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 production cross section in p{bar p} collisions at {radical}s = 1.96 TeV utilizing 425 pb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-p{sub T} electron or muon and at least four jets. We exploit specific kinematic features of t{bar t} events to extract the cross section. For a top quark mass of 175 GeV, we measure {sigma}{sub t{bar t}} = 6.4{sub -1.2}{sup +1.3}(stat) {+-} 0.7(syst) {+-} 0.4(lum)pb, in good agreement with the standard model prediction.
Date: May 1, 2007
Creator: Abazov, V.
Object Type: Article
System: The UNT Digital Library
Observation and Properties of L = 1 B(1) and B*(2) Mesons (open access)

Observation and Properties of L = 1 B(1) and B*(2) Mesons

None
Date: May 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 stopped gluinos from p-anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Search for stopped gluinos from p-anti-p collisions at s**(1/2) = 1.96-TeV

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino ({tilde g}), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb{sup -1} of p{bar p} collisions at sqrt(s)=1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such 'stopped gluinos' decaying into a gluon and a neutralino ({tilde {chi}}{sub 1}{sup 0}). Limits are placed on the (gluino cross section)x(probability to stop)x[BR({tilde g}{yields}g {tilde {chi}}{sub 1}{sup 0<})] as a function of the gluino and {tilde {chi}}{sub 1}{sup 0<} masses, for gluino lifetimes from 30 {micro}s-100 h.
Date: May 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
Z gamma production and limits on anomalous Z Z gamma and Z gamma gamma couplings in panti-p collisions at s**(1/2) = 1.96- TeV (open access)

Z gamma production and limits on anomalous Z Z gamma and Z gamma gamma couplings in panti-p collisions at s**(1/2) = 1.96- TeV

None
Date: May 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
First observation of K(L) ---> pi+- e-+ nu e+ e- (open access)

First observation of K(L) ---> pi+- e-+ nu e+ e-

None
Date: May 1, 2007
Creator: Abouzaid, E.; Arenton, M.; Barker, A. R.; Bellantoni, L.; Blucher, E.; Bock, G. J. et al.
Object Type: Article
System: The UNT Digital Library
Applying Agile Methods to Weapon/Weapon-Related Software (open access)

Applying Agile Methods to Weapon/Weapon-Related Software

This white paper provides information and guidance to the Department of Energy (DOE) sites on Agile software development methods and the impact of their application on weapon/weapon-related software development. The purpose of this white paper is to provide an overview of Agile methods, examine the accepted interpretations/uses/practices of these methodologies, and discuss the applicability of Agile methods with respect to Nuclear Weapons Complex (NWC) Technical Business Practices (TBPs). It also provides recommendations on the application of Agile methods to the development of weapon/weapon-related software.
Date: May 2, 2007
Creator: Adams, Dennis; Armendariz, Maria; Blackledge, Mike; Campbell, Frank; Cloninger, Mack; Cox, Larry et al.
Object Type: Report
System: The UNT Digital Library
MOBILE SYSTEMS FOR DILUTION OF HIGHLY ENRICHED URANIUM AND URANIUM CONTAINING COMPONENTS (open access)

MOBILE SYSTEMS FOR DILUTION OF HIGHLY ENRICHED URANIUM AND URANIUM CONTAINING COMPONENTS

A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed. The process utilizes a closed system approach to retain fission products/gases inside a sealed canister after treatment. The MMD process melts and dilutes spent fuel with depleted uranium to obtain a fissile fraction of less than 0.2. The final ingot is solidified inside the sealed canister and can be stored safely either wet or dry until final disposition or reprocessing. The MMD module can be staged at or near the research reactor fuel storage sites to facilitate the melt-dilute treatment of the spent fuel into a stable non-proliferable form.
Date: May 2, 2007
Creator: Adams, T
Object Type: Article
System: The UNT Digital Library
Searches for new phenomena with lepton final states at the Tevatron (open access)

Searches for new phenomena with lepton final states at the Tevatron

Numerous searches for new phenomena have been carried out using data from proton-antiproton collisions at Fermilab's Tevatron. Final states with leptons give signatures which are relatively unique and generally have small backgrounds. We present many of the latest results from the CDF and D0 collaborations from 0.4-1.2 fb{sup -1} of data. Topics include supersymmetry, extra gauge bosons, Randall-Sundrum gravitons, excited electrons and neutral, long-lived particles.
Date: May 1, 2007
Creator: Adams, T.
Object Type: Article
System: The UNT Digital Library
Verification Survey of the Building 315 Zero Power Reactor-6 Facility, Argonne National Laboratory-East, Argonne, Illinois (open access)

Verification Survey of the Building 315 Zero Power Reactor-6 Facility, Argonne National Laboratory-East, Argonne, Illinois

Oak Ridge Institute for Science and Education (ORISE) conducted independent verification radiological survey activities at Argonne National Laboratory’s Building 315, Zero Power Reactor-6 facility in Argonne, Illinois. Independent verification survey activities included document and data reviews, alpha plus beta and gamma surface scans, alpha and beta surface activity measurements, and instrumentation comparisons. An interim letter report and a draft report, documenting the verification survey findings, were submitted to the DOE on November 8, 2006 and February 22, 2007, respectively (ORISE 2006b and 2007).
Date: May 25, 2007
Creator: Adams, W. C.
Object Type: Report
System: The UNT Digital Library
Measurement of the atmospheric muon charge ratio at TeV energies with MINOS (open access)

Measurement of the atmospheric muon charge ratio at TeV energies with MINOS

The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}}+/N{sub {mu}}-=1.374{+-}0.004(stat)-0.010{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.
Date: May 1, 2007
Creator: Adamson, P.; Andreopoulos, C.; Arms, K.E.; Armstrong, R.; Auty, D.J.; Avvakumov, S. et al.
Object Type: Article
System: The UNT Digital Library

Biomass and Biofuels: Technology and Economic Overview

Presentation on biomass and biofuels technology and economics presented at Pacific Northwest National Laboratory, May 23, 2007.
Date: May 23, 2007
Creator: Aden, Andy
Object Type: Presentation
System: The UNT Digital Library
Topological Strings And (Almost) Modular Forms (open access)

Topological Strings And (Almost) Modular Forms

The B-model topological string theory on a Calabi-Yau threefold X has a symmetry group {Lambda}, generated by monodromies of the periods of X. This acts on the topological string wave function in a natural way, governed by the quantum mechanics of the phase space H{sup 3}(X). We show that, depending on the choice of polarization, the genus g topological string amplitude is either a holomorphic quasi-modular form or an almost holomorphic modular form of weight 0 under {Lambda}. Moreover, at each genus, certain combinations of genus g amplitudes are both modular and holomorphic. We illustrate this for the local Calabi-Yau manifolds giving rise to Seiberg-Witten gauge theories in four dimensions and local IP{sub 2} and IP{sub 1} x IP{sub 1}. As a byproduct, we also obtain a simple way of relating the topological string amplitudes near different points in the moduli space, which we use to give predictions for Gromov-Witten invariants of the orbifold C{sub 3}/ZZ{sub 3}.
Date: May 4, 2007
Creator: Aganagic, Mina; Bouchard, Vincent & Klemm, Albrecht
Object Type: Article
System: The UNT Digital Library
Structural and Magnetothermal Properties of Compounds: Yb5SixGe4-x,Sm5SixGe4-x, EuO, and Eu3O4 (open access)

Structural and Magnetothermal Properties of Compounds: Yb5SixGe4-x,Sm5SixGe4-x, EuO, and Eu3O4

The family of R{sub 5}Si{sub x}Ge{sub 4-x} alloys demonstrates a variety of unique physical phenomena related to magneto-structural transitions associated with reversible breaking and reforming of specific bonds that can be controlled by numerous external parameters such as chemical composition, magnetic field, temperature, and pressure. Therefore, R{sub 5}Si{sub x}Ge{sub 4-x} systems have been extensively studied to uncover the mechanism of the extraordinary magneto-responsive properties including the giant magnetoresistance (GMR) and colossal magnetostriction, as well as giant magnetocaloric effect (GMCE). Until now, more than a half of possible R{sub 5}Si{sub x}Ge{sub 4-x} pseudobinary systems have been completely or partially investigated with respect to their crystallography and phase relationships (R = La, Pr, Nd, Gd, Tb, Dy, Er, Lu, Y). Still, there are other R{sub 5}Si{sub x}Ge{sub 4-x} systems (R = Ce, Sm, Ho, Tm, and Yb) that are not studied yet. Here, we report on phase relationships and structural, magnetic, and thermodynamic properties in the Yb{sub 5}Si{sub x}Ge{sub 4-x} and Sm{sub 5}Si{sub x}Ge{sub 4-x} pseudobinary systems, which may exhibit mixed valence states. The crystallography, phase relationships, and physical properties of Yb{sub 5}Si{sub x}Ge{sub 4-x} alloys with 0 {le} x {le} 4 have been examined by using single crystal and powder x-ray …
Date: May 9, 2007
Creator: Ahn, Kyunghan
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Supersymmetry in Particle Physics - An Elementary Introduction (open access)

Supersymmetry in Particle Physics - An Elementary Introduction

None
Date: May 11, 2007
Creator: Aitchison, I.J.R. & /Oxford U., Theor. Phys. /SLAC
Object Type: Report
System: The UNT Digital Library
Global Cooling: Effect of Urban Albedo on Global Temperature (open access)

Global Cooling: Effect of Urban Albedo on Global Temperature

In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in …
Date: May 22, 2007
Creator: Akbari, Hashem; Menon, Surabi & Rosenfeld, Arthur
Object Type: Article
System: The UNT Digital Library
Laser heating of solid matter by light pressure-driven shocks (open access)

Laser heating of solid matter by light pressure-driven shocks

Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D particle-in-cell (PIC) simulations suggest that the surface heating is due to a light pressure driven shock.
Date: May 4, 2007
Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.
Object Type: Article
System: The UNT Digital Library
2006 B100 Quality Survey Results: Milestone Report (open access)

2006 B100 Quality Survey Results: Milestone Report

In 2006, the National Renewable Energy Laboratory conducted a nationwide quality survey of pure biodiesel (B100) intended to be used as a blendstock. The study collected random samples throughout the United States and analyzed them for quality against the current and proposed ASTM D6751 fuel quality specifications.
Date: May 1, 2007
Creator: Alleman, T. L.; McCormick, R. L. & Deutch, S.
Object Type: Report
System: The UNT Digital Library
Current Renewable Energy Technologies and Future Projections (open access)

Current Renewable Energy Technologies and Future Projections

The generally acknowledged sources of renewable energy are wind, geothermal, biomass, solar, hydropower, and hydrogen. Renewable energy technologies are crucial to the production and utilization of energy from these regenerative and virtually inexhaustible sources. Furthermore, renewable energy technologies provide benefits beyond the establishment of sustainable energy resources. For example, these technologies produce negligible amounts of greenhouse gases and other pollutants in providing energy, and they exploit domestically available energy sources, thereby reducing our dependence on both the importation of fossil fuels and the use of nuclear fuels. The market price of renewable energy technologies does not reflect the economic value of these added benefits.
Date: May 1, 2007
Creator: Allison, Stephen W.; Lapsa, Melissa Voss; Ward, Christina D.; Smith, Barton; Grubb, Kimberly R. & Lee, Russell
Object Type: Report
System: The UNT Digital Library
Final Technical Report: Development of the DUSTRAN GIS-Based Complex Terrain Model for Atmospheric Dust Dispersion (open access)

Final Technical Report: Development of the DUSTRAN GIS-Based Complex Terrain Model for Atmospheric Dust Dispersion

Activities at U.S. Department of Defense (DoD) training and testing ranges can be sources of dust in local and regional airsheds governed by air-quality regulations. The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the DoD in addressing particulate air-quality issues at military training and testing ranges.
Date: May 1, 2007
Creator: Allwine, K Jerry; Rutz, Frederick C.; Shaw, William J.; Rishel, Jeremy P.; Fritz, Brad G.; Chapman, Elaine G. et al.
Object Type: Report
System: The UNT Digital Library
Puzzling differences in bismuth and lead plasmas: evidence for thesignificant role of neutrals in cathodic vacuum arcs (open access)

Puzzling differences in bismuth and lead plasmas: evidence for thesignificant role of neutrals in cathodic vacuum arcs

Time-dependent ion charge state measurements for Pb and Bicathodic arc plasmas revealed unexpectedly strong differences: the meanBi ion charge state dropped much stronger and with a longer time constantthan the mean Pb ion charge state. It is shown that the difference inthermal conductivity led to much higher vapor pressure for Bi, which inturn much more effectively caused charge exchange collisions. The resultshave implications beyond Pb and Bi plasmas, most importantly that the"true" charge states as emitted from the cathode spot are higher thanwhat is generally measured and published.
Date: May 10, 2007
Creator: Anders, Andre & Yushkov, Georgy Yu.
Object Type: Article
System: The UNT Digital Library
Production of Neutrals and Their and Effects on the Ion Chargestates in Cathodic Vacuum Arc Plasmas (open access)

Production of Neutrals and Their and Effects on the Ion Chargestates in Cathodic Vacuum Arc Plasmas

Cathodic arc plasmas are considered fully ionized and theycontain multiply charged ions, yet, gaseous and metal neutrals can bepresent. It is shown that they can cause a significant reduction of theion charge states as measured far from the cathode spots. Several cathodematerials were used to study the evolution the mean ion charge state as afunction of time after arc ignition. The type of cathode material, arccurrent amplitude, intentionally increased background gas, additionalsurfaces placed near the plasma flow, and other factors influence thedegree of charge state reduction because all of these factors influencethe density of neutrals. In all cases, it was found that the mean ioncharge state follows an exponential decay of first order, Q(t) = A *exp(t/tau) + Qss, where A is a parameter describing the importance of thedecay, tau is the characteristic decay time, and Qss is a steady-statevalue approached for continuous arc operation. The extrapolated valuesQ(t-->0) indicate surprisingly high mean charge states as produced atcathode spots and not "skewed" by charge exchange collisions withneutrals.
Date: May 23, 2007
Creator: Anders, Andre; Oks, Efim M. & Yushkov, Georgy Yu.
Object Type: Article
System: The UNT Digital Library
Microsecond delays on non-real time operating systems (open access)

Microsecond delays on non-real time operating systems

We have developed microsecond timing and profiling software that runs on standard Windows and Linux based operating systems. This software is orders of magnitudes better than most of the standard native functions in wide use. Our software libraries calibrate RDTSC in microseconds or seconds to provide two different types of delays: a ''Guaranteed Minimum'' and a precision ''Long Delay'', which releases to the kernel. Both return profiling information of the actual delay.
Date: May 1, 2007
Creator: Angstadt, R.; Estrada, J.; Diehl, H. T.; Flaugher, B. & Johnson, M.
Object Type: Article
System: The UNT Digital Library
FUNDAMENTAL SAFETY TESTING AND ANALYSIS OF HYDROGEN STORAGE MATERIALS AND SYSTEMS (open access)

FUNDAMENTAL SAFETY TESTING AND ANALYSIS OF HYDROGEN STORAGE MATERIALS AND SYSTEMS

Hydrogen is seen as the future automobile energy storage media due to its inherent cleanliness upon oxidation and its ready utilization in fuel cell applications. Its physical storage in light weight, low volume systems is a key technical requirement. In searching for ever higher gravimetric and volumetric density hydrogen storage materials and systems, it is inevitable that higher energy density materials will be studied and used. To make safe and commercially acceptable systems, it is important to understand quantitatively, the risks involved in using and handling these materials and to develop appropriate risk mitigation strategies to handle unforeseen accidental events. To evaluate these materials and systems, an IPHE sanctioned program was initiated in 2006 partnering laboratories from Europe, North America and Japan. The objective of this international program is to understanding the physical risks involved in synthesis, handling and utilization of solid state hydrogen storage materials and to develop methods to mitigate these risks. This understanding will support ultimate acceptance of commercially high density hydrogen storage system designs. An overview of the approaches to be taken to achieve this objective will be given. Initial experimental results will be presented on environmental exposure of NaAlH{sub 4}, a candidate high density hydrogen …
Date: May 1, 2007
Creator: Anton, D
Object Type: Article
System: The UNT Digital Library
Arsenic pilot plant operation and results:Weatherford, Oklahoma. (open access)

Arsenic pilot plant operation and results:Weatherford, Oklahoma.

Narasimhan Consulting Services, Inc. (NCS), under a contract with the Sandia National Laboratories (SNL), designed and operated pilot scale evaluations of the adsorption and coagulation/filtration treatment technologies aimed at meeting the recently revised arsenic maximum contaminant level (MCL) for drinking water. The standard of 10 {micro}g/L (10 ppb) is effective as of January 2006. The pilot demonstration is a project of the Arsenic Water Technology Partnership program, a partnership between the American Water Works Association Research Foundation (AwwaRF), SNL and WERC (A Consortium for Environmental Education and Technology Development). The pilot evaluation was conducted at Well 30 of the City of Weatherford, OK, which supplies drinking water to a population of more than 10,400. Well water contained arsenic in the range of 16 to 29 ppb during the study. Four commercially available adsorption media were evaluated side by side for a period of three months. Both adsorption and coagulation/filtration effectively reduced arsenic from Well No.30. A preliminary economic analysis indicated that adsorption using an iron oxide media was more cost effective than the coagulation/ filtration technology.
Date: May 1, 2007
Creator: Aragon, Malynda Jo; Arora, H. (Narasimhan Consulting Services Inc., Phoenix, Arizona); Karori, Saqib (Narasimhan Consulting Services Inc., Phoenix, Arizona) & Pathan, Sakib (Narasimhan Consulting Services Inc., Phoenix, Arizona)
Object Type: Report
System: The UNT Digital Library