We present evidence for the exotic charged charmoniumlike state Zc±(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 a measurement of the W boson production charge asymmetry in p$\bar{p}$→W+X→eν+X events at a center of mass energy of 1.96 TeV, using 9.7 fb-1 of integrated luminosity collected with the D0 ...detector at the Fermilab Tevatron Collider. The neutrino longitudinal momentum is determined by using a neutrino weighting method, and the asymmetry is measured as a function of the W boson rapidity. The measurement extends over wider electron pseudorapidity region than previous results and is the most precise to date, allowing for precise determination of proton parton distribution functions in global fits.
We present a study of the normalized transverse momentum distribution of W bosons produced in $p\bar{p}$ collisions, using data corresponding to an integrated luminosity of 4.35 fb-1 collected with ...the D0 detector at the Fermilab Tevatron collider at $\sqrt{s}$ = 1.96 TeV. The measurement focuses on the transverse momentum region below 15 GeV, which is of special interest for electroweak precision measurements; it relies on the same detector calibration methods which were used for the precision measurement of the W boson mass. The measured distribution is compared to different QCD predictions and a procedure is given to allow the comparison of any further theoretical models to the D0 data.
We present a measurement of top quark polarization in tt¯ pair production in pp¯ collisions at 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 tt¯ 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 tt¯ production. The observed distributions are consistent with standard model predictions of nearly no polarization.
Here, the lifetime of the B$0\atop{S}$ meson is measured in the decay channel B$0\atop{S}$→J/ψπ+π- with 880 ≤ Mπ+π- ≤ 1080 MeV/c2, which is mainly a CP-odd state and dominated by the f0(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$0\atop{S}$ meson is measured to be τ(B$0\atop{S}$) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in B$0\atop{S}/$\bar{B}$0s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the B$0\atop{S}$, ΓH = 0.59 ± 0.05(stat) ± 0.02(syst) ps-1.
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 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 present the first measurement of the CP violating charge asymmetry in B±→μ±νμD0 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 AμD0=−0.14±0.20%, which is consistent with standard model predictions.
The muon system of the Run II DØ detector Abazov, V.M.; Alkhazov, G.; Baldin, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2005, Letnik:
552, Številka:
3
Journal Article
Recenzirano
We describe the design, construction, and performance of the upgraded DØ
muon system for Run II of the Fermilab Tevatron collider. Significant improvements have been made to the major subsystems of ...the DØ
muon detector: trigger scintillation counters, tracking detectors, and electronics. The Run II central muon detector has a new scintillation counter system inside the iron toroid and an improved scintillation counter system outside the iron toroid. In the forward region, new scintillation counter and tracking systems have been installed. Extensive shielding has been added in the forward region. A large fraction of the muon system electronics is also new.
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