s. 092006-
-
Tidskriftsartikel (refereegranskat)abstract
- The production of top quark-antiquark pair events in pp collisions at root s= 1.96 TeV is studied as a function of the transverse momentum and absolute value of the rapidity of the top quarks as well as of the invariant mass of the tt pair. We select events containing an isolated lepton, a large imbalance in transverse momentum, and four or more jets with at least one jet identified as originating from a b quark. 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. Observed differential cross sections are consistent with standard model predictions.
|
|
20. |
- Abazov, V. M., et al.
(författare)
-
Measurement of direct CP violation parameters in B-+/- -> J/psi K-+/- and B-+/- -> J/psi pi(+/-) decays with 10.4 fb(-1) of Tevatron data
- 2013
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 110:24, s. 241801-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the direct CP-violating charge asymmetry in B-+/- mesons decaying to J/psi K-+/- and J/psi pi(+/-) where J/psi decays to mu(+)mu(-), using the full run II data set of 10.4 fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B- and B+ mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of A(J/psi K) = [0.59 +/- 0.37]%, which is the most precise measurement to date, and A(J/psi pi) = [-4.2 +/- 4.5]%. Both measurements are consistent with standard model predictions.
|
|
21. |
- Abazov, V. M., et al.
(författare)
-
Measurement of spin correlation between top and antitop quarks produced in p(p)over-bar collisions at root s=1.96 TeV
- 2016
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 757, s. 199-206
-
Tidskriftsartikel (refereegranskat)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.
|
|
22. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the asymmetry in angular distributions of leptons produced in dilepton t(t)over-bar final states in p(p)over-bar collisions at root s=1.96 TeV
- 2013
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:11, s. 112002-
-
Tidskriftsartikel (refereegranskat)abstract
- We present measurements of asymmetries in angular distributions of leptons produced in t (t) over bar events in proton-antiproton collisions at the Fermilab Tevatron Collider. We consider final states where the W-+/- bosons from top quark and antiquark decays both decay into l nu (l = e, mu) resulting in oppositely charged dilepton final states with accompanying jets. Using 9.7 fb(-1) of integrated luminosity collected with the D0 detector, we find the asymmetries in lepton pseudorapidity compatible with predictions based on the standard model.
|
|
23. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the B-s(0) Lifetime in the Flavor-Specific Decay Channel B-s(0)-> D-s(-)mu(+)nu X
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:6
-
Tidskriftsartikel (refereegranskat)abstract
- We present an updated measurement of the B-s(0) lifetime using the semileptonic decays B-s(0) -> D-s(-)mu(+)nu X, with D-s(-) -> phi pi(-) and phi -> K+K- (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at root s = 1.96 TeV, comprising an integrated luminosity of 10.4 fb(-1). We find a flavor-specific lifetime tau(fs)(B-s(0)) = 1.479 +/- 0.010(stat) +/- 0.021(syst) ps. This technique is also used to determine the B-0 lifetime using the analogous B-0 -> D- mu(+)nu X decay with D- -> phi pi(-) and phi -> K+K-, yielding tau(B-0) = 1.534 +/- 0.019(stat) +/- 0.021(syst) ps. Both measurements are consistent with the current world averages, and the B-s(0) lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio tau(fs)(B-s(0))/tau(B-0) = 0.964 +/- 0.013(stat) +/- 0.007(syst).
|
|
24. |
- Abazov, V. M., et al.
(författare)
-
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
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 737, s. 357-365
-
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.
|
|
25. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the direct CP violating charge asymmetry in B-+/- -> mu(+/-)nu D-mu(0) decays
- 2017
-
Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:3
-
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.
|
|
26. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the Direct CP-violating Charge Asymmetry in D-s(+/-) -> Phi pi(+/-) Decays
- 2014
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 112:11, s. 111804-
-
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.
|
|
27. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the direct CP-violating parameter A(CP) in the decay D+ -> K-pi(+)pi(+)
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:11, s. 111102-
-
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.
|
|
28. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the Effective Weak Mixing Angle in p(p)over-bar -> Z/gamma* -> e(+)e(-) Events
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:4
-
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.
|
|
29. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the Effective Weak Mixing Angle in p¯p→Z/γ∗→ℓ+ℓ− Events
- 2018
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 120:24
-
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.
|
|
30. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the electric charge of the top quark in t(t)over-bar events
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:5, s. 051101-
-
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.
|
|
31. |
- Abazov, V. M., et al.
(författare)
-
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
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:3
-
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.
|
|
32. |
|
|
33. |
- Abazov, V. M., et al.
(författare)
-
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
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:7
-
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).
|
|
34. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the forward-backward asymmetry in the distribution of leptons in t(t)over-bar events in the lepton plus jets channel
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:7, s. 072001-
-
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.
|
|
35. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the Forward-Backward Asymmetry in the Production lof B-+/- Mesons in p(p)over-bar Collisions at root s=1.96 TeV
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:5
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the forward-backward asymmetry in the production of B-+/- mesons, A(FB)(B-+/-) using B-+/- -> J/ Psi K-+/- decays in 10.4 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or (b) over bar antiquark, to be produced in the direction of the proton beam. We extract A(FB) (B-+/-) from a maximum likelihood fit to the difference between the numbers of forward-and backward-produced B-+/- mesons. We measure an asymmetry consistent with zero: A(FB) (B-+/-) = [-0.24 +/- 0.41 (stat) +/- 0.19 (syst)] %.
|
|
36. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the forward-backward asymmetry in top quark-antiquark production in p(p)over-bar collisions using the lepton plus jets channel
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:7
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the forward-backward asymmetry in top quark-antiquark production using the full Tevatron Run II data set collected by the D0 experiment at Fermilab. The measurement is performed in lepton + jets final states using a new kinematic fitting algorithm for events with four or more jets and a new partial reconstruction algorithm for events with only three jets. Corrected for detector acceptance and resolution effects, the asymmetry is evaluated to be A(FB) = (10.6 +/- 3.0)%. Results are consistent with the standard model predictions which range from 5.0% to 8.8%. We also present the dependence of the asymmetry on the invariant mass of the top quark-antiquark system and the difference in rapidities of the top quark and antiquark.
|
|
37. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the forward-backward asymmetry of Lambda and (Lambda)over-bar production in p(p)over-bar collisions
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:3
-
Tidskriftsartikel (refereegranskat)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.
|
|
38. |
- Abazov, V. M., et al.
(författare)
-
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
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 94:9
-
Tidskriftsartikel (refereegranskat)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.
|
|
39. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the muon charge asymmetry in p(p)over-bar -> W + X -> mu nu + X events at root s=1.96 TeV
- 2013
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:9, s. 091102-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the muon charge asymmetry from the decay of the W boson via W -> mu nu using 7: 3 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider at root s = 1.96 TeV. The muon charge asymmetry is presented in two kinematic regions in muon transverse momentum and event missing transverse energy: (p(T)(mu) > 25 GeV, E-T > 25 GeV) and (p(T)(mu) > 35 GeV, E-T > 35 GeV). The measured asymmetries are compared with theory predictions made using three parton distribution function sets. The data at p(T)(mu) > 35 GeV, E-T > 35 GeV, and larger values of vertical bar eta(mu)vertical bar favor an increased d(x)/u(x) ratio at higher values of x than is predicted.
|
|
40. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the phi(eta)* distribution of muon pairs with masses between 30 and 500 GeV in 10.4 fb(-1) of p(p)over-bar collisions
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:7
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the distribution of the variable phi(eta)* for muon pairs with masses between 30 and 500 GeV, using the complete run II data set collected by the D0 detector at the Fermilab Tevatron proton-antiproton collider. This corresponds to an integrated luminosity of 10.4 fb(-1) at root s = 1.96 TeV. The data are corrected for detector effects and presented in bins of dimuon rapidity and mass. The variable phi(eta)* probes the same physical effects as the Z/gamma* boson transverse momentum, but is less susceptible to the effects of experimental resolution and efficiency. These are the first measurements at any collider of the phi(eta)* distributions for dilepton masses away from the Z --> l(+)l(-) boson mass peak. The data are compared to QCD predictions based on the resummation of multiple soft gluons.
|
|
41. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the ratio of inclusive cross sections sigma(p(p)over-bar) -> Z+2b jets/sigma(p((p)over-bar) -> Z+2 jets) in p((p)over-bar) collisions at root s=1.96 TeV
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:5
-
Tidskriftsartikel (refereegranskat)abstract
- We measure the ratio of cross sections, σ(pp¯→Z+2b jets)/σ(pp¯→Z+2 jets), for associated production of a Z boson with at least two jets with transverse momentum pjetT>20 GeV and pseudorapidity |ηjet|<2.5. This measurement uses data corresponding to an integrated luminosity of 9.7 fb−1 collected by the D0 experiment in Run II of Fermilab’s Tevatron pp¯ Collider at a center-of-mass energy of 1.96 TeV. The measured integrated ratio of 0.0236±0.0032 (stat)±0.0035 (syst) is in agreement with predictions from next-to-leading-order perturbative QCD and the Monte Carlo event generators pythia and alpgen.
|
|
42. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the top quark mass using the matrix element technique in dilepton final states
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 94:3
-
Tidskriftsartikel (refereegranskat)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.
|
|
43. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the W boson mass with the D0 detector
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:1, s. 012005-
-
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.
|
|
44. |
- Abazov, V. M., et al.
(författare)
-
Measurement of the W plus b-jet and W plus c-jet differential production cross sections in p (p)over-bar collisions at root s=1.96 TeV
- 2015
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 743, s. 6-14
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the cross sections for the associated production of a W boson with at least one heavy quark jet, b or c, in proton-antiproton collisions. Data corresponding to an integrated luminosity of 8.7 fb(-1) recorded with the D0 detector at the Fermilab Tevatron p (p) over bar Collider at root s = 1.96 TeV are used to measure the cross sections differentially as a function of the jet transverse momenta in the range 20 to 150 GeV. These results are compared to calculations of perturbative QCD theory as well as predictions from Monte Carlo generators.
|
|
45. |
- Abazov, V. M., et al.
(författare)
-
Measurement of top quark polarization in t(t)over-bar lepton+jets final states
- 2017
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 95:1
-
Tidskriftsartikel (refereegranskat)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.
|
|
46. |
- Abazov, V. M., et al.
(författare)
-
Observation and studies of double J/psi production at the Tevatron
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:11, s. 111101-
-
Tidskriftsartikel (refereegranskat)abstract
- We present the observation of doubly produced J/psi mesons with the D0 detector at Fermilab in p (p) over bar collisions at root s = 1.96 TeV. The production cross section for both singly and doubly produced J/psi mesons is measured using a sample with an integrated luminosity of 8.1 fb(-1). For the first time, the double J/psi production cross section is separated into contributions due to single and double parton scatterings. Using these measurements, we determine the effective cross section seff, a parameter characterizing an effective spatial area of the parton-parton interactions and related to the parton spatial density inside the nucleon.
|
|
47. |
- Abazov, V. M., et al.
(författare)
-
Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting
- 2016
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 752, s. 18-26
-
Tidskriftsartikel (refereegranskat)abstract
- We measure the top quark mass in dilepton final states of t (t) over bar events in p (p) over bar collisions at root s = 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb(-1) at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. We also improve the calibration of jet energies using the calibration determined in t (t) over bar -> lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured top quark mass is m(t) = 173.32 +/- 1.36(stat) +/- 0.85(syst) GeV.
|
|
48. |
- Abazov, V. M., et al.
(författare)
-
Precision measurement of the top-quark mass in lepton plus jets final states
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:11
-
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 the W boson. We measure m(t) = 174.98 +/- 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass.
|
|
49. |
- Abazov, V. M., et al.
(författare)
-
Precision Measurement of the Top Quark Mass in Lepton plus Jets Final States
- 2014
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 113:3, s. 032002-
-
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.
|
|
50. |
- Abazov, V. M., et al.
(författare)
-
Search for the X(4140) state in B+ -> J/psi phi K+ decays with the D0 detector
- 2014
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:1, s. 012004-
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the decay B+ -> J/psi phi K+ in a search for the X(4140) state, a narrow threshold resonance in the J/psi phi system. The data sample corresponds to an integrated luminosity of 10.4 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider. We observe a mass peak with a statistical significance of 3.1 standard deviations and measure its invariant mass to be M = 4159.0 +/- 4.3(stat) +/- 6.6(syst) MeV and its width to be Gamma = 19.9 +/- 12.6(stat)(-8.0)(+3.0)(syst) MeV.
|
|