We describe an analysis comparing the pp elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in p p collisions as measured by the TOTEM ...Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of √ s = 1.96 TeV , are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the p p cross section. The two data sets disagree at the 3.4 σ level and thus provide evidence for the t -channel exchange of a colorless, C -odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C -odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in p p scattering for which the significance is between 3.4 σ and 4.6 σ . The combined significance is larger than 5 σ and is interpreted as the first observation of the exchange of a colorless, C -odd gluonic compound.
We present a study of the normalized transverse momentum distribution of W bosons produced in pp collisions, using data corresponding to an integrated luminosity of 4.35 fb−1 collected with the D0 ...detector at the Fermilab Tevatron collider at √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 study the production of the exotic charged charmoniumlike state Zc±(3900) in pp¯ collisions through the sequential process ψ(4260) → Zc±(3900)π∓, Zc±(3900) → J/ψπ±. Using the subsample of ...candidates originating from semi-inclusive weak decays of b-flavored hadrons, we measure the invariant mass and natural width to be M = 3902.6−5.0+5.2(stat)−1.4+3.3(syst) MeV and Γ = 32−21+28(stat)−7+26(syst) MeV, respectively. We search for prompt production of the Zc±(3900) through the same sequential process. No significant signal is observed, and we set an upper limit of 0.70 at the 95% credibility level on the ratio of prompt production to the production via b-hadron decays. 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 effective weak mixing angle parameter sin2θℓeff in pp → 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 pp → 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.
The inclusive cross section of top quark-antiquark pairs produced in pp¯ collisions at 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 σtt¯=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 mt=172.8±1.1(theo)−3.1+3.3(exp) GeV.
We present the observation of doubly-produced $J/\psi$ mesons with the D0 detector at Fermilab in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ 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 \sigteff, a parameter characterizing an effective spatial area of the parton-parton interactions and related to the parton spatial density inside the nucleon.
Here, we report evidence for a narrow structure, X(5568), in the decay sequence X(5568)→$B_s^0 \pi^\pm$, B$_s^0$ →J/ψΦ, J/ψ→μ+μ-, Φ→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) $+0.9\atop{-1.9}$ (syst) MeV/c2 and Γ=21.9±6.4(stat)$+5.0\atop{-2.5}$ (syst) MeV/c2. If the decay is X(5568)→B$*\atop{s}$ π±→B$0\atop{s}$ γπ± with an unseen γ, m(X(5568)) will be shifted up by m(B$*\atop{s}$ )-m(B$0\atop{s}$)~49 MeV/c2. This measurement is based on 10.4 fb-1 of $p\bar{p}$ collision data at $\sqrt{s}$ =1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider.
Here, the lifetime of the Bs0 meson is measured in the decay channel Bs0→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 Bs0 meson is measured to be τ(Bs0) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in Bs0/$\bar{B}$0s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the Bs0, ΓH = 0.59 ± 0.05(stat) ± 0.02(syst) ps-1.
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