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Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96 = TeV using kinematic characteristics of lepton + jets events (open access)

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96 = TeV using kinematic characteristics of lepton + jets events

We present a measurement of the top quark pair (t{bar t}) production cross section ({sigma}{sub t{bar t}}) in p{bar p} collisions at a center-of-mass energy of 1.96 TeV using 230 pb{sub -1} of data collected by the D0 detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the t{bar t} content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure {sigma}{sub t{bar t}} = 6.7{sub -1.3}{sup +1.4}(stat){sub -1.1}{sup +1.6}(syst) {+-} 0.4(lumi)pb, in good agreement with the standard model prediction.
Date: April 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 t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV using lepton + jets events with lifetime b-tagging (open access)

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV using lepton + jets events with lifetime b-tagging

We present a measurement of the top quark pair (t{bar t}) production cross section ({sigma}{sub t{bar t}}) 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. We select events with one charged lepton (electron or muon), missing transverse energy, and jets in the final state. We employ lifetime-based b-jet identification techniques to further enhance the t{bar t} purity of the selected sample. For a top quark mass of 175 GeV, we measure {sigma}{sub t{bar t}} = 8.6{sub -1.5}{sup +1.6}(stat. + syst.) {+-} 0.6 (lumi.) pb, in agreement with the standard model expectation.
Date: April 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
Multivariate searches for single top quark production with the D0 detector (open access)

Multivariate searches for single top quark production with the D0 detector

We present a search for electroweak production of single top quarks in (p{bar p} {yields} t{bar b} + X) and t-channel (p{bar p} {yields} tq{bar b} + X) modes. We have analyzed 230 pb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider at a center-of-mass energy of {radical}s = 1.96 TeV. Two separate analysis methods are used: neural networks and a cut-based analysis. No evidence for a single top quark signal is found. We set 95% confidence level upper limits on the production cross sections using Bayesian statistics, based on event counts and binned likelihoods formed from the neural network output. The limits from the neural network (cut-based) analysis are 6.4 pb (10.6 pb) in the s-channel and 5.0 pb (11.3 pb) in the t-channel.
Date: April 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
A Precise measurement of the B0(s) lifetime (open access)

A Precise measurement of the B0(s) lifetime

The authors report a measurement of the B{sub s}{sup 0} lifetime in the semileptonic decay channel B{sub s}{sup 0} {yields} D{sub s}{sup -}{mu}{sup +}{nu}X (and its charge conjugate), using approximately 0.4 fb{sup -1} of data collected with the D0 detector during 2002-2004. They have reconstructed 5176 D{sub s}{sup -} {mu}{sup +} signal events, where the D{sub s}{sup -} is identified via the decay D{sub s}{sup 0} {yields} {phi}{pi}{sup -}, followed by {phi} {yields} K{sup +}K{sup -}. Using these events, they have measured the B{sub s}{sup 0} lifetime to be {tau}(B{sub s}{sup 0}) = 1.398 {+-} 0.044 (stat){sub -0.025}{sup +0.028}(syst) ps. This is the most precise measurement of the B{sub s}{sup 0} lifetime to date.
Date: April 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
Production of WZ events in p anti-p collisions at s**(1/2) = 1.96-TeV and limits on anomalous WWZ couplings (open access)

Production of WZ events in p anti-p collisions at s**(1/2) = 1.96-TeV and limits on anomalous WWZ couplings

The authors present results from a search for WZ production with subsequent decay to {ell}{nu}{ell}'{bar {ell}}' ({ell} and {ell}' = e or {mu}) using 0.30 fb{sup -1} of data collected by the D0 experiment between 2002 and 2004 at the Tevatron. Three events with WZ decay characteristics are observed. With an estimated background of 0.71 {+-} 0.08 events, we measure the WZ production cross section to be 4.5{sub -2.6}{sup +3.8} pb, with a 95% C.L. upper limit of 13.3 pb. The 95% C.L. limits for anomalous WWZ couplings are found to be -2.0 < {Delta}{kappa}{sub Z} < 2.4 for form factor scale {Lambda} = 1 TeV, and -0.48 < {lambda}{sub Z} < 0.48 and -0.49 < {Delta}g{sub 1}{sup Z} < 0.66 for {Lambda} = 1.5 TeV.
Date: April 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
Search for a Higgs boson produced in association with a Z boson in p anti-p collisions (open access)

Search for a Higgs boson produced in association with a Z boson in p anti-p collisions

We describe a search for the standard model Higgs boson with a mass of 105 GeV/c{sup 2} to 145 GeV/c{sup 2} in data corresponding to an integrated luminosity of approximately 450 pb{sup -1} collected with the D0 detector at the Fermilab Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV. The Higgs boson is required to be produced in association with a Z boson, and the Z boson is required to decay to either electrons or muons with the Higgs boson decaying to a b{bar b} pair. The data are well described by the expected background, leading to 95% confidence level cross section upper limits {sigma}p{bar p} {yields} ZH x B(H {yields} b{bar b}) in the range of 3.1 pb to 4.4 pb.
Date: April 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
Search for excited muons in p anti-p collisions at s**(1/2) = 1.96- TeV (open access)

Search for excited muons in p anti-p collisions at s**(1/2) = 1.96- TeV

We present the results of a search for the production of an excited state of the muon, {mu}*, in proton antiproton collisions at {radical}s = 1.96 TeV. The data have been collected with the D0 experiment at the Fermilab Tevatron Collider and correspond to an integrated luminosity of approximately 380 pb{sup -1}. We search for {mu}* in the process p{bar p} {yields} {mu}*{nu}, with the {mu}* subsequently decaying to a muon plus photon. No excess above the standard model expectation is observed in data. Interpreting our data in the context of a model that describes {mu}* production by four-fermion contact interactions and {mu}* decay via electroweak processes, we exclude production cross sections higher than 0.057 pb-0.112 pb at the 95% confidence level, depending on the mass of the excited muon. Choosing the scale for contact interactions to be {Lambda} = 1 TeV, excited muon masses below 618 GeV are excluded.
Date: April 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
Search for neutral supersymmetric Higgs bosons in multijet events at s**(1/2) = 1.96-TeV (open access)

Search for neutral supersymmetric Higgs bosons in multijet events at s**(1/2) = 1.96-TeV

We have performed a search for neutral Higgs bosons produced in association with bottom quarks in p{bar p} collisions, using 260 pb{sup -1} of data collected with the D0 detector in Run II of the Fermilab Tevatron Collider. The cross sections for these processes are enhanced in many extensions of the standard model (SM), such as in its minimal supersymmetric extension at large tan {beta}. The results of our analysis agree with expectations from the SM, and we use our measurements to set upper limits on the production of neutral Higgs bosons in the mass range of 90 to 150 GeV.
Date: April 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
Search for supersymmetry via associated production of charginos and neutralinos in final states with three leptons (open access)

Search for supersymmetry via associated production of charginos and neutralinos in final states with three leptons

None
Date: April 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
The Low-Income Home Energy Assistance Program: How are State Allotments Determined? (open access)

The Low-Income Home Energy Assistance Program: How are State Allotments Determined?

This report discusses the Low-Income Home Energy Assistance Program (LIHEAP), which is a block grant program under which the federal government provides states annual grants to operate multi-component home energy assistance programs for needy households.
Date: April 17, 2001
Creator: Abbey, Craig W.
Object Type: Report
System: The UNT Digital Library
Radiological Dose Calculations for Fusion Facilities (open access)

Radiological Dose Calculations for Fusion Facilities

This report summarizes the results and rationale for radiological dose calculations for the maximally exposed individual during fusion accident conditions. Early doses per unit activity (Sieverts per TeraBecquerel) are given for 535 magnetic fusion isotopes of interest for several release scenarios. These data can be used for accident assessment calculations to determine if the accident consequences exceed Nuclear Regulatory Commission and Department of Energy evaluation guides. A generalized yearly dose estimate for routine releases, based on 1 Terabecquerel unit releases per radionuclide, has also been performed using averaged site parameters and assumed populations. These routine release data are useful for assessing designs against US Environmental Protection Agency yearly release limits.
Date: April 1, 2003
Creator: Abbott, Michael L.; Cadwallader, Lee C. & Petti, David A.
Object Type: Report
System: The UNT Digital Library
Anode Sheath Switching in a Carbon Nanotube Arc Plasma (open access)

Anode Sheath Switching in a Carbon Nanotube Arc Plasma

The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.
Date: April 8, 2008
Creator: Abe Fetterman, Yevgeny Raitses, and Michael Keidar
Object Type: Report
System: The UNT Digital Library
Electric Transmission: Approaches for Energizing a Sagging Industry (open access)

Electric Transmission: Approaches for Energizing a Sagging Industry

This report discusses factors that have contributed to the lack of new transmission capacity and some of the resulting issues. This report reviews approaches being taken to address the lack of investment in transmission infrastructure and transmission congestion.
Date: April 27, 2007
Creator: Abel, Amy
Object Type: Report
System: The UNT Digital Library
Electric Utility Regulatory Reform: Issues for the 109th Congress (open access)

Electric Utility Regulatory Reform: Issues for the 109th Congress

This report discusses regulation issues affecting electricity today. Comprehensive electricity legislation may involve several components: Public Utility Holding Company Act (PUHCA) reform, PURPA's requirement that utilities purchase power from qualifying facilities (QFs), and reliability.
Date: April 21, 2005
Creator: Abel, Amy
Object Type: Report
System: The UNT Digital Library
Electricity: The Road Toward Restructuring (open access)

Electricity: The Road Toward Restructuring

The Public Utility Holding Company Act of 1935 (PUHCA) and the Federal Power Act (FPA) were enacted to eliminate unfair practices and other abuses by electricity and gas holding companies by requiring federal control and regulation of interstate public utility holding companies. Comprehensive energy legislation has passed the House and Senate. The House passed H.R. 6 on April 11, 2003. On July 31, 2003, the Senate suspended debate on S. 14, inserted the text of H.R. 4 (107th Congress) as a substitute, and passed H.R. 6. A conference agreement was reached November 17, 2003, and passed by the House the next day. H.R. 6 includes an electricity title that would, in part, repeal PUHCA, would prospectively repeal the mandatory purchase requirement under PURPA, and would create an electric reliability organization. On June 15, 2004, H.R. 4503, a comprehensive energy policy bill, passed the House.
Date: April 8, 2003
Creator: Abel, Amy & Parker, Larry
Object Type: Report
System: The UNT Digital Library
Electric Utility Infrastructure Vulnerabilities: Transformers, Towers, and Terrorism (open access)

Electric Utility Infrastructure Vulnerabilities: Transformers, Towers, and Terrorism

None
Date: April 9, 2004
Creator: Abel, Amy; Parfomak, Paul W. & Shea, Dana A.
Object Type: Report
System: The UNT Digital Library
Ideas and concepts for diagnosis of performance and evaluation of data reliability based upon ARSA state-of-health (SOH) data (open access)

Ideas and concepts for diagnosis of performance and evaluation of data reliability based upon ARSA state-of-health (SOH) data

At the current time, the Pacific Northwest National Laboratory (PNNL) prototype for the Automated Radioxenon Sampler/Analyzer (ARSA) automatically transmits, on a daily basis, a subset of all state-of-health (SOH) data in an e-mail data file to a limited number of recipients. These variables represent what were considered the most critical physical parameters for the ARSA's operation at the beginning of the field demonstration in Freiburg, Germany. Operators at PNNL perform a daily review of the information in the data file for anomalous operational conditions as evidenced by sensor readings. The initial review is easily implemented by plotting the various sensor data versus time and looking for gross deviations in the periodicity of the variables compared to previous sample sensor data. After viewing the 24-hr graphical plots, if necessary, a review is conducted of the tabular data of specific sensor anomalies. In most cases, the experience has been that when there is an ARSA operational problem the data file will have multiple sensor readings that reflect some aspect of the problem.
Date: April 27, 2000
Creator: Abel, KH; Bowyer, TW; Hayes, JC; Heimbigner, TR; Panisko, ME; McIntyre, JI et al.
Object Type: Report
System: The UNT Digital Library
Ideas and Concepts for Diagnosis of Performance and Evaluation of Data Reliability Based Upon ARSA State-of-Health (SOH) Data (open access)

Ideas and Concepts for Diagnosis of Performance and Evaluation of Data Reliability Based Upon ARSA State-of-Health (SOH) Data

At the current time the Pacific Northwest National Laboratory (PNNL) prototype for the Automated Radioxenon Sampler/Analyzer (ARSA) automatically transmits, on a daily basis, a subset of all state-of-health (SOH) data in an e-mail data file to a limited distribution of participants.
Date: April 27, 2000
Creator: Abel, Keith H.; Bowyer, Ted W.; Hayes, James C.; Heimbigner, Tom R.; Panisko, Mark E.; McIntyre, Justin I. et al.
Object Type: Report
System: The UNT Digital Library
Abilene Philharmonic Playbill: April 6-May 4, 2002 (open access)

Abilene Philharmonic Playbill: April 6-May 4, 2002

Program for an Abilene Philharmonic concert that ran from April 6th to May 4th during the 51st season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date: April 2002
Creator: Abilene Philharmonic
Object Type: Book
System: The Portal to Texas History
Abilene Philharmonic Playbill: April 2-May 7, 2005 (open access)

Abilene Philharmonic Playbill: April 2-May 7, 2005

Program for an Abilene Philharmonic concert that ran from April 2nd to May 7th during the 55th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date: April 2005
Creator: Abilene Philharmonic
Object Type: Pamphlet
System: The Portal to Texas History
Abilene Philharmonic Playbill: April 22, 2006 (open access)

Abilene Philharmonic Playbill: April 22, 2006

Program for an Abilene Philharmonic concert that ran on April 22nd (Pop III) during the 56th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date: April 2006
Creator: Abilene Philharmonic
Object Type: Pamphlet
System: The Portal to Texas History
Measurement of direct photon emission in the K(L) ---> pi+ pi- gamma decay mode (open access)

Measurement of direct photon emission in the K(L) ---> pi+ pi- gamma decay mode

In this paper the KTeV collaboration reports the analysis of 112.1 x 10{sup 3} candidate K{sub L} {yields} {pi}{sup +}{pi}{sup -}{gamma} decays including a background of 671 {+-} 41 events with the objective of determining the photon production mechanisms intrinsic to the decay process. These decays have been analyzed to extract the relative contributions of the Cp violating bremsstrahlung process and the CP conserving M1 and CP violating E1 direct photon emission processes. The M1 direct photon emission amplitude and its associated vector form factor parameterized as |{bar g}{sub M1}|(1 + a{sub 1}/a{sub 2}/(M{sub {rho}}{sup 2}-M{sub K}{sup 2}) + 2M{sub K}E{sub {gamma}}) have been measured to be |{bar g}{sub M1}| = 1.198 {+-} 0.035(stat) {+-} 0.086(syst) and a{sub 1}/a{sub 2} = =0.738 {+-} 0.007(stat) {+-} 0.018(syst) GeV{sup 2}/c{sup 2} respectively. An upper limit for the CP violating E1 direct emission amplitude |g{sub E1}| {le} 0.1 (90%CL) has been found. The overall ratio of direct photon emission (DE) to total photon emission including the bremsstrahlung process (IB) has been determined to be DE/(DE + IB) = 0.689 {+-} 0.021 for E{sub {gamma}} {ge} 20 MeV.
Date: April 1, 2006
Creator: Abouzaid, E.; Arenton, M.; Barker, A. R.; Bellantoni, L.; Bellavance, A.; Blucher, E. et al.
Object Type: Article
System: The UNT Digital Library
Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis (open access)

Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis

Article on air to blood distribution of volatile organic compounds and a linear free energy analysis.
Date: April 23, 2005
Creator: Abraham, M. H. (Michael H.); Ibrahim, Adam & Acree, William E. (William Eugene)
Object Type: Article
System: The UNT Digital Library
Air to Muscle and Blood/Plasma to Muscle Distribution of Volatile Organic Compounds and Drugs: Linear Free Energy Analyses (open access)

Air to Muscle and Blood/Plasma to Muscle Distribution of Volatile Organic Compounds and Drugs: Linear Free Energy Analyses

Article on air to muscle and blood/plasma to muscle distribution of volatile organic compounds and drugs and linear free energy analyses.
Date: April 20, 2006
Creator: Abraham, M. H. (Michael H.); Ibrahim, Adam & Acree, William E. (William Eugene)
Object Type: Article
System: The UNT Digital Library