1,135 research outputs found
Inclusive production of the state in collisions at D0
We present a study of the inclusive production of the with the
decay to the final state in hadronic collisions. Based on
of collision data collected by the D0
experiment at the Fermilab Tevatron collider, we report the first evidence for
the prompt production of and find the fraction of events
originating from hadrons to be . The ratio of the non-prompt
production rate to the yield in the same channel is . The values of the
mass ~MeV
and width ~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 production at the Tevatron
We present a simultaneous measurement of the forward-backward asymmetry and
the top-quark polarization in production in dilepton final states
using 9.7 fb of proton-antiproton collisions at 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 kinematic configurations. After accounting for the presence
of background events and for calibration effects, we obtain a forward-backward
asymmetry of and a top-quark polarization times spin analyzing power in the beam
basis of ,
with a correlation of 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 If we constrain the top polarization to its
expected standard model value, we measure a forward-backward asymmetry of
A
combination with the D0 measurement in the lepton+jets final
state yields an asymmetry of 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
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.
Some Guidelines For Using Nonparametric Methods For Modeling Data From Response Surface Designs
Traditional response surface methodology focuses on modeling responses using parametric models with designs chosen to balance cost with adequate estimation of parameters and prediction in the design space. Using nonparametric smoothing to approximate the response surface offers both opportunities as well as problems. This article explores some conditions under which these methods can be appropriately used to increase the flexibility of surfaces modeled. The Box and Draper (1987) printing ink study is considered to illustrate the methods
The D0 Run IIb Luminosity Measurement
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
Bioremediation and Leaching Potential of Pentachlorophenol (PCP) in Biodiesel Versus Diesel Carriers
Biodiesel is believed to be more environmentally friendly than petroleum-based diesel when used as a carrier for impregnating wood products with pentachlorophenol (PCP) for decay protection. A 6-mo study was conducted to evaluate bioremediation of PCP in biodiesel vs diesel in soil. Different percentages of biodiesel, diesel, and PCP were mixed with clean soil from a forested site and tested. Samples were taken bimonthly and analyzed for oil and grease, PCP concentration, and microbial enumeration. Soil moisture content was adjusted twice weekly if needed. In addition, toxicity and toxicity characteristic leaching potential were measured at Days 0 and 180. Results showed that with an increase in percentage of biodiesel, there was an increase in degradation of diesel and diesel-amended PCP. The greatest decrease of PCP concentration and toxicity occurred in biodiesel alone by Day 180. Results also showed a significant decrease with time in oil and grease concentration, PCP concentration, and toxicity among different treatments. Based on this study, it appears that the cometabolic effect of biodiesel on micro-organisms could accelerate degradation of PCP in treated wood after disposal
Combination of D0 measurements of the top quark mass
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 TeV and Run II (2001--2011) at
TeV of the Tevatron collider, corresponding to
integrated luminosities of 0.1 fb and 9.7 fb, respectively. The
combined result is: .Comment: 12 pages, 2 figure, published in Phys. Rev.
Corn Stover Availability and Collection Efficiency Using Typical Hay Equipment
Corn stover has been identified as a potential feedstock for the production of fermentable sugars and thermochemical processes. The availability and efficiency of typical hay equipment for collecting corn stover has not been well quantified. Corn stover was collected for two years on a central Kentucky farm near Louisville. Six different harvesting treatments, using traditional hay equipment, were used to harvest corn stover. A rotary mower, rotary scythe (flail-type mower with windrow-forming shields), parallel bar rake, and a round baler were utilized. The average stover moisture content prior to grain harvest was above 40%, and field drying was required before baling. All treatments were analyzed for collection efficiency and corn stover yield. The stover collection yields varied from 1.93 to 5.34 dry t/ha, with collection efficiencies (ratio of stover collected to the total above-ground stover excluding grain) between 32.1% and 94.5%. The most promising collection strategy was disengaging the straw chopper and spreader to produce a windrow behind the combine. This windrow could then be baled in a separate operation that resulted in a collection efficiency of 74.1%
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
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 √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 Att(FB) = 0.128 ± 0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions
Anomaly Detection for Vision-based Railway Inspection
none7nomixedRiccardo Gasparini; Stefano Pini; Guido Borghi; Giuseppe Scaglione; Simone Calderara; Eugenio Fedeli; Rita CucchiaraRiccardo Gasparini; Stefano Pini; Guido Borghi; Giuseppe Scaglione; Simone Calderara; Eugenio Fedeli; Rita Cucchiar
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