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2,075 Matching Results

Start Over Decade 2000-2009 Month December Day 1st Language English

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Results: 1 - 24 of 2,075 next
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Editing Tips for Technical Publications in the Joint Nuclear Weapons Publication System (JNWPS) (open access)

Editing Tips for Technical Publications in the Joint Nuclear Weapons Publication System (JNWPS)

These editing tips contain helpful suggestions to assist writers who are writing, editing, and publishing technical publications in the JNWPS. The suggestions clarify some of the most common writing problems and requirements of two publications used in the JNWPS: ''DOE-DTRA TP 1-1, Joint Nuclear Weapons Publications System Operating Procedures, Specifications, and Standards, and United States Government Printing Office Style Manual''. Topics include requirements for abbreviations, formats for drafts, layouts of illustrations and tables, appropriate wording for interim changes, guidance for creating a list of effective pages, how to insert and delete pages and paragraphs, referencing other technical publications, use of revision bars, requirements for safety precautions, use of hyphens, and how to place warnings, cautions, and notes. Also included are a writer's checklist, samples of draft title pages, and a section of helpful tips for the writers who use the department's desktop publishing software program, Adobe{reg_sign} FrameMaker{reg_sign}.
Date: December 1, 2002
Creator: ALLEN, TARA S.
Object Type: Report
System: The UNT Digital Library
Interim Measures to Limit the Migration of Radioactive Contaminants through the Vadose Zone at Hanford Single Shell Tank (SST) Farms (open access)

Interim Measures to Limit the Migration of Radioactive Contaminants through the Vadose Zone at Hanford Single Shell Tank (SST) Farms

None
Date: December 1, 2000
Creator: ANDERSON, F.J.
Object Type: Article
System: The UNT Digital Library
Rapid Ultrasensitive Chemical-Fingerprint Detection of Chemical and Biochemical Warfare Agents (open access)

Rapid Ultrasensitive Chemical-Fingerprint Detection of Chemical and Biochemical Warfare Agents

Vibrational spectra can serve as chemical fingerprints for positive identification of chemical and biological warfare molecules. The required speed and sensitivity might be achieved with surface-enhanced Raman spectroscopy (SERS) using nanotextured metal surfaces. Systematic and reproducible methods for preparing metallic surfaces that maximize sensitivity have not been previously developed. This work sought to develop methods for forming high-efficiency metallic nanostructures that can be integrated with either gas or liquid-phase chem-lab-on-a-chip separation columns to provide a highly sensitive, highly selective microanalytical system for detecting current and future chem/bio agents. In addition, improved protein microchromatographic systems have been made by the creation of acrylate-based porous polymer monoliths that can serve as protein preconcentrators to reduce the optical system sensitivity required to detect and identify a particular protein, such as a bacterial toxin.
Date: December 1, 2002
Creator: ASHBY, CAROL I.; SHEPODD, TIMOTHY J.; YELTON, WILLIAM G. & MURON, DAVID J.
Object Type: Report
System: The UNT Digital Library
DISPERSION ANALYSIS OF RADIATION/THERMAL FRONTS WITH FULL RESOLVED SPECTRAL OPACITY VARIATION. (open access)

DISPERSION ANALYSIS OF RADIATION/THERMAL FRONTS WITH FULL RESOLVED SPECTRAL OPACITY VARIATION.

The radiation transport and linearized thermal energy equations have been analyzed to find the temporal dependence of the component modes in a radiation/thermal front. The fully resolved spectral variation of the opacity as a function of energy, as well as the exact time and angular dependence, is treated in this work. As we are able to study arbitrarily complicated opacity spectra, we stress the importance of the new results as a check on the effect of using opacity averages.
Date: December 1, 2000
Creator: AUER, L. & LOWRIE, R.
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF A THERMAL EQUILIBRIUM PREDICTION ALGORITHM (open access)

DEVELOPMENT OF A THERMAL EQUILIBRIUM PREDICTION ALGORITHM

None
Date: December 1, 2001
Creator: AVILES-RAMOS, C.
Object Type: Article
System: The UNT Digital Library
Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays (open access)

Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays

The authors measure the mean lifetime, {tau} = 2/({Lambda}{sub L} + {Lambda}{sub H}), and the decay-width difference, {Delta}{Lambda} = {Lambda}{sub L} - {Lambda}{sub H}, of the light and heavy mass eigenstates of the B{sub s}{sup 0} meson, B{sub sL}{sup 0} and B{sub sH}{sup 0}, in B{sub s}{sup 0} {yields} J/{psi}{phi} decays using 1.7 fb{sup -1} of data collected with the CDF II detector at the Fermilab Tevatron p{bar p} collider. Assuming CP conservation, a good approximation for the B{sub s}{sup 0} system in the standard model, they obtain {Delta}{Lambda} = 0.076{sub -0.063}{sup +0.059}(stat.) {+-} 0.006(syst.) ps{sup -1} and {tau} = 1.52 {+-} 0.04(stat.) {+-} 0.02(syst.) ps, the most precise measurements to date. The constraints on the weak phase and {Delta}{Lambda} are consistent with CP conservation.
Date: December 1, 2007
Creator: Aaltonen, : T.
Object Type: Article
System: The UNT Digital Library
Observation of the Decay B+-(c) ---> J/psi pi+- and Measurement of the B+-(c) Mass (open access)

Observation of the Decay B+-(c) ---> J/psi pi+- and Measurement of the B+-(c) Mass

The B{sub c}{sup {+-}} meson is observed through the decay B{sub c}{sup {+-}} {yields} J/{psi} {pi}{sup {+-}}, in data corresponding to an integrated luminosity of 2.4 fb{sup -1} recorded by the CDF II detector at the Fermilab Tevatron. A signal of 108 {+-} 15 candidates is observed, with a significance that exceeds 8{sigma}. The mass of the B{sub c}{sup {+-}} meson is measured to be 6275.6 {+-} 2.9(stat.) {+-} 2.5(syst.) MeV/c{sup 2}.
Date: December 1, 2007
Creator: Aaltonen, T.
Object Type: Article
System: The UNT Digital Library
Search for doubly charged Higgs bosons with lepton-flavour-violating decays involving tau leptons (open access)

Search for doubly charged Higgs bosons with lepton-flavour-violating decays involving tau leptons

The authors search for pair production of doubly charged Higgs particles (H{sup {+-}{+-}}) followed by decays into electron-tau (e{tau}) and muon-tau ({mu}{tau}) pairs using a data set corresponding to an integrated luminosity of 350 pb{sup -1} collected from {bar p}p collisions at {radical}s = 1.96 TeV by the CDF II experiment. They search separately for cases where three or four final-state leptons are detected, and then combine the results into limits for each exclusive flavor decay mode of the H{sup {+-}{+-}}. Assuming 100% branching ratios of the H{sup {+-}{+-}} to left-handed e{tau} ({mu}{tau}) pairs, they set an H{sup {+-}{+-}} lower mass limit of 114 (112) GeV/c{sup 2} at the 95% confidence level (C.L.).
Date: December 1, 2007
Creator: Aaltonen, T.
Object Type: Article
System: The UNT Digital Library
Measurement of the top-quark mass in all-hadronic decays in p anti-p collisions at CDF II (open access)

Measurement of the top-quark mass in all-hadronic decays in p anti-p collisions at CDF II

We present a measurement of the top-quark mass, M{sub tpo}, in the all-hadronic decay channel t{bar t} {yields} W{sup +}bW{sup -}{bar b} {yields} q{sub 1}{bar q}{sub 2}bq{sub 3}{bar q}{sub 4}{bar b}. The analysis is performed using 310 pb{sup -1} of {radical}s = 1.96 TeV p{bar p} collisions collected with the CDF II detector using a multi-jet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of M{sub top} = 177.1 {+-} 4.9(stat.) {+-} 4.7(syst.) GeV/c{sup 2}.
Date: December 1, 2006
Creator: Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G. et al.
Object Type: Article
System: The UNT Digital Library
Observation of Exclusive Dijet Production at the Fermilab Tevatron p-pbar Collider (open access)

Observation of Exclusive Dijet Production at the Fermilab Tevatron p-pbar Collider

The authors present the first observation and cross section measurement of exclusive dijet production in {bar p}p interactions, {bar p}p {yields} {bar p} + dijet + p. Using a data sample of 310 pb{sup -1} collected by the Run II Collider Detector at Fermilab at {radical}s = 1.96 TeV, exclusive cross sections for events with two jets of transverse energy E{sub T}{sup jet} {ge} 10 GeV have been measured as a function of minimum E{sub T}{sup jet}. The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of 200 pb{sup -1} of b-tagged jet events, where exclusive dijet production is expected to be suppressed by the J{sub z} = 0 total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the pp Large Hadron Collider at {radical}s = 14 TeV are discussed.
Date: December 1, 2007
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Gonzalez, B.Alvarez; Amerio, S. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of Cross Sections for b Jet Production in Events with a Z Boson in p-anti-p Collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of Cross Sections for b Jet Production in Events with a Z Boson in p-anti-p Collisions at s**(1/2) = 1.96-TeV

A measurement of the b jet production cross section is presented for events containing a Z boson produced in p{bar p} collisions at {radical}s = 1.96 TeV, using data corresponding to an integrated luminosity of 2 fb{sup -1} collected by the CDF II detector at the Tevatron. Z bosons are selected in the electron and muon decay modes. Jets are considered with transverse energy E{sub T} > 20 GeV and pseudorapidity |{eta}| < 1.5 and are identified as b jets using a secondary vertex algorithm. The ratio of the integrated Z+b jet cross section to the inclusive Z production cross section is measured to be 3.32 {+-} 0.53(stat:) {+-} 0.42(syst:) x 10{sup -3}. This ratio is also measured differentially in jet E{sub T}, jet {eta}, Z-boson transverse momentum, number of jets, and number of b jets. The predictions from leading order Monte Carlo generators and next-to-leading-order QCD calculations are found to be consistent with the measurements within experimental and theoretical uncertainties.
Date: December 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Lambda_b Lifetime in Lambda_b -> Lambda_c+ pi- Decays in p-pbar Collisions at sqrt(s) = 1.96 TeV (open access)

Measurement of the Lambda_b Lifetime in Lambda_b -> Lambda_c+ pi- Decays in p-pbar Collisions at sqrt(s) = 1.96 TeV

We report a measurement of the lifetime of the {Lambda}{sub b}{sup 0} baryon in decays to the {Lambda}{sub c}{sup +} {pi}{sup -} final state in a sample corresponding to 1.1 fb{sup -1} collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed {Lambda}{sub b}{sup 0} events we measure {tau}({Lambda}{sub b}{sup 0}) = 1.401 {+-} 0.046 (stat) {+-} 0.035 (syst) ps (corresponding to c{tau}({Lambda}{sub b}{sup 0}) = 420.1 {+-} 13.7 (stat) {+-} 10.6 (syst) {micro}m, where c is the speed of light). The ratio of this result and the world average B{sup 0} lifetime yields {tau}({Lambda}{sub b}{sup 0})/{tau}(B{sup 0}) = 0.918 {+-} 0.038 (stat and syst), in good agreement with recent theoretical predictions.
Date: December 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for Technicolor Particles Produced in Association with a W Boson at CDF (open access)

Search for Technicolor Particles Produced in Association with a W Boson at CDF

We present a search for the technicolor particles {rho}{sub T} and {pi}{sub T} in the process p{bar p} {yields} {rho}{sub T} {yields} W{pi}{sub T} at a center of mass energy of {radical}s = 1.96 TeV. The search uses a data sample corresponding to approximately 1.9 fb{sup -1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is W {yields} {ell}{nu} and {pi}{sub T} {yields} b{bar b}, b{bar c} or b{bar u} depending on the {pi}{sub T} charge. We select events with a single high-p{sub T} electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple b-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the {rho}{sub T}-{pi}{sub T} mass plane. As a result, a large fraction of the region m({rho}{sub T}) = 180-250 GeV/c{sup 2} and m({pi}{sub T}) = 95-145 GeV/c{sup 2} is excluded.
Date: December 1, 2009
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 Flavor-Tagged Determination of Bounds on Mixing-Induced CP Violation in B0(s) ---> J/psi phi Decays (open access)

First Flavor-Tagged Determination of Bounds on Mixing-Induced CP Violation in B0(s) ---> J/psi phi Decays

This Letter describes the first determination of bounds on the CP-violation parameter 2{beta}{sub s} using B{sub s}{sup 0} decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2,000 B{sub s}{sup 0} {yields} J/{psi}{phi} decays reconstructed in a 1.35 fb{sup -1} data sample collected with the CDFII detector using p{bar p} collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2{beta}{sub s} and the decay-width difference {Delta}{Lambda}. Assuming the standard model predictions of 2{beta}{sub s} and {Delta}{Lambda}, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.
Date: December 1, 2007
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Search for Pair Production of Supersymmetric Top Quarks in Dilepton Events from $p\bar{p}$ Collisions at $\sqrt{s}$ = 1.96 TeV (open access)

Search for Pair Production of Supersymmetric Top Quarks in Dilepton Events from $p\bar{p}$ Collisions at $\sqrt{s}$ = 1.96 TeV

We present the results of a search for pair production of the supersymmetric partner of the top quark (the stop quark {approx}{sub 1}) decaying to a b-quark and a chargino {tilde {chi}}{sub 1}{sup {+-}} with a subsequent {tilde {chi}}{sub 1}{sup {+-}} decay into a neutralino {tilde {chi}}{sub 1}{sup 0}, lepton {ell}, and neutrino {nu}. Using a data sample corresponding to 2.7 fb{sup -1} of integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV collected by the CDF II detector, we reconstruct the mass of candidate stop events and fit the observed mass spectrum to a combination of standard model processes and stop quark signal. We find no evidence for {tilde t}{sub 1}{bar {tilde t}}{sub 1} production and set 95% C.L. limits on the masses of the stop quark and the neutralino for several values of the chargino mass and the branching ratio {Beta}({tilde {chi}}{sub 1}{sup {+-}} {yields} {tilde {chi}}{sub 1}{sup 0}{ell}{sup {+-}}{nu}).
Date: December 1, 2009
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method (open access)

Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method

The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.
Date: December 1, 2008
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the $W^+W^-$ Production Cross Section and Search for Anomalous $WW\gamma$ and $WWZ$ Couplings in $p \bar p$ Collisions at $\sqrt{s} = 1.96$ TeV (open access)

Measurement of the $W^+W^-$ Production Cross Section and Search for Anomalous $WW\gamma$ and $WWZ$ Couplings in $p \bar p$ Collisions at $\sqrt{s} = 1.96$ TeV

This Letter describes the current most precise measurement of the W boson pair production cross section and most sensitive test of anomalous WW{gamma} and WWZ couplings in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. The WW candidates are reconstructed from decays containing two charged leptons and two neutrinos, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector from 3.6 fb{sup -1} of integrated luminosity, a total of 654 candidate events are observed with an expected background contribution of 320 {+-} 47 events. The measured total cross section is {sigma}(p{bar p} {yields} W{sup +}W{sup -} + X) = 12.1 {+-} 0.9 (stat){sub -1.4}{sup +1.6} (syst) pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WW{gamma} and WWZ couplings.
Date: December 1, 2009
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 Fermion-Pair Decays $Q\Qbar \to (\t\Wmp)(\tbar\Wpm)$ in Same-Charge Dilepton Events (open access)

Search for Fermion-Pair Decays $Q\Qbar \to (\t\Wmp)(\tbar\Wpm)$ in Same-Charge Dilepton Events

We report the most restrictive direct limits on masses of fourth-generation down-type quarks b{prime}, and quark-like composite fermions (B or T{sub 5/3}), decaying promptly to tW{sup {-+}}. We search for a significant excess of events with two same-charge leptons (e, {mu}), several hadronic jets, and missing transverse energy. An analysis of data from p{bar p} collisions with an integrated luminosity of 2.7 fb{sup -1} collected with the CDF II detector at Fermilab yields no evidence for such a signal, setting mass limits m{sub b{prime}}, m{sub B} > 338 GeV/c{sup 2} and m{sub T{sub 5/3}} > 365 GeV/c{sup 2} at 95% confidence level.
Date: December 1, 2009
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 New Physics with a Dijet plus Missing Transverse Energy Signature in p-pbar Collisions at sqrt(s) = 1.96 TeV (open access)

Search for New Physics with a Dijet plus Missing Transverse Energy Signature in p-pbar Collisions at sqrt(s) = 1.96 TeV

We present results of a signature-based search for new physics using a dijet plus missing transverse energy (E{sub T}) data sample collected in 2 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a non-standard model process. Based on this limit the mass of a potential first or second generation scalar leptoquark is constrained to be above 187 GeV/c{sup 2}.
Date: December 1, 2009
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
Double parton interactions in photon+3 jet events in ppbar collisions sqrt{s}=1.96 TeV (open access)

Double parton interactions in photon+3 jet events in ppbar collisions sqrt{s}=1.96 TeV

We have used a sample of photon+3 jets events collected by the D0 experiment with an integrated luminosity of about 1 fb{sup -1} to determine the fraction of events with double parton scattering (f{sub DP}) in a single ppbar collision at {radical}s = 1.96 TeV. The DP fraction and effective cross section (sigma{sub eff}), a process-independent scale parameter related to the parton density inside the nucleon, are measured in three intervals of the second (ordered in p{sub T}) jet transverse momentum pT{sub jet2} within the range 15 < pT{sub jet2} < 30 GeV. In this range, f{sub DP} varies between 0.23 < f{sub DP} < 0.47, while sigma{sub eff} has the average value sigma{sub effave} = 16.4 {+-} 0.3(stat) {+-} 2.3(syst) mb.
Date: December 1, 2009
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Evidence for production of single top quarks and first direct measurement of |Vtb| (open access)

Evidence for production of single top quarks and first direct measurement of |Vtb|

The D0 Collaboration presents first evidence for the production of single top quarks at the Fermilab Tevatron p{bar p} collider. Using a 0.9 fb{sup -1} dataset, we apply a multivariate analysis to separate signal from background and measure {sigma}(p{bar p} {yields} tb + X, tqb + X) = 4.9 {+-} 1.4 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.035%, corresponding to a 3.4 standard deviation significance. We use the cross section measurement to directly determine the CKM matrix element that describes the W tb coupling and find 0.68 < |V{sub tb}| {le} 1 at 95% C.L.
Date: December 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
First measurement of sigma (p anti-p ---> Z) . Br (Z ---> tau tau) at s**(1/2) = 1.96- TeV (open access)

First measurement of sigma (p anti-p ---> Z) . Br (Z ---> tau tau) at s**(1/2) = 1.96- TeV

The authors present a measurement of the cross section for Z production times the branching fraction to {tau} leptons, {sigma} {center_dot} Br(Z {yields} {tau}{sup +}{tau}{sup -}), in p{bar p} collisions at {radical}s = 1.96 TeV in the channel in which one {tau} decays into {mu}{nu}{sub {mu}}{nu}{sub {tau}}, and the other into hadrons + {nu}{sub {tau}} or e{nu}{sub e}{nu}{sub {tau}}. The data sample corresponds to an integrated luminosity of 226 pb{sup -1} collected with the D0 detector at the Fermilab Tevatron collider. The final sample contains 2008 candidate events with an estimated background of 55%. From this they obtain {sigma} {center_dot} Br(Z {yields} {tau}{sup +}{tau}{sup -}) = 237 {+-} 15(stat) {+-} 18(sys) {+-} 15(lum) pb, in agreement with the standard model prediction.
Date: December 1, 2004
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the B0(s) semileptonic branching ratio to an orbitally excited D**(s) state, Br(B0(s) ---> D-(s1)(2536) mu+ nu X) (open access)

Measurement of the B0(s) semileptonic branching ratio to an orbitally excited D**(s) state, Br(B0(s) ---> D-(s1)(2536) mu+ nu X)

In a data sample of approximately 1.3 fb{sup -1} collected with the D0 detector between 2002 and 2006, the orbitally excited charm state D{sub s1}{sup {+-}}(2536) has been observed with a measured mass of 2535.7 {+-} 0.6(stat) {+-} 0.5(syst) MeV/c{sup 2} via the decay mode B{sub s}{sup 0} {yields} D{sub s1}{sup -}(2536){mu}{sup +} {nu}X. A first measurement is made of the branching ratio product Br({bar B} {yields} D{sub s1}{sup -}(2536){mu}{sup +}{nu}X) {center_dot} Br(D{sub s1}{sup -} {yields} D*{sup -} K{sub S}{sup 0}). Assuming that D{sub s1}{sup -}(2536) production in semileptonic decay is entirely from B{sub s}{sup 0}, an extraction of the semileptonic branching ratio Br(B{sub s}{sup 0} {yields} D{sub s1}{sup -}(2536){mu}{sup +}{nu}X) is made.
Date: December 1, 2007
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the p anti-p --> t anti-t production cross section at s**(1/2) = 1.96-TeV in the fully hadronic decay channel. (open access)

Measurement of the p anti-p --> t anti-t production cross section at s**(1/2) = 1.96-TeV in the fully hadronic decay channel.

A measurement of the top quark pair production cross section in proton anti-proton collisions at an interaction energy of {radical}s = 1.96 TeV is presented. This analysis uses 405 pb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic t{bar t} decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The t{bar t} cross section is measured as {sigma}{sub t{bar t}} = 4.5{sub -1.9}{sup +2.0}(stat){sub -1.1}{sup +1.4}(syst) {+-} 0.3(lumi) pb for a top quark mass of m{sub t} = 175 GeV/c{sup 2}.
Date: December 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library