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Images of Quark Intrinsic Motion in Covariant Parton Model
We discuss the relations between TMDs and PDFs in the framework of the covariant parton model. The quark OAM and its connection to TMDs are studied as well.
Date:
April 1, 2010
Creator:
A.V. Efremov, P. Schweitzer, O.V. Teryaev, P. Zavada
Object Type:
Article
System:
The UNT Digital Library
Measurement of Z gamma Production in pbar{p} Collisions at sqrt{s} = 1.96 TeV
The production rate and kinematics of photons produced in association with Z bosons are studied using 2 fb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross section for p{bar p} {yields} {ell}{sup +}{ell}{sup -}{gamma} + X (where the leptons {ell} are either muons or electrons with dilepton mass M{sub {ell}{ell}} > 40 GeV/c{sup 2}, and where the photon has transverse energy E{sub T}{sup {gamma}} > 7 GeV and is well separated from the leptons) is 4.6 {+-} 0.2 (stat) {+-} 0.3 (syst) {+-} 0.3 (lum) pb, which is consistent with standard model expectations. We use the photon ET distribution from Z{gamma} events where the Z has decayed to {mu}{sup +}{mu}{sup -}, e{sup +}e{sup -}, or {nu}{bar {nu}} to set limits on anomalous (non-standard-model) trilinear couplings between photons and Z bosons.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Observation of Single Top Quark Production and Measurement of |Vtb| with CDF
We report the observation of electroweak single top quark production in 3.2 fb{sup -1} of p{bar p} collision data collected by the Collider Detector at Fermilab at {radical}s = 1.96 TeV. Candidate events in the W+jets topology with a leptonically decaying W boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of 2.3{sub -0.5}{sup +0.6}(stat + sys) pb, extract the CKM matrix element value |V{sub tb}| = 0.91{sub -0.11}{sup +0.11}(stat + sys) {+-} 0.07(theory), and set a lower limit |V{sub tb}| > 0.71 at the 95% confidence level, assuming m{sub t} = 175 GeV/c{sup 2}.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type:
Article
System:
The UNT Digital Library
First Measurement of the Ratio sigma_(t-tbar) / sigma_(Z/\gamma*->ll) and Precise Extraction of the t-tbar Cross Section
We report a measurement of the ratio of the t{bar t} to Z/{gamma}* production cross sections in {radical}s = 1.96 TeV p{bar p} collisions using data corresponding to an integrated luminosity of up to 4.6 fb{sup -1}, collected by the CDF II detector. The t{bar t} cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/{gamma}* {yields} ll cross section predicted by the standard model, the extracted t{bar t} cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result {sigma}{sub t{bar t}} = 7.70 {+-} 0.52 pb, for a top-quark mass of 172.5 GeV/c{sup 2}.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the $B^-$ lifetime using a simulation free approach for trigger bias correction
The collection of a large number of B hadron decays to hadronic final states at the CDF II detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection requirements of the trigger introduces a large bias in the observed proper decay time distribution. A lifetime measurement must correct for this bias and the conventional approach has been to use a Monte Carlo simulation. The leading sources of systematic uncertainty in the conventional approach are due to differences between the data and the Monte Carlo simulation. In this paper they present an analytic method for bias correction without using simulation, thereby removing any uncertainty between data and simulation. This method is presented in the form of a measurement of the lifetime of the B{sup -} using the mode B{sup -} {yields} D{sup 0}{pi}{sup -}. The B{sup -} lifetime is measured as {tau}{sub B{sup -}} = 1.663 {+-} 0.023 {+-} 0.015 ps, where the first uncertainty is statistical and the second systematic. This new method results in a smaller systematic uncertainty in comparison to methods that use simulation to correct for the trigger bias.
Date:
April 1, 2010
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type:
Article
System:
The UNT Digital Library
Search for Randall-Sundrum gravitons in the dielectron and diphoton final states with 5.4fb$^{-1}$ of data from $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
Using 5.4 fb{sup -1} of integrated luminosity from p{bar p} collisions at {radical}s = 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider, we search for decays of the lightest Kaluza-Klein mode of the graviton in the Randall-Sundrum model to ee and {gamma}{gamma}. We set 95% C.L. lower limits on the mass of the lightest graviton between 560 GeV and 1050 GeV for values of the coupling k/{bar M}{sub Pl} between 0.01 and 0.1.
Date:
April 1, 2010
Creator:
Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; U., /Oklahoma; Abolins, Maris A.; U., /Michigan State et al.
Object Type:
Article
System:
The UNT Digital Library
Doctoral Recital: 2010-04-26 - Armin Abdihodzic, guitar
Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date:
April 26, 2010
Creator:
Abdihodzic, Armin
Object Type:
Sound
System:
The UNT Digital Library
Abraham Lincoln Bicentennial Commission: Final Report to Congress and the American People
Final report of the Abraham Lincoln Bicentennial Commission describing its activities commemorating the 200th birthday of America's 16th president.
Date:
April 2010
Creator:
Abraham Lincoln Bicentennial Commission
Object Type:
Report
System:
The UNT Digital Library
Solute Descriptors for Phenoxide Anions and Their Use to Establish Correlations of Rates of Reaction of Anions with Iodomethane
Article on solute descriptors for phenoxide anions and their use to establish correlations of rates of reaction of anions with iodomethane.
Date:
April 9, 2010
Creator:
Abraham, M. H. (Michael H.) & Acree, William E. (William Eugene)
Object Type:
Article
System:
The UNT Digital Library
Next Generation Bipolar Plates for Automotive PEM Fuel Cells
The results of a successful U.S. Department of Energy (DoE) funded two-year $2.9 MM program lead by GrafTech International Inc. (GrafTech) are reported and summarized. The program goal was to develop the next generation of high temperature proton exchange membrane (PEM) fuel cell bipolar plates for use in transportation fuel cell applications operating at temperatures up to 120 °C. The bipolar plate composite developed during the program is based on GrafTech’s GRAFCELL resin impregnated flexible graphite technology and makes use of a high temperature Huntsman Advanced Materials resin system which extends the upper use temperature of the composite to the DoE target. High temperature performance of the new composite is achieved with the added benefit of improvements in strength, modulus, and dimensional stability over the incumbent resin systems. Other physical properties, including thermal and electrical conductivity of the new composite are identical to or not adversely affected by the new resin system. Using the new bipolar plate composite system, machined plates were fabricated and tested in high temperature single-cell fuel cells operating at 120 °C for over 1100 hours by Case Western Reserve University. Final verification of performance was done on embossed full-size plates which were fabricated and glued into …
Date:
April 15, 2010
Creator:
Adrianowycz, Orest; Norley, Julian; Stuart, David J.; Flaherty, David; Wayne, Ryan; Williams, Warren et al.
Object Type:
Report
System:
The UNT Digital Library
A Dual Channel X-ray Spectrometer for Fast Ignition Research
A new Dual Channel Highly Ordered Pyrolytic Graphite (DC-HOPG) x-ray spectrometer was developed to study laser-generated electron beam transport. The instrument uses a pair of graphite crystals and has the advantage of simultaneously detecting self emission from low-Z materials in first diffraction order and high-Z materials in second order. The emissions from the target are detected using a pair of parallel imaging plates positioned in a such way that the noise from background is minimized and the mosaic focusing is achieved. Initial tests of the diagnostic on Titan laser (I {approx} 10{sup 20} W/cm{sup 2}, {tau} = 0.7 ps) show excellent signal-to-noise ratio (SNR) > 1000 for the low energy channel and SNR > 400 for the high energy channel.
Date:
April 19, 2010
Creator:
Akli, K. U.; Patel, P. K.; Van Maren, R.; Stephens, R. B.; Key, M. H.; Higginson, D. P. et al.
Object Type:
Article
System:
The UNT Digital Library
Laser-Wakefield driven compact Compton scattering gamma-ray source
None
Date:
April 13, 2010
Creator:
Albert, F.; Froula, D. H.; Hartemann, F. V. & Joshi, C.
Object Type:
Report
System:
The UNT Digital Library
Ergonomics in the Biosciences
None
Date:
April 12, 2010
Creator:
Alexandre, Melanie
Object Type:
Report
System:
The UNT Digital Library
Helium measurements of pore-fluids obtained from SAFOD drillcore
{sup 4}He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk {sup 4}He diffusion coefficient of 3.5 {+-} 1.3 x 10{sup -8} cm{sup 2}s{sup -1} at 21 C, compared to previously published diffusion coefficients of 1.2 x 10{sup -18} cm{sup 2}s{sup -1} (21 C) to 3.0 x 10{sup -15} cm{sup 2}s{sup -1} (150 C) in the sands and clays. Correcting the diffusion coefficient of {sup 4}He{sub water} for matrix porosity ({approx}3%) and tortuosity ({approx}6-13) produces effective diffusion coefficients of 1 x 10{sup -8} cm{sup 2}s{sup -1} (21 C) and 1 x 10{sup -7} (120 C), effectively isolating pore fluid {sup 4}He from the {sup 4}He contained in the rock matrix. Model calculations indicate that <6% of helium initially …
Date:
April 15, 2010
Creator:
Ali, S.; Stute, M.; Torgersen, T.; Winckler, G. & Kennedy, B.M.
Object Type:
Article
System:
The UNT Digital Library
The FERMI@Elettra free-electron-laser source for coherent X-ray physics: photon properties, beam transport system, and applications
FERMI@Elettra is comprised of two free electron lasers (FELs) that will generate short pulses (tau ~;; 25 to 200 fs) of highly coherent radiation in the XUV and soft X-ray region. The use of external laser seeding together with a harmonic upshift scheme to obtain short wavelengths will give FERMI@Elettra the capability to produce high quality, longitudinal coherent photon pulses. This capability together with the possibilities of temporal synchronization to external lasers and control of the output photon polarization will open new experimental opportunities not possible with currently available FELs. Here we report on the predicted radiation coherence properties and important configuration details of the photon beam transport system. We discuss the several experimental stations that will be available during initial operations in 2011, and we give a scientific perspective on possible experiments that can exploit the critical parameters of this new light source.
Date:
April 5, 2010
Creator:
Allaria, Enrico; Callegari, Carlo; Cocco, Daniele; Fawley, William M.; Kiskinova, Maya; Masciovecchio, Claudio et al.
Object Type:
Article
System:
The UNT Digital Library
E85 Quality Specifications and Market Surveys
Presentation about ethanol, specifications for E85, and market surveys of fuel quality.
Date:
April 20, 2010
Creator:
Alleman, T. L.
Object Type:
Presentation
System:
The UNT Digital Library
Doctoral Recital: 2010-04-13 - Reuben Allred, piano
Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date:
April 13, 2010
Creator:
Allred, Reuben
Object Type:
Sound
System:
The UNT Digital Library
The Universal Code
Poster presentation for the 2010 University Scholars Day at the University of North Texas discussing research on the universal code.
Date:
April 15, 2010
Creator:
Alvarado, Roberto & Kirk, Andrea B.
Object Type:
Poster
System:
The UNT Digital Library
Southwest Retort, Volume 62, Number 8, April 2010
This publication of the Dallas-Fort Worth Section of the American Chemical Society includes information about research, prominent scientist, organizational business, and various other stories of interest to the community.
Date:
April 2010
Creator:
American Chemical Society. Dallas/Fort Worth Section.
Object Type:
Journal/Magazine/Newsletter
System:
The UNT Digital Library
Polls on the Environment and Global Warming
This report is a meta-analysis of twenty years of public opinion polls about Americans views on environmental quality, environmental policy, and environmental science.
Date:
April 2010
Creator:
American Enterprise Institute for Public Policy Research
Object Type:
Text
System:
The UNT Digital Library
A search for $ZH\rightarrow \mu\mu b \bar{b}$ production at the Tevatron
The Standard Model describes with a very good accuracy all interactions of the, so far, known elementary particles. However the Higgs mechanism, which gives rise to the observed mass of these particles, has not yet been confirmed. The Higgs particle has not yet been observed, and the observation or exclusion is an important test of the Standard Model. The Standard Model does not predict the mass of the Higgs particle, however it does impose some limits on the range in which this mass can lie. In direct searches a Higgs with a mass smaller than 114.4 GeV and within 162 GeV and 166 GeV has been excluded at 95% CL at the LEP and the Tevatron colliders. The analysis presented in this thesis is aimed to search for the ZH → μμb$\bar{b}$ events in 3.1 fb<sup>-1</sup> of data collected with the DØ detector in p$\bar{p}$ collisions at √s = 1.96 TeV.
Date:
April 20, 2010
Creator:
Ancu, Lucian-Stefan
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Muon-induced backgrounds in the CUORICINO experiment
To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.
Date:
April 15, 2010
Creator:
Andreotti, E.; Arnaboldi, C.; Avignone, F. T. III; Balata, M.; Bandac, I.; Barucci, M. et al.
Object Type:
Article
System:
The UNT Digital Library
Oral History Interview with Daniel Andrews, April 13, 2010
The National Museum of the Pacific War presents an oral interview with Daniel Andrews. Andrews joined the United States Navy in 1941 where he became a SeaBee. Andrews was sent to Saipan to help build airfields and seaplane bases. He left Saipan in July of 1945.
Date:
April 13, 2010
Creator:
Andrews, Daniel
Object Type:
Sound
System:
The Portal to Texas History
Oral History Interview with Daniel Andrews, April 13, 2010
The National Museum of the Pacific War presents an oral interview with Daniel Andrews. Andrews joined the United States Navy in 1941 where he became a SeaBee. Andrews was sent to Saipan to help build airfields and seaplane bases. He left Saipan in July of 1945.
Date:
April 13, 2010
Creator:
Andrews, Daniel
Object Type:
Text
System:
The Portal to Texas History