Here, we present evidence for the exotic charged charmoniumlike state Z±c(3900) decaying to J/ψπ± in semi-inclusive weak decays of b-flavored hadrons. The signal is correlated with a parent J/ψπ+π- ...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 pp¯ collision data collected by the D0 experiment at the Fermilab Tevatron collider.
We present the first search for CPT-violating effects in the mixing of B0s mesons 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. We measure the CPT-violating asymmetry in the decay B0s → µ±D±s as a function of celestial direction and sidereal phase. We find no evidence for CPT-violating effects and place limits on the direction and magnitude of flavor-dependent CPTand Lorentz-invariance violating coupling coefficients. We find 95% confidence intervals of Δa⊥ < 1.2 × 10-12 GeV and (-0.8 < ΔaT - 0.396ΔaZ < 3.9) × 10-13 GeV.
Data recorded by the D0 experiment at the Fermilab Tevatron Collider are analyzed to search for neutral Higgs bosons produced in association with b quarks. The search is performed in the ...three-b-quark channel using multijet-triggered events corresponding to an integrated luminosity of 5.2 fb−1. In the absence of any significant excess above background, limits are set on the cross section multiplied by the branching ratio in the Higgs boson mass range 90 to 300 GeV, extending the excluded regions in the parameter space of the minimal supersymmetric standard model.
Here, we present a measurement of the effective weak mixing angle parameter sin2θℓeff in $p\bar{p}$ → Z/γ* → μ+μ– 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 sin2θℓeffμμ = 0.23016 ± 0.00064 is further combined with the result from the D0 measurement in $p\bar{p}$ → Z/γ* → e+e– events, resulting in sin2θℓeffcomb = 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/γ* to light quarks.
We present a measurement of the effective weak mixing angle parameter sin2θ$^{ℓ}_{eff}$ in $p$$\bar{p}$ → Z/γ* → μ+μ- events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at ...the Fermilab Tevatron Collider and corresponding to 8.6 fb-1 of integrated luminosity. The measured value of sin2θ$^{ℓ}_{eff}$ μμ = 0.23016 ± 0.00064 is further combined with the result from the D0 measurement in $p$$\bar{p}$ → Z/γ* → e+ e- events, resulting in sin2θ$^{ℓ}_{eff}$ 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/γ* to light quarks.
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 pp¯ collider. The results are presented as ...differential distributions of the photon pair invariant mass dσ/dMγγ, pair transverse momentum dσ/dpTγγ, azimuthal angle between the photons dσ/dΔϕγγ, and polar scattering angle in the Collins–Soper frame dσ/d|cosθ⁎|. Measurements are performed for isolated photons with transverse momenta pTγ>18(17) GeV for the leading (next-to-leading) photon in pT, pseudorapidities |ηγ|<0.9, and a separation in η–ϕ space ΔRγγ>0.4. We present comparisons with the predictions from Monte Carlo event generators diphox and resbos implementing QCD calculations at next-to-leading order, 2γnnlo at next-to-next-to-leading order, and sherpa using matrix elements with higher-order real emissions matched to parton shower.
We present a measurement of the a production cross section sigma((u) over bar) in p (p) over bar collisions at root s = 1.96 TeV using 5.4 fb(-1) of integrated luminosity collected with the D0 ...detector. We consider final states with at least two jets and two leptons (ee, e mu, mu mu), and events with one jet for the e mu final state as well. The measured cross section is sigma((u) over bar) = 7.36(-0.79)(+0.90)(stat + syst) pb. This result combined with the cross section measurement in the lepton + jets final state yields sigma((u) over bar) = 7.56(-0.56)(+0.63)(stat + syst) pb, which agrees with the standard model expectation. The relative precision of 8% of this measurement is comparable to the precision of the latest theoretical calculations. (C) 2011 Elsevier B.V. All rights reserved.
Here, we present a study of the X±(5568) using semileptonic decays of the Bs0 meson using the full run II integrated luminosity of 10.4 fb-1 in proton-antiproton collisions at a center of mass energy ...of 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. We report evidence for a narrow structure, X±(5568), in the decay sequence X±(5568) → Bs0π± where Bs0 → μ∓Ds±X, Ds± → Φπ± which is consistent with the previous measurement by the D0 Collaboration in the hadronic decay mode, X±(5568) → Bs0π± where Bs0 → J/ψΦ. The mass and width of this state are measured using a combined fit of the hadronic and semileptonic data, yielding m = 5566.9-3.1+3.2(stat)-1.2+0.6(syst) MeV/c2, Γ = 18.6-6.1+7.9(stat)-3.8+3.5(syst) MeV/c2 with a significance of 6.7σ.
We report a measurement of the mass of the top quark in lepton+jets final states of pp → tt̄ data corresponding to 2.6 fb-1 of integrated luminosity collected at the D0 experiment at the Fermilab ...Tevatron Collider. Using a matrix element method, we combine an in situ jet energy calibration with the standard jet energy scale derived in studies of Γ + jet and dijet events and employ a novel flavor-dependent jet response correction to measure a top-quark mass of mt = 176.01 ± 1.64 GeV. Combining this result with a previous result obtained on an independent data set, we measure a top-quark mass of mt = 174.94 ± 1.49 GeV for a total integrated luminosity of 3.6 fb-1.
We present a study of the X±(5568) using semileptonic decays of the Bs0 meson using the full run II integrated luminosity of 10.4 fb−1 in proton-antiproton collisions at a center of mass energy of ...1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. We report evidence for a narrow structure, X±(5568), in the decay sequence X±(5568)→Bs0π± where Bs0→μ∓Ds±X, Ds±→ϕπ± which is consistent with the previous measurement by the D0 Collaboration in the hadronic decay mode, X±(5568)→Bs0π± where Bs0→J/ψϕ. The mass and width of this state are measured using a combined fit of the hadronic and semileptonic data, yielding m=5566.9−3.1+3.2(stat)−1.2+0.6(syst) MeV/c2, Γ=18.6−6.1+7.9(stat)−3.8+3.5(syst) MeV/c2 with a significance of 6.7σ.
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