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Search for neutral Higgs bosons decaying to tau pairs in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for neutral Higgs bosons decaying to tau pairs in p anti-p collisions at s**(1/2) = 1.96-TeV

A search for the production of neutral Higgs bosons {Phi} decaying into {tau}{sup +}{tau}{sup -} final states in p{bar p} collisions at a center-of-mass energy of 1.96 TeV is presented. The data, corresponding to an integrated luminosity of approximately 325 pb{sup -1}, were collected by the D0 experiment at the Fermilab Tevatron Collider. Since no excess compared to the expectation from standard model processes is found, limits on the production cross section times branching ratio are set. The results are combined with those obtained from the D0 search for {Phi}b({bar b}) {yields} b{bar b}b({bar b}) and are interpreted in the minimal supersymmetric standard model.
Date: May 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 particles decaying into a Z boson and a photon in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for particles decaying into a Z boson and a photon in p anti-p collisions at s**(1/2) = 1.96-TeV

The authors present the results of the first search for a new particle X produced in p{bar p} collisions at {radical}s = 1.96 TeV and subsequently decaying to Z{gamma}. The search uses 0.3 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron Collider. They set limits on the production cross section times the branching fraction {sigma}(p{bar p} {yields} X) x B(X {yields} Z{gamma}) that range from 0.4-3.5 pb at the 95% C.L. for X with invariant masses between 100 and 1000 GeV/c{sup 2} over a wide range of X decay widths.
Date: May 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 R-parity violating supersymmetry via the LL anti-E couplings lambda(121), lambda(122) or lambda(133) in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for R-parity violating supersymmetry via the LL anti-E couplings lambda(121), lambda(122) or lambda(133) in p anti-p collisions at s**(1/2) = 1.96-TeV

A search for gaugino pair production with a trilepton signature in the framework of R-parity violating supersymmetry via the couplings {lambda}{sub 121}, {lambda}{sub 122}, or {lambda}{sub 133} is presented. The data, corresponding to an integrated luminosity of L {approx} 360 pb{sup -1}, were collected from April 2002 to August 2004 with the D0 detector at the Fermilab Tevatron Collider, at a center-of-mass energy of {radical}s = 1.96 TeV. This analysis considers final states with three charged leptons with the flavor combinations ee{ell}, {mu}{mu}{ell}, and ee{tau} ({ell} = e or {mu}). No evidence for supersymmetry is found and limits at the 95% confidence level are set on the gaugino pair production cross section and lower bounds on the masses of the lightest neutralino and chargino are derived in two supersymmetric models.
Date: May 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 resonant second generation slepton production at the Tevatron (open access)

Search for resonant second generation slepton production at the Tevatron

The authors present a search for supersymmetry in the R-parity violating resonant production and decay of smuons and muon-sneutrinos in the channels {tilde {mu}} {yields} {tilde {chi}}{sub 1}{sup 0} {mu}, {tilde {mu}} {yields} {tilde {chi}}{sub 2,3,4}{sup 0} {mu}, and {tilde {nu}}{sub {mu}} {yields} {tilde {chi}}{sub 1,2}{sup {+-}} {mu}. They analyzed 0.38 fb{sup -1} of integrated luminosity collected between April 2002 and August 2004 with the D0 detector at the Fermilab Tevatron Collider. The observed number of events is in agreement with the standard model expectation, and we calculate 95% C.L. limits on the slepton production cross section times branching fraction to gaugino plus muon, as a function of slepton and gaugino masses. In the framework of minimal supergravity, we set limits on the coupling parameter {lambda}'{sub 211}, extending significantly previous results obtained in Run I of the Tevatron and at the CERN LEP collider.
Date: May 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 b jet cross-section in events with a Z boson in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of the b jet cross-section in events with a Z boson in p anti-p collisions at s**(1/2) = 1.96-TeV

None
Date: May 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M. G. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the ratio of branching fractions B(D0 ---> K+ pi-) / B(D0 ---> K- pi+) using the CDF II Detector (open access)

Measurement of the ratio of branching fractions B(D0 ---> K+ pi-) / B(D0 ---> K- pi+) using the CDF II Detector

The authors present a measurement of R{sub B}, the ratio of the branching fraction for the rare decay D{sup 0} {yields} K{sup +}{pi}{sup -} to that for the Cabibbo-favored decay D{sup 0} {yields} K{sup -}{pi}{sup +}. Charge conjugate decays are implicitly included. A signal of 2005 {+-} 104 events for the decay D{sup 0} {yields} K{sup +}{pi}{sup -} is obtained using the CDF II detector at the Fermilab Tevatron collider. The data set corresponds to an integrated luminosity of 0.35 fb{sup -1} produced in {bar p}p collisions at {radical}s = 1.96 TeV. Assuming no mixing, they find R{sub B} = [4.05 {+-} 0.21(stat) {+-} 0.11(syst)] x 10{sup -3}. This measurement is consistent with the world average, and comparable in accuracy with the best measurements from other experiments.
Date: May 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Search for a neutral Higgs boson decaying to a W boson pair in p antip collisions at s**(1/2) = 1.96-TeV (open access)

Search for a neutral Higgs boson decaying to a W boson pair in p antip collisions at s**(1/2) = 1.96-TeV

The authors present the results of a search for standard model Higgs boson production with decay to WW*, identified through the leptonic final states e{sup +}e{sup -} {bar {nu}}{nu}, e{sup {+-}}{mu}{sup {-+}} {bar {nu}}{nu} and {mu}{sup +} {mu}{sup -} {bar {nu}}{nu}. This search uses 360 pb{sup -1} of data collected from p{bar p} collisions at {radical}s = 1.96 TeV by the upgraded Collider Detector at Fermilab (CDF II). They observe no signal excess and set 95% confidence level upper limits on the production cross section times branching ratio for the Higgs boson to WW* or any new scalar particle with similar decay products. These upper limits range from 5.5 to 3.2 pb for Higgs boson masses between 120 and 200 GeV/c{sup 2}.
Date: May 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Search for new physics in lepton + photon + X events with 305 pb**-1 of p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for new physics in lepton + photon + X events with 305 pb**-1 of p anti-p collisions at s**(1/2) = 1.96-TeV

The authors present results of a search for anomalous production of events containing a charged lepton ({ell}, either e or {mu}) and a photon ({gamma}), both with high transverse momentum, accompanied by additional signatures, X, including missing transverse energy (E{sub T}) and additional leptons and photons. We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb{sup -1}, a p{bar p} collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 {ell}{gamma}E{sub T} events versus a standard model expectation of 37.3 {+-} 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 {+-} 0.7 events (corresponding to a 2.7{sigma} effect), is not supported by the new data. In the signature of {ell}{ell}{gamma} + X we observe 31 events versus an expectation of 23.0 {+-} 2.7 events. In this sample we find no events with an extra photon or E{sub T} and so find no events like the one ee{gamma}{gamma}E{sub T} event observed in Run I.
Date: May 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Top quark mass measurement from dilepton events at CDF II with the matrix-element method (open access)

Top quark mass measurement from dilepton events at CDF II with the matrix-element method

We describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II detector from p{bar p} collisions with {radical}s = 1.96 TeV at the Fermilab Tevatron. The likelihood in top mass is calculated for each event by convoluting the leading order matrix element describing q{bar q} {yields} t{bar t} {yields} b{ell}{nu}{sub {ell}}{bar b}{ell}{prime} {nu}{sub {ell}}, with detector resolution functions. The presence of background events in the data sample is modeled using similar calculations involving the matrix elements for major background processes. In a data sample with integrated luminosity of 340 pb{sup -1}, we observe 33 candidate events and measure M{sub top} = 165.2 {+-} 6.1(stat.) {+-} 3.4(syst.) GeV/c{sup 2}. This measurement represents the first application of this method to events with two charged leptons and is the most precise single measurement of the top quark mass in this channel.
Date: May 1, 2006
Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G. et al.
Object Type: Article
System: The UNT Digital Library
Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2004-2005 Annual Report. (open access)

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2004-2005 Annual Report.

None
Date: May 1, 2006
Creator: Achrod, Stephen; Sandford, Benjamin P. & Hockersmith, Eric E. (National Marine Fisheries Services, Northwest Fisheries Science Center, Fish Ecology Division, Seattle, WA)
Object Type: Report
System: The UNT Digital Library
Measurement of the top quark mass using the template method in the lepton plus jets channel with in situ W ---> j j calibration at CDF-II (open access)

Measurement of the top quark mass using the template method in the lepton plus jets channel with in situ W ---> j j calibration at CDF-II

We report an updated measurement of the top quark mass in the lepton plus jets channel of t{bar t} events from p{bar p} collisions at {radical}s = 1.96 TeV. This measurement uses a dataset with integrated luminosity of 680 pb{sup -1}, containing 360 t{bar t} candidates separated into four subsamples. A top quark mass is reconstructed for each event by using energy and momentum constraints on the top quark pair decay products. We also employ the reconstructed mass of hadronic W boson decays W {yields} jj to constrain in situ the largest systematic uncertainty of the top quark mass measurement: the jet energy scale. Monte Carlo templates of the reconstructed top quark and W boson mass are produced as a function of the true top quark mass and the jet energy scale. The distribution of reconstructed top quark and W boson mass in the data are compared to the Monte Carlo templates using a likelihood fit to obtain: M{sub top} = 173.4 {+-} 2.8 GeV/c{sup 2}.
Date: May 1, 2006
Creator: Adelman, Jahred A.; Arguin, J. F.; Bellettini, G.; Brubaker, E.; Budagov, J.; Chlachidze, G. et al.
Object Type: Report
System: The UNT Digital Library
U.S.-European Union Trade Relations: Issues and Policy Challenges (open access)

U.S.-European Union Trade Relations: Issues and Policy Challenges

This report includes information regarding issues and policy challenges with U.S.-European trade relations. Growing strains, resolving longstanding disputes, and strengthening the multilateral trading system are among topics discussed in this report.
Date: May 1, 2006
Creator: Ahearn, Raymond J.
Object Type: Report
System: The UNT Digital Library
Determination of linear optics functions from TBT data (open access)

Determination of linear optics functions from TBT data

A method for evaluation of coupled optics functions, detection of strong perturbing elements, determination of BPM calibration errors and tilts using turn-by-turn (TBT) data is presented as well as the new version of the Hamiltonian perturbation theory of betatron oscillations the method is based upon. An example of application of the considered method to the Tevatron is given.
Date: May 1, 2006
Creator: Alexahin, Y. & Gianfelice-Wendt, E.
Object Type: Article
System: The UNT Digital Library
Development of a Flexible Computerized Management Infrastructure for a Commercial Nuclear Power Plant (open access)

Development of a Flexible Computerized Management Infrastructure for a Commercial Nuclear Power Plant

The report emphasizes smooth transition from paper-based procedure systems (PBPSs) to computer-based procedure systems (CBPSs) for the existing commercial nuclear power plants in the U.S. The expected advantages and of the transition are mentioned including continued, safe and efficient operation of the plants under their recently acquired or desired extended licenses. The report proposes a three-stage survey to aid in developing a national strategic plan for the transition from PBPSs to CBPSs. It also includes a comprehensive questionnaire that can be readily used for the first stage of the suggested survey.
Date: May 1, 2006
Creator: Ali, Syed Firasat; Hajek, Brian K. & Usman, Shoaib
Object Type: Report
System: The UNT Digital Library
Probing low-x QCD with cosmic neutrinos at the Pierre Auger Observatory (open access)

Probing low-x QCD with cosmic neutrinos at the Pierre Auger Observatory

The sources of the observed ultra-high energy cosmic rays must also generate ultra-high energy neutrinos. Deep inelastic scattering of these neutrinos with nucleons on Earth probe center-of-mass energies {radical}s {approx} 100 TeV, well beyond those attainable at terrestrial colliders. By comparing the rates for two classes of observable events, any departure from the benchmark (unscreened perturbative QCD) neutrino-nucleon cross-section can be constrained. Using the projected sensitivity of the Pierre Auger Observatory to quasi-horizontal showers and Earth-skimming tau neutrinos, we show that a ''Super-Auger'' detector can thus provide an unique probe of strong interaction dynamics.
Date: May 1, 2006
Creator: Anchordoqui, Luis A.; Cooper-Sarkar, Amanda M.; Hooper, Dan & Sarkar, Subir
Object Type: Article
System: The UNT Digital Library
Understanding of decay length resolution and its application to bs mixing (open access)

Understanding of decay length resolution and its application to bs mixing

None
Date: May 1, 2006
Creator: Anzelc, Meghan
Object Type: Article
System: The UNT Digital Library
Practical Considerations for High Spatial and Temporal Resolution Dynamic Transmission Electron Microscopy (open access)

Practical Considerations for High Spatial and Temporal Resolution Dynamic Transmission Electron Microscopy

Although recent years have seen significant advances in the spatial resolution possible in the transmission electron microscope (TEM), the temporal resolution of most microscopes is limited to video rate at best. This lack of temporal resolution means that our understanding of dynamic processes in materials is extremely limited. High temporal resolution in the TEM can be achieved, however, by replacing the normal thermionic or field emission source with a photoemission source. In this case the temporal resolution is limited only by the ability to create a short pulse of photoexcited electrons in the source, and this can be as short as a few femtoseconds. The operation of the photo-emission source and the control of the subsequent pulse of electrons (containing as many as 5 x 10{sup 7} electrons) create significant challenges for a standard microscope column that is designed to operate with a single electron in the column at any one time. In this paper, the generation and control of electron pulses in the TEM to obtain a temporal resolution <10{sup -6} s will be described and the effect of the pulse duration and current density on the spatial resolution of the instrument will be examined. The potential of these …
Date: May 1, 2006
Creator: Armstrong, Michael; Boyden, Ken; Browning, Nigel D.; Campbell, Geoffrey H.; Colvin, Jeffrey D.; DeHope, Bill et al.
Object Type: Article
System: The UNT Digital Library
The Hutto Business Update (Hutto, Tex.), Vol. 2, No. 3, Ed. 1 Monday, May 1, 2006 (open access)

The Hutto Business Update (Hutto, Tex.), Vol. 2, No. 3, Ed. 1 Monday, May 1, 2006

Bimonthly newsletter focusing on information for and about the business community in Hutto, Texas, along with advertising.
Date: May 1, 2006
Creator: Arnett, Mahlon E., II
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Meeting the Renewable Energy Challenge: What Will it Take to Reach Solar PV's Ultimate Potential (open access)

Meeting the Renewable Energy Challenge: What Will it Take to Reach Solar PV's Ultimate Potential

Presented at the 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion on May 8, 2006 by Dr. Dan E. Arvizu, Director, National Renewable Energy Laboratory (NREL).
Date: May 1, 2006
Creator: Arvizu, D.
Object Type: Article
System: The UNT Digital Library
Habitat Evaluation Procedures (HEP) Report : Ladd Marsh Wildlife Area, 2004-2006 Technical Report. (open access)

Habitat Evaluation Procedures (HEP) Report : Ladd Marsh Wildlife Area, 2004-2006 Technical Report.

The Regional HEP Team (RHT) and Oregon Department of Fish and Wildlife (ODFW) staff conducted a follow-up habitat evaluation procedures (HEP) analysis on the Ladd Marsh Wildlife Management Area (LMWA) in May 2005. The 2005 HEP assessment resulted in a total of 647.44 HUs, or 0.76 HUs/acre. This is an increase of 420.34 HUs (0.49 HUs/acre) over 2001 HEP survey results. The most significant increase in HUs occurred on the Wallender and Simonis parcels which increased by 214.30 HUs and 177.49 HUs respectively. Transects were established at or near 2001 HEP analysis transect locations whenever possible. ODFW staff biologists assisted the RHT re-establish transect locations and/or suggested areas for new surveys. Since 2001, significant changes in cover type acreage and/or structural conditions have occurred due to conversion of agriculture cover types to emergent wetland and grassland cover types. Agricultural lands were seeded to reestablish grasslands and wetlands were restored through active management and manipulation of extant water sources including natural stream hydrology/flood regimes and available irrigation. Grasslands increased on the Wallender parcel by 21% (65 acres), 23% (71 acres) at the Simonis site, and 39% (62 acres) at Conley Lake. The emergent wetland cover type also changed significantly increasing 60% …
Date: May 1, 2006
Creator: Ashley, Paul & Wagoner, Sara
Object Type: Report
System: The UNT Digital Library
Oklahoma Firefighter (Oklahoma City, Okla.), Vol. 23, No. 4, Ed. 1 Monday, May 1, 2006 (open access)

Oklahoma Firefighter (Oklahoma City, Okla.), Vol. 23, No. 4, Ed. 1 Monday, May 1, 2006

Monthly periodical from Oklahoma City, Oklahoma published by and for members of the Oklahoma State Firefighters Association that includes news and information along with advertising.
Date: May 1, 2006
Creator: Bain, Chris
Object Type: Journal/Magazine/Newsletter
System: The Gateway to Oklahoma History
Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants (open access)

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications is being developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. Previously we described a particle-in-binder approach to immobilizing the potassium salt of the molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the tips of optical fibers. Compared to previous methods, the particle-in-binder approach affords fibers with greatly improved mechanical properties. The response of the sensor to oxygen at 40, 70 and 100 C was measured in 2-21% gas phase oxygen. The normalized sensor signal is linear with molar oxygen concentration and fits the theoretical Stern-Volmer relationship. Although the sensitivity decreases with temperature, at 100 C the sensitivity is 160 [O{sub 2}]{sup -1}. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.
Date: May 1, 2006
Creator: Baker, Gregory L.; Ghosh, Ruby N.; III, D.J. Osborn & Zhang, Po
Object Type: Report
System: The UNT Digital Library
Oxygen Transport Ceramic Membranes (open access)

Oxygen Transport Ceramic Membranes

In this quarter a systematic analysis on the decomposition behavior of the OTM membranes at air and nitrogen were initiated to understand the structural and stoichiometric changes associated with elevated temperatures. Evaluation of the flexural strengths using 4-point bend test was also started for the dual phase membranes. Initial results on the synthesis of dual phase composite materials have been obtained. The measurements have focused on the compatibility of mixed conductors with the pure ionic conductors yttria stabilized zirconia (YSZ) and gadolinium doped ceria (GDC). The initial results obtained for three different mixed conductors suggest that (GDC) is the better choice. A new membrane permeation system has been designed and tested and sintering studies of biphasic systems are in progress.
Date: May 1, 2006
Creator: Bandopadhyay, S.; Nithyanantham, T.; Zhou, X.-D; Sin, Y-W.; Anderson, H.U.; Jacobson, Alan et al.
Object Type: Report
System: The UNT Digital Library
Fermilab Main Injector Beam Position Monitor Upgrade (open access)

Fermilab Main Injector Beam Position Monitor Upgrade

An upgrade of the Beam Position Monitor (BPM) signal processing and data acquisition system for the Fermilab Main Injector is described. The Main Injector is a fast cycling synchrotron that accelerates protons or antiprotons from 8 to 150 GeV. Each Main Injector cycle can have a totally different magnet ramp, RF frequency configuration, beam bunch structure, and injection/extraction pattern from the previous cycle. The new BPM system provides the capabilities and flexibility required by the dynamic and complex machine operations. The system offers measurement capability in the 2.5 MHz and 53 MHz channels to detect the range of bunch structures for protons and antiprotons in both wideband (turn-by-turn) and narrowband (closed-orbit) modes. The new BPM read-out system is based on the digital receiver concept and is highly configurable, allowing the signal processing of nearly all Main Injector beam conditions, including the detection of individual batches. An overview of the BPM system in the Main Injector operating environment, some technology details and first beam measurements are presented.
Date: May 1, 2006
Creator: Banerjee, B.; Barker, W.; Bledsoe, S.; Boes, T.; Briegel, C.; Capista, D. et al.
Object Type: Article
System: The UNT Digital Library