1,153 research outputs found

    Inclusive production of the X(4140)X(4140) state in pp‾p \overline p collisions at D0

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    We present a study of the inclusive production of the X(4140)X(4140) with the decay to the J/ψϕJ/\psi \phi final state in hadronic collisions. Based on 10.4 fb−110.4~\rm{fb^{-1}} of pp‾p \overline p collision data collected by the D0 experiment at the Fermilab Tevatron collider, we report the first evidence for the prompt production of X(4140)X(4140) and find the fraction of X(4140)X(4140) events originating from bb hadrons to be fb=0.39±0.07 (stat)±0.10 (syst)f_b=0.39\pm 0.07 {\rm \thinspace (stat)} \pm 0.10 {\rm \thinspace (syst)} . The ratio of the non-prompt X(4140)X(4140) production rate to the Bs0B_s^0 yield in the same channel is R=0.19±0.05 (stat)±0.07 (syst)R=0.19 \pm 0.05 {\rm \thinspace (stat)} \pm 0.07 {\rm \thinspace (syst)}. The values of the mass M=4152.5±1.7(stat)−5.4+6.2 (syst)M=4152.5 \pm 1.7 (\rm {stat}) ^{+6.2}_{-5.4} {\rm \thinspace (syst)}~MeV and width Γ=16.3±5.6 (stat)±11.4 (syst)\Gamma=16.3 \pm 5.6 {\rm \thinspace (stat)} \pm 11.4 {\rm \thinspace (syst)}~MeV are consistent with previous measurements. 8 pages, 2 figuesComment: Submitted to PRL. * pages, 2 figure

    Simultaneous measurement of forward-backward asymmetry and top polarization in dilepton final states from ttˉt\bar t production at the Tevatron

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    We present a simultaneous measurement of the forward-backward asymmetry and the top-quark polarization in ttˉt\bar t production in dilepton final states using 9.7 fb−1^{-1} of proton-antiproton collisions at s=1.96\sqrt{s}=1.96 TeV with the D0 detector. To reconstruct the distributions of kinematic observables we employ a matrix element technique that calculates the likelihood of the possible ttˉt\bar t kinematic configurations. After accounting for the presence of background events and for calibration effects, we obtain a forward-backward asymmetry of Attˉ=(15.0±6.4 (stat)±4.9 (syst))%A^{t\bar t} = (15.0 \pm 6.4 \text{ (stat)} \pm 4.9 \text{ (syst)})\% and a top-quark polarization times spin analyzing power in the beam basis of κP=(7.2±10.5 (stat)±4.2 (syst))%\kappa P = (7.2 \pm 10.5 \text{ (stat)} \pm 4.2 \text{ (syst)})\%, with a correlation of −56%-56\% between the measurements. If we constrain the forward-backward asymmetry to its expected standard model value, we obtain a measurement of the top polarization of κP=(11.3±9.1 (stat)±1.9 (syst))%.\kappa P = (11.3 \pm 9.1 \text{ (stat)} \pm 1.9 \text{ (syst)})\%. If we constrain the top polarization to its expected standard model value, we measure a forward-backward asymmetry of Attˉ=(17.5±5.6 (stat)±3.1 (syst))%.A^{t\bar t} = (17.5 \pm 5.6 \text{ (stat)} \pm 3.1 \text{ (syst)})\%. A combination with the D0 AttˉA^{t\bar t} measurement in the lepton+jets final state yields an asymmetry of Attˉ=(11.8±2.5 (stat)±1.3 (syst))%. A^{t\bar t} = (11.8 \pm 2.5 \text{ (stat)} \pm 1.3 \text{ (syst)})\% . Within their respective uncertainties, all these results are consistent with the standard model expectations.Comment: 16 pages, 16 figures, published versio

    Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

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    We measure the top quark mass in dilepton final states of top-antitop events in proton-antiproton collisions at sqrt(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 top-antitop to lepton+jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured top quark mass is mt = 173.32 +/- 1.36(stat) +/- 0.85(syst) GeV.Comment: 10 pages, 2 figures, 2 tables, subm. to Phys. Lett.

    Fertilizer inspection and analysis, spring, 1949

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    Fertilizer inspection and analysis, fall 1948

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    Fertilizer inspection and analysis, spring 1948

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    Teamwork Makes the Dream Work: Using Team-Based Learning in the Science Classroom

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    With an overwhelming amount of research and a demand for collaborative learning in the classroom, teachers are tackling challenges at all educational levels that often accompany the social aspects of group work. Team-Based Learning (TBL) is an instructional sequence that shifts instruction from teacher lecture to small-group learning. Through the use of teams and social learning, students are actively engaged and learning through critical-thinking tasks. College students can take responsibility both for their own learning and for each other as learners and fellow human beings. TBL allows the instructors to design opportunities for students to demonstrate what they know and can do in the classroom with the content. This study qualitatively examines students’ perceptions of the pedagogical strategy TBL in an undergraduate science course. TBL practices enabled instructors to prepare students for classes in advance and assist students in deeply learning the material through application of course concepts, allowing them to solve interesting, complex, and real-world problems that are relevant to the teaching profession

    Economics of pasture-based dairies (2012)

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    "Agriculture.""Dairy grazing.""Dairy grazing publication series: This publication is one in a series about operating and managing a pasture-based dairy. Although these publications often refer to conditions in Missouri, many of the principles and concepts described may apply to operations throughout the United States. A list of the publications in this series is available online at http://extension.missouri.edu/m168.""Revised from M168, Dairy Grazing Manual, by Joe Horner, Dairy Economist, Commercial Agriculture Program, Ryan Milhollin, Project Manager, Commercial Agriculture Program, Wayne Prewitt, West Central Region Agriculture Business Specialist.""This publication replaces Chapter 14, Economics of a Pasture-Based Dairy, in MU Extension publication M168, Dairy Grazing Manual. Original authors: Stacey A. Hamilton, Greg J. Bishop-Hurley and Ron Young, University of Missouri."New 2/12/Web

    The D0 Run IIb Luminosity Measurement

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    An assessment of the recorded integrated luminosity is presented for data collected with the D0 detector at the Fermilab Tevatron Collider from June 2006 to September 2011 (Run IIb). In addition, a measurement of the effective cross section for inelastic interactions, also referred to as the luminosity constant, is reported. This measurement incorporates new features that lead to a substantial improvement in the precision of the result. A luminosity constant of \sigma_{LM} = 48.3\pm1.9\pm0.6 mb is obtained, where the first uncertainty is due to the accuracy of the inelastic cross section used by both CDF and D0, and the second uncertainty is due to D0 sources. The recorded luminosity for the highest E_T jet trigger is L_rec = 9.2 \pm 0.4 fb^{-1}, with a relative uncertainty of 4.3%.Comment: 20 pages, 23 figure
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