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275,061 Matching Results

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Best Match Title Creator Date Created (Newest) Date Created (Oldest) Date Added (Newest) Date Added (Oldest)
Measurement of $d\sigma/dy$ of Drell-Yan $e^+e^-$ pairs in the $Z$ Mass Region from $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV (open access)

Measurement of $d\sigma/dy$ of Drell-Yan $e^+e^-$ pairs in the $Z$ Mass Region from $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

We report on a CDF measurement of the total cross section and rapidity distribution, d{sigma}/dy, for q{bar q} {yields} {gamma}{sup *}/Z {yields} e{sup +} e {sup -} events in the Z boson mass region (66 < M {sub ee} < 116 GeV/c {sub 2}) produced in p{bar p} collisions at {radical}s = 1.96 TeV with 2.1 fb{sup -1} of integrated luminosity. The measured cross section of 257 {+-} 16pb and d{sigma}/dy distribution are compared with Next-to-Leading-Order (NLO) and Next-to-Next-to-Leading-Order (NNLO) QCD theory predictions with CTEQ and MRST/MSTW parton distribution functions (PDFs). There is good agreement between the experimental total cross section and d{sigma}/dy measurements with theoretical calcualtion with the most recent NNLO PDFs.
Date: March 1, 2010
Creator: Aaltonen, Timo Antero; Phys., /Helsinki Inst. of; Adelman, Jahred A.; /Chicago U., EFI; Gonzalez, Barbara Alvarez; Phys., /Cantabria Inst. of et al.
Object Type: Article
System: The UNT Digital Library
Uranium Hydrogeochemical and Stream Sediment Pilot Study of the Boulder Batholith, Montana (open access)

Uranium Hydrogeochemical and Stream Sediment Pilot Study of the Boulder Batholith, Montana

This report presents the results of a uranium hydrogeochemical and stream sediment study made in the fall of 1976 of Boulder Batholith, Montana.
Date: March 1978
Creator: Aamodt, Paul L.
Object Type: Report
System: The UNT Digital Library
Uranium Hydrogeochemical and Stream Sediment Reconnaissance Data Release for the Montana Portion of the Hamilton, Montana/Idaho, NTMS Quadrangle (open access)

Uranium Hydrogeochemical and Stream Sediment Reconnaissance Data Release for the Montana Portion of the Hamilton, Montana/Idaho, NTMS Quadrangle

from Summary: This report describes work done in Hamilton, Montanan/Idaho, National Topographic Map Series (NTMS) quadrangle (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).
Date: March 1978
Creator: Aamodt, Paul L.
Object Type: Report
System: The UNT Digital Library
Prototype gauge for measuring contour and wall thicknesses of hemispherical parts. [Interferometer] (open access)

Prototype gauge for measuring contour and wall thicknesses of hemispherical parts. [Interferometer]

A prototype gauge (gage) was designed and fabricated using air bearings in a new configuration to provide less error and distortion during inspection of hemispherical parts. No wear occurs on the moving parts during operations and accuracy of alignment is maintained. The gauge will check outside radial distance, inside radial, and outside radial and wall, and inner radial and wall thicknesses of parts. The gauge contains only four moving parts, which increases the measuring accuracy. A horizontal table rotates. A table mounted on the horizontal table at 45/sup 0/ rotates through two transducers. All moving parts are mounted on hydrostatic gas bearings. Laser interferometric, air-bearing gauge heads are used to obtain the required data. Investigation of a hemispherical part is in any desired spiral path from equator to pole. Measurement information is obtained from two laser interferometric transducers using linear air bearings. The transducers use a Spectra Physics Model-120 helium and neon laser. Working range of each transducer is 1.5 inches. The fringe voltage signals are amplified and converted to inches to be displayed on a digital readout. A punched paper tape contains the nominal inside diameter (ID) and outside diameter (OD) information in Binary Coded Decimal form. The tape …
Date: March 1, 1976
Creator: Aarts, H. J. & Robertson, J. H.
Object Type: Report
System: The UNT Digital Library
Network load of X terminals at CDF (open access)

Network load of X terminals at CDF

As an aid to planning future usage of X terminals, the authors measured the network bandwidth used by X terminals on a single Ethernet in a typical application environment at Fermilab. The objectives were twofold. The first objective was to identify the impact of adding one more X terminal onto the CDF Ethernet . The second objective was to determine the maximum number of X terminals allowable on the CDF network. The findings reveal that an X terminal in this environment used, on average, 431 + /{minus}45 bytes/second. This is quite small compared to the utilizable bandwidth of the thinwire Ethernet network (375 Kilobytes/second, equivalent to 30% of total bandwidth). This amounts to an averaged load of .034% on the network per X terminal. This paper addresses the network load solely. It does not address the loads imposed by X terminals on the memory and CPU of the host systems.
Date: March 1, 1992
Creator: Abar, F.; O'Reilly, C. & Wicklund, E.
Object Type: Report
System: The UNT Digital Library
Network load of X terminals at CDF (open access)

Network load of X terminals at CDF

As an aid to planning future usage of X terminals, the authors measured the network bandwidth used by X terminals on a single Ethernet in a typical application environment at Fermilab. The objectives were twofold. The first objective was to identify the impact of adding one more X terminal onto the CDF Ethernet . The second objective was to determine the maximum number of X terminals allowable on the CDF network. The findings reveal that an X terminal in this environment used, on average, 431 + /{minus}45 bytes/second. This is quite small compared to the utilizable bandwidth of the thinwire Ethernet network (375 Kilobytes/second, equivalent to 30% of total bandwidth). This amounts to an averaged load of .034% on the network per X terminal. This paper addresses the network load solely. It does not address the loads imposed by X terminals on the memory and CPU of the host systems.
Date: March 1, 1992
Creator: Abar, F.; O`Reilly, C. & Wicklund, E.
Object Type: Report
System: The UNT Digital Library
Using field theory in hadron physics (open access)

Using field theory in hadron physics

Topics are covered on the connection of field theory and hadron physics. The renormalization group and infrared and ultraviolet limits of field theory, in particular quantum chromodynamics, spontaneous mass generation, color confinement, instantons, and the vacuum state in quantum chromodynamics are treated. 21 references. (JFP)
Date: March 1, 1978
Creator: Abarbanel, H.D.I.
Object Type: Article
System: The UNT Digital Library
Study of electron and neutrino interactions (open access)

Study of electron and neutrino interactions

This is the final report for the DOE-sponsored experimental particle physics program at Virginia Tech to study the properties of the Standard Model of strong and electroweak interactions. This contract (DE-AS05-80ER10713) covers the period from August 1, 1980 to January 31, 1993. Task B of this contract, headed by Professor Alexander Abashian, is described in this final report. This program has been pursued on many fronts by the researchers-in a search for axions at SLAC, in electron-positron collisions in the AMY experiment at the TRISTAN collider in Japan, in measurements of muon decay properties in the MEGA and RHO experiments at the LAMPF accelerator, in a detailed analysis of scattering effects in the purported observation of a 17 keV neutrino at Oxford, in a search for a disoriented chiral condensate with the MiniMax experiment at Fermilab, and in an R&D program on resistive plate counters that could find use in low-cost high-quality charged particle detection at low rates.
Date: March 18, 1997
Creator: Abashian, A.
Object Type: Report
System: The UNT Digital Library
Study of electron and neutrino interactions. Final report (open access)

Study of electron and neutrino interactions. Final report

This is the final report for the DOE-sponsored experimental particle physics program at Virginia Tech to study the properties of the Standard Model of strong and electroweak interactions. This contract (DE-AS05-80ER10713) covers the period from August 1, 1980 to January 31, 1993. Task B of this contract, headed by Professor Alexander Abashian, is described in this final report. This program has been pursued on many fronts by the researchers in a search for axions at SLAC, in electron-positron collisions in the AMY experiment at the TRISTAN collider in Japan, in measurements of muon decay properties in the MEGA and RHO experiments at the LAMPF accelerator, in a detailed analysis of scattering effects in the purported observation of a 17 keV neutrino at Oxford, in a search for a disoriented chiral condensate with the MiniMax experiment at Fermilab, and in an R&D program on resistive plate counters that could find use in low-cost high-quality charged particle detection at low rates.
Date: March 18, 1997
Creator: Abashian, A.
Object Type: Report
System: The UNT Digital Library
Evidence for production of single top quarks (open access)

Evidence for production of single top quarks

We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p{bar p} collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top quark partner that is always produced from strong coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top quark production has been searched for in ever larger datasets. In this analysis, we select events from a 0.9 fb{sup -1} dataset that have an electron or muon and missing transverse energy from the decay of a W boson from the top quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and t{bar t} events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross …
Date: March 1, 2008
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 direct two-sided bound on the B0(s) oscillation frequency (open access)

First direct two-sided bound on the B0(s) oscillation frequency

The authors report the first direct two-sided bound on the B{sub s}{sup 0} oscillation frequency using a large sample of B{sub s}{sup 0} semileptonic decays corresponding to approximately 1 fb{sup -1} of integrated luminosity collected by the D0 experiment in 2002-2006 during Run II of the Fermilab Tevatron Collider. The flavor (i.e., B{sub s}{sup 0} or B{sub s}{sup 0}) of the B{sub s}{sup 0} meson at the time of production was found using an opposite-side tagging technique, and the flavor at the time of decay was determined from the charge of the muon in the partially reconstructed decay B{sub s}{sup 0} {yields} {mu}{sup +} D{sub s}{sup -}X, D{sub s}{sup -} {yields} {phi}{pi}{sup -}, {phi} {yields} K{sup +}K{sup -}. A likelihood scan over the oscillation frequency, {Delta}m{sub s}, gives a most probable value of 19 ps{sup -1} and a range of 17 < {Delta}m{sub s} < 21 ps{sup -1} at the 90% C.L. At {Delta}m{sub s} = 19 ps{sup -1}, the amplitude method yields a result that deviates from the hypothesis of an oscillation amplitude of zero by 2.5 standard deviations, corresponding to a two-sided C.L. of 1%.
Date: March 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 study of the radiation-amplitude zero in W gamma production and limits on anomalous WW gamma couplings at s**(1/2) = 1.96- TeV (open access)

First study of the radiation-amplitude zero in W gamma production and limits on anomalous WW gamma couplings at s**(1/2) = 1.96- TeV

None
Date: March 1, 2008
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 B(t ---> Wb)/B(t ---> Wq) at s**(1/2) = 1.96-TeV (open access)

Measurement of B(t ---> Wb)/B(t ---> Wq) at s**(1/2) = 1.96-TeV

The authors present the measurement of R = {Beta}(t {yields} Wb)/{Beta}(t {yields} Wq) in p{bar p} collisions at {radical}s = 1.96 TeV, using 230 pb{sup -1} of data collected by the D0 experiment at the Fermilab Tevatron Collider. They fit simultaneously R and the number (N{sub t{bar t}}) of selected top quark pairs (t{bar t}), to the number of identified b-quark jets in events with one electron or one muon, three or more jets, and high transverse energy imbalance. To improve sensitivity, kinematical properties of events with no identified b-quark jets are included in the fit. They measure R = 1.03{sub -0.17}{sup +0.19}(stat+syst), in good agreement with the standard model. They set lower limits of R > 0.61 and |V{sub tb}| > 0.78 at 95% confidence level.
Date: March 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
Measurement of the p - anti-p ---> W gamma + X cross section at s**(1/2) = 1.96-TeV and WW gamma anomalous coupling limits (open access)

Measurement of the p - anti-p ---> W gamma + X cross section at s**(1/2) = 1.96-TeV and WW gamma anomalous coupling limits

The WW{gamma} triple gauge boson coupling parameters are studied using p{bar p} {yields} {ell}{nu}{gamma} + X({ell} = e, {mu}) events at {radical}s = 1.96 TeV. The data were collected with the D0 detector from an integrated luminosity of 162 pb{sup -1} delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p{bar p} {yields} W({gamma}) + X {yields} {ell}{nu}{gamma} + X with E{sub T}{sup {gamma}} > 8 GeV and {Delta}R{sub {ell}{gamma}} > 0.7 is 14.8 {+-} 1.6(stat) {+-} 1.0(syst) {+-} 1.0(lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < {Delta}{kappa}{sub {gamma}} < 0.96 and -0.20 < {lambda}{sub {gamma}} < 0.20.
Date: March 1, 2005
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 ratio of the p anti-p ---> W+c-jet cross section to the inclusive p anti-p ---> W+jets cross section (open access)

Measurement of the ratio of the p anti-p ---> W+c-jet cross section to the inclusive p anti-p ---> W+jets cross section

None
Date: March 1, 2008
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 t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV

We measure the t{bar t} production cross section in p{bar p} collisions at {radical}s = 1.96 TeV in the lepton+jets channel. Two complementary methods discriminate between signal and background, b-tagging and a kinematic likelihood discriminant. Based on 0.9 fb{sup -1} of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure {sigma}{sub t{bar t}} = 7.62 {+-} 0.85 pb, assuming the current world average m{sub t} = 172.6 GeV. We compare our cross section measurement with theory predictions to determine a value for the top quark mass of 170 {+-} 7 GeV.
Date: March 1, 2008
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
Search for h(f) ---> gamma gamma with the D0 detector at s**(1/2) = 1.96-TeV (open access)

Search for h(f) ---> gamma gamma with the D0 detector at s**(1/2) = 1.96-TeV

None
Date: March 1, 2008
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
Search for large extra dimensions in the mono-photon final state at s**(1/2) = 1.96-TeV (open access)

Search for large extra dimensions in the mono-photon final state at s**(1/2) = 1.96-TeV

The authors report on a search for large extra dimensions in a data sample of approximately 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV. They investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. they set limits on the fundamental mass scale M{sub D} from 884 GeV to 778 GeV for 2 to 8 extra dimensions.
Date: March 1, 2008
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
Search for scalar top quarks in the acoplanar charm jets and missing transverse energy final state in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for scalar top quarks in the acoplanar charm jets and missing transverse energy final state in p anti-p collisions at s**(1/2) = 1.96-TeV

None
Date: March 1, 2008
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
Search for W-prime Boson Resonances Decaying to a Top Quark and a Bottom Quark (open access)

Search for W-prime Boson Resonances Decaying to a Top Quark and a Bottom Quark

We search for the production of a heavy W{prime} gauge boson that decays to third generation quarks in 0.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron collider. We find no significant excess in the final-state invariant mass distribution and set upper limits on the production cross section times branching fraction. For a left-handed W{prime} boson with SM couplings, we set a lower mass limit of 731 GeV. For right-handed W{prime} bosons, we set lower mass limits of 739 GeV if the W{prime} boson decays to both leptons and quarks and 768 GeV if the W{prime} boson decays only to quarks. We also set limits on the coupling of the W{prime} boson to fermions as a function of its mass.
Date: March 1, 2008
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
Measurements of differential cross sections of Z/gamma*+jets+X events in proton anti-proton collisions at s**(1/2) = 1.96-TeV (open access)

Measurements of differential cross sections of Z/gamma*+jets+X events in proton anti-proton collisions at s**(1/2) = 1.96-TeV

We present cross section measurements for Z/{gamma}* + jets + X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the D0 detector at the Fermilab Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb{sup -1}. Leading and next-to-leading order perturbative QCD predictions are compared with the measurements, and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the shapes observed in data, but the predicted normalizations show significant differences with respect to the data, reflecting large scale uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.
Date: March 1, 2009
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, Bannanje Sripath; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Observation of Single Top Quark Production (open access)

Observation of Single Top Quark Production

We report first observation of the electroweak production of single top quarks in p{bar p} collisions at {radical}s = 1.96 TeV based on 2.3 fb{sup ?1} of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.94 {+-} 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10{sup ?7}, corresponding to a 5.0 standard deviation significance for the observation.
Date: March 1, 2009
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, Bannanje Sripath; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
The Muon system of the run II D0 detector (open access)

The Muon system of the run II D0 detector

The authors describe the design, construction and performance of the upgraded D0 muon system for Run II of the Fermilab Tevatron collider. Significant improvements have been made to the major subsystems of the D0 muon detector: trigger scintillation counters, tracking detectors, and electronics. The Run II central muon detector has a new scintillation counter system inside the iron toroid and an improved scintillation counter system outside the iron toroid. In the forward region, new scintillation counter and tracking systems have been installed. Extensive shielding has been added in the forward region. A large fraction of the muon system electronics is also new.
Date: March 1, 2005
Creator: Abazov, V. M.; Acharya, B. S.; Alexeev, G. D.; Alkhazov, G.; Anosov, V. A.; Baldin, B. et al.
Object Type: Article
System: The UNT Digital Library
Observation of a narrow mass state decaying into $\Upsilon(1S) + \gamma$ in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV (open access)

Observation of a narrow mass state decaying into $\Upsilon(1S) + \gamma$ in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV

Using data corresponding to an integrated luminosity of 1.3 fb{sup -1}, we observe a narrow mass state decaying into {Upsilon}(1S) + {gamma}, where the {Upsilon}(1S) meson is detected by its decay into a pair of oppositely charged muons, and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard deviations. The mass of the state is centered at 10.551 {+-} 0.014(stat.) {+-} 0.017(syst.) GeV/c{sup 2}, which is consistent with that of the state recently observed by the ATLAS Collaboration.
Date: March 1, 2012
Creator: Abazov, Victor Mukhamedovich & al., et
Object Type: Article
System: The UNT Digital Library