Resource Type

Language

2\beta + \gamma from B^0 to D^\mp K^0 \pi^\pm Decays at BaBar: aSimulation Study (open access)

2\beta + \gamma from B^0 to D^\mp K^0 \pi^\pm Decays at BaBar: aSimulation Study

The authors present the results of a simulation study to perform the extraction of 2{beta} + {gamma} from B{sup 0} {yields} D{sup {-+}}K{sup 0}{pi}{sup {+-}} decays through a time-dependent Dalitz analysis of BaBar data.
Date: April 16, 2007
Creator: Polci, Francesco; Schune, Marie-Helene; Stocchi, Achille & /Orsay, LAL
System: The UNT Digital Library
Abelian Hidden Sectors at a GeV (open access)

Abelian Hidden Sectors at a GeV

We discuss mechanisms for naturally generating GeV-scale hidden sectors in the context of weak-scale supersymmetry. Such low mass scales can arise when hidden sectors are more weakly coupled to supersymmetry breaking than the visible sector, as happens when supersymmetry breaking is communicated to the visible sector by gauge interactions under which the hidden sector is uncharged, or if the hidden sector is sequestered from gravity-mediated supersymmetry breaking. We study these mechanisms in detail in the context of gauge and gaugino mediation, and present specific models of Abelian GeV-scale hidden sectors. In particular, we discuss kinetic mixing of a U(1){sub x} gauge force with hypercharge, singlets or bi-fundamentals which couple to both sectors, and additional loop effects. Finally, we investigate the possible relevance of such sectors for dark matter phenomenology, as well as for low- and high-energy collider searches.
Date: April 16, 2009
Creator: Morrissey, David E.; Poland, David; U., /Harvard; Zurek, Kathryn & U., /Fermilab /Michigan
System: The UNT Digital Library
Analysis of the impact of energy crops on water quality. Final report (open access)

Analysis of the impact of energy crops on water quality. Final report

This report consists of two separate papers. The first, ``The potential use of agricultural simulation models in predicting the fate of nitrogen and pesticides applied to switchgrass and poplars,`` describes three models (CREAMS, GLEAMS, and EPIC) for the evaluation of the relationships which determine water quality in the agroecosystem. Case studies are presented which demonstrate the utility of these models in evaluating the potential impact of alternative crop management practices. The second paper, ``Energy crops as part of a sustainable landscape,`` discusses concepts of landscape management and the linkage among agricultural practices and environmental quality.
Date: April 16, 1993
Creator: Hatfield, J. L. & Gale, W. J.
System: The UNT Digital Library
Analytical capabilities of RIMS: absolute sensitivity and isotopic analysis. [Resonance ionization mass spectrometry] (open access)

Analytical capabilities of RIMS: absolute sensitivity and isotopic analysis. [Resonance ionization mass spectrometry]

The cw laser RIMS approach has been demonstrated to accurately measure large Lu isotope ratios and detect small levels of minor isotopes even in the presence of isobaric interferences. The same approach can also be used to obtain high resolution optical spectra of rare isotopes. For elements with higher ionization potentials (e.g., Tc), multicolor ionization schemes are necessary for cw RIMS measurements. Two-color RIMS spectra of Tc using pulsed lasers illustrate the feasibility of this approach. For any element, the sensitivity and selectivity of RIMS can be limited by the efficiency of ground state atom production in the sample volatilization step.
Date: April 16, 1984
Creator: Nogar, N. S.; Downey, S. W. & Miller, C. M.
System: The UNT Digital Library
Applications of gamma-ray spectrometry in the quantitative nondestructive assay of special nuclear materials (open access)

Applications of gamma-ray spectrometry in the quantitative nondestructive assay of special nuclear materials

Nearly all applications of gamma-ray spectrometry in the quanitative assay of special nuclear materials can be grouped into five general categories. They are as follows: (1) Quanitative passive assay, of which transmission-corrected passive assay methods for measuring isotopic masses/concentrations are an important subset; (2) Enrichment measurements on infinitely thick'' samples for absolute determination of isotopic fractions/concentrations; (3) Measurements of isotopic ratios using relative detection efficiency principles resulting in absolute isotopic distributions without recourse to standards; (4) Absorption-edge densitometry measurements of elemental concentrations; and (5) X-ray fluorescence measurements of elemental concentrations. Careful and correct practice of these techniques can yield measurement accuracies in the range of 0.1% to 1.0% in favorable situations with measurement times generally in the range of 15 minutes to 1 hour. We present examples of these general categories with emphasis on those measurements and techniques exhibiting the best accuracy, as well as those which are not routinely practiced in many other applications of gamma-ray spectrometry. 20 refs., 6 fig.
Date: April 16, 1990
Creator: Sampson, Thomas E. & Parker, Jack L.
System: The UNT Digital Library
Applications of Photonuclear Physics for International Safeguards and Security (open access)

Applications of Photonuclear Physics for International Safeguards and Security

Studies of nuclear resonance fluorescence based applications are presented. Important for these applications are data for isotopes such as {sup 239}Pu. Nuclear resonance fluorescence measurements of {sup 239}Pu were performed at the free electron laser facility at UC Santa Barbara using photons from a bremsstrahlung beam with an endpoint energies between 4.0 MeV and 5.5 MeV. Though no discrete states with significant confidence level were measured, we have excluded the region above 27(3) eV-barns, or 4-sigma, where we would expect only a small chance of false positives. Details of the measurements and the results are presented here.
Date: April 16, 2010
Creator: Johnson, M. S.; Hall, J. M.; McNabb, D. P.; McFarland, J.; Norman, E.; Bertozzi, W. et al.
System: The UNT Digital Library
Applied and Environmental Microbiology Gordon Research Conference July 27 - August 1, 2003 (open access)

Applied and Environmental Microbiology Gordon Research Conference July 27 - August 1, 2003

None
Date: April 16, 2004
Creator: Wall, Judy D.
System: The UNT Digital Library
The Astro-E2 XRS/EBIT Microcalorimeter XC-ray Spectrometer (open access)

The Astro-E2 XRS/EBIT Microcalorimeter XC-ray Spectrometer

The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare XRS microcalorimeter spectrometer at the EBIT-I and SuperEBIT facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolving power. The XRS microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully engineering the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration 'library' for the Astro-E2 observatory.
Date: April 16, 2004
Creator: Porter, F S; Brown, G V; Boyce, K R; Kelley, R L; Kilbourne, C A; Beiersdorfer, P et al.
System: The UNT Digital Library
Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation (open access)

Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation

The asymmetric intramolecular alkylation of chiral aromatic aldimines, in which differentially substituted alkenes are tethered meta to the imine, was investigated. High enantioselectivities were obtained for imines prepared from aminoindane derivatives, which function as directing groups for the rhodium-catalyzed C-H bond activation. Initial demonstration of catalytic asymmetric intramolecular alkylation also was achieved by employing a sterically hindered achiral imine substrate and catalytic amounts of a chiral amine.
Date: April 16, 2007
Creator: Watzke, Anja; Wilson, Rebecca; O'Malley, Steven; Bergman, Robert & Ellman, Jonathan
System: The UNT Digital Library
BAM: A Block-Based Bayesian Method for Detecting Genome-Wide Associations with Multiple Diseases (open access)

BAM: A Block-Based Bayesian Method for Detecting Genome-Wide Associations with Multiple Diseases

Article proposes a novel Bayesian method, named BAM, for simultaneously partitioning Single Nucleotide Polymorphisms (SNPs) into Linkage Disequilibrium(LD)-blocks and detecting genome-wide multi-locus epistatic interactions that are associated with multiple diseases. Experimental results on the simulated datasets demonstrate that BAM is powerful and efficient.
Date: April 16, 2020
Creator: Guo, Xuan; Wu, Guanying & Xu, Baohua
System: The UNT Digital Library
Branching Fraction and Charge Asymmetry Measurements inB to J/psi pi pi Decays (open access)

Branching Fraction and Charge Asymmetry Measurements inB to J/psi pi pi Decays

The authors study the decays B{sup 0} {yields} J/{psi} {pi}{sup +}{pi}{sup -} and B{sup +} {yields} J/{psi} {pi}{sup +}{pi}{sup 0}, including intermediate resonances, using a sample of 382 million B{bar B} pairs recorded by the BABAR detector at the PEP-II e{sup +}e{sup -} B factory. They measure the branching fractions {Beta}(B{sup 0} {yields} J/{psi} {rho}{sup 0}) = (2.7 {+-} 0.3 {+-} 0.17) x 10{sup -5} and {Beta}(B{sup +} {yields} J/{psi} {rho}{sup +}) = (5.0 {+-} 0.7 {+-} 0.31) x 10{sup -5}. The authors also set the following upper limits at the 90% confidence level: {Beta}(B{sup 0} {yields} J/{psi} {pi}{sup +}{pi}{sup -} non-resonant) < 1.2 x 10{sup -5}, {Beta}(B{sup 0} {yields} J/{psi} f{sub 2}) < 4.6 x 10{sup -6}, and {Beta}(B{sup +} {yields} J/{psi} {pi}{sup +}{pi}{sup 0} non-resonant) < 4.4 x 10{sup -6}. They measure the charge asymmetry in charged B decays to J/{psi} {rho} to be -0.11 {+-} 0.12 {+-} 0.08.
Date: April 16, 2007
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
System: The UNT Digital Library
Building a programmable interface for physics codes using numeric python (open access)

Building a programmable interface for physics codes using numeric python

With its portability, ease to add built-in functions and objects in C, and fast array facility among many other features, Python proved to be an excellent language for creating programmable scientific applications. In addition to the two modules presented, there are also other progresses at LLNL in using Python. For example, Python interfaces are being developed for at least three graphics packages, and Python interpreter and applications have been built on distributed platforms such as meiko and Cray T3D.
Date: April 16, 1996
Creator: Yang, T.-Y.B.; Dubois, P.F. & Motteler, Z.C.
System: The UNT Digital Library
Cause of pitting in beryllium (open access)

Cause of pitting in beryllium

Light microscopy, bare-film radiography, secondary ion mass spectroscopy, electron microprobe and physical testing were used to examine beryllium specimens exhibiting a stratified, pitted, pattern after chemical milling. The objective was to find the cause of this pattern. Specimens were found to have voids in excess of density specification allowances. These voids are attributed, at least in part, to the sublimation of beryllium fluoride during the vacuum hot pressing operation. The origin of the pattern is attributed to these voids and etching out of fines and associated impurities. Hot isostatic pressing with a subsequent heat treatment close residual porosity and dispersed impurities enough to correct the problem.
Date: April 16, 1982
Creator: Kershaw, R. P.
System: The UNT Digital Library
Chromaticity control in the Fermilab Main Injector (open access)

Chromaticity control in the Fermilab Main Injector

Chromaticity control in the Fermilab Main Injector will be important both in accelerating protons and antiprotons from 8 GeV to 150 GeV (or 120 GeV) and in decelerating recycled 150 GeV antiprotons to 8 GeV for storage in the Recycler Ring. The Main Injector has two families of sextupoles to control the chromaticity. In addition to the natural chromaticity, they must correct for sextupole fields from ramp-rate-dependent eddy currents in the dipole beampipes and current-dependent sextupole fields in the dipole magnets. The horizontal sextupole family is required to operate in a bipolar mode below the transition energy of 20 GeV. We describe methods used to control chromaticities in the Fermilab Main Injector. Emphasis is given to the software implementation of the operator interface to the front-end ramp controllers. Results of chromaticity measurements and their comparison with the design model will be presented.
Date: April 16, 1999
Creator: al., G. Wu et
System: The UNT Digital Library
Comparative Study of Bunch Length And Arrival Time Measurements at Flash (open access)

Comparative Study of Bunch Length And Arrival Time Measurements at Flash

Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At FLASH, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure, but the method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. It is therefore complemented by two non-disruptive electrooptical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into the spatial dimension of the laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.
Date: April 16, 2007
Creator: Schlarb, H.; Azima, A.; Dusterer, S.; Huning, M.; Knabbe, E.A.; Roehrs, M. et al.
System: The UNT Digital Library
Convergent evolution in primates and an insectivore (open access)

Convergent evolution in primates and an insectivore

The cardiovascular risk factor apolipoprotein(a) (apo(a)) has a puzzling distribution among mammals, its presence being limited to a subset of primates and a member of the insectivore lineage, the hedgehog. To explore the evolutionary history of apo(a), we performed extensive genomic sequence comparisons of multiple species with and without an apo(a) gene product, such as human, baboon, hedgehog, lemurand mouse. This analysis indicated that apo(a) arose independently in a subset of primates, including baboon and human, and an insectivore, the hedgehog, and was not simply lost by species lacking it. The similar structural domains shared by the hedgehog and primate apo(a) indicate that they were formed by a unique molecular mechanism involving the convergent evolution of paralogous genes in these distantspecies.
Date: April 16, 2003
Creator: Boffelli, Dario; Cheng, Jan-Fang & Rubin, Edward M.
System: The UNT Digital Library
Correlation between Strand Stability and Magnet Performance (open access)

Correlation between Strand Stability and Magnet Performance

Magnet programs at BNL, LBNL and FNAL have observed instabilities in high J{sub c} Nb{sub 3}Sn strands and magnets made from these strands. This paper correlates the strand stability determined from a short sample-strand test to the observed magnet performance. It has been observed that strands that carry high currents at high fields (greater than 10T) cannot sustain these same currents at low fields (1-3T) when the sample current is fixed and the magnetic field is ramped. This suggests that the present generation of strand is susceptible to flux jumps (FJ). To prevent flux jumps from limiting stand performance, one must accommodate the energy released during a flux jump. To better understand FJ this work has focused on wire with a given sub-element diameter and shows that one can significantly improve stability by increasing the copper conductivity (higher residual resistivity ratio, RRR, of the Cu). This increased stability significantly improves the conductor performance and permits it to carry more current.
Date: April 16, 2005
Creator: Dietderich, Daniel R.; Bartlett, Scott E.; Caspi, Shlomo; Ferracin, Paolo; G ourlay, Stephen A.; Higley, Hugh C. et al.
System: The UNT Digital Library
CP violation at CDF (open access)

CP violation at CDF

A major goal of experimental particle physics over the next decade is to measure the sides and angles of the Unitarity triangle redundantly, and as precisely as possible. Overconstraining the triangle will test the Cabbibo-Kobayashi-Maskawa model of quark mixing. The CDF collaboration, due to begin a second run in March 2001 with major upgrades to both the accelerator and the detector, will study the angle {beta} using B{sup 0} decays, the angle {gamma} using B{sup 0} and B{sub s}{sup 0} decays, and a side of the triangle through the observation of B{sub s}{sup 0}--{bar B}{sub s}{sup 0} mixing. Projected sensitivities are driven mostly by previous measurements using data from the first run. One highlight of the Run I B physics program is a measurement of the CP violating parameter sin 2{beta} = 0.79{sub {minus}0.44}{sup +0.41}, based on a tagged sample of 400 B{sup 0} decays in the mode B{sub 0}/{bar B}{sup 0} {r_arrow} J/{psi}K{sub s}{sup 0}. The technology of flavor tagging, used here as well as in numerous B{sup 0}-{bar B}{sup 0} mixing analyses in run I, is crucial and will be augmented in Run II with better particle identification capabilities. Exclusive all-hadronic final states will enter the data sample …
Date: April 16, 2001
Creator: Boudreau, J.
System: The UNT Digital Library
CRBR reactor structures design. BRC meeting presentation (open access)

CRBR reactor structures design. BRC meeting presentation

None
Date: April 16, 1975
Creator: Pennell, W.E.
System: The UNT Digital Library
Crystal structure of bis(acetonitrile-𝖪N)(4,4'-di-tert-butyl-2,2'-bipyridine-𝖪²N,N')platinum(II) bis(tetra-fluoridoborate) packing as head-to-head dimers (open access)

Crystal structure of bis(acetonitrile-𝖪N)(4,4'-di-tert-butyl-2,2'-bipyridine-𝖪²N,N')platinum(II) bis(tetra-fluoridoborate) packing as head-to-head dimers

This article describes the crystal structure of a platinum(II) supramolecular building block, [Pt-(dbbpy)NNCCH₃)₂](BF₄)₂ (dbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine, C₁₈H₂₄N₂).
Date: April 16, 2018
Creator: Joseph, Chris; Nesterov, Vladimir N. & Smucker, Bradley W.
System: The UNT Digital Library
Data warehousing, metadata, and the World Wide Web (open access)

Data warehousing, metadata, and the World Wide Web

The connection between data warehousing and the metadata. used to catalog and locate warehouse data is obvious, but what is the connection between data warehousing, metadata, and the World Wide Web (WWW)? Specifically, the WWW can be used to allow users to search metadata (data about the data) and retrieve data from a warehouse database. In addition, the Internet/Intranet can be used to manage the metadata in archive databases and to streamline the database administration functions of a large archive center. The Oak Ridge National Laboratory`s (ORNL`s) Distributed Active Archive Center (DAAC) is a data archive and distribution center for the National Air and Space Administration`s (NASA`s) Earth Observing System Data and Information System (EOSDIS); the ORNL DAAC provides access to tabular and imagery datasets used in ecological and environmental research. To support this effort, we have taken advantage of the rather unique and user-friendly features of the WWW to (1) allow users to search for and download the data we archive and (2) provide DAAC developers with effective metadata and data management tools. In particular, the ORNL DAAC has developed the Biogeochemical Information Ordering Management Environment (BIOME), a WWW search-and-order system, as well as a WWW-based database administrator`s (DBA`s) …
Date: April 16, 1997
Creator: Yow, T.G.; Smith, A.W. & Daugherty, P.F.
System: The UNT Digital Library
Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope (open access)

Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope

The Tracker subsystem of the Large Area Telescope (LAT) science instrument of the Gamma-ray Large Area Space Telescope (GLAST) mission has been completed and tested. It is the central detector subsystem of the LAT and serves both to convert an incident gamma-ray into an electron-positron pair and to track the pair in order to measure the gamma-ray direction. It also provides the principal trigger for the LAT. The Tracker uses silicon strip detectors, read out by custom electronics, to detect charged particles. The detectors and electronics are packaged, along with tungsten converter foils, in 16 modular, high-precision carbon-composite structures. It is the largest silicon-strip detector system ever built for launch into space, and its aggressive design emphasizes very low power consumption, passive cooling, low noise, high efficiency, minimal dead area, and a structure that is highly transparent to charged particles. The test program has demonstrated that the system meets or surpasses all of its performance specifications as well as environmental requirements. It is now installed in the completed LAT, which is being prepared for launch in early 2008.
Date: April 16, 2007
Creator: Atwood, W.B.; Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F. et al.
System: The UNT Digital Library
Design and operation of a rapid thermal transient component testing sodium loop (open access)

Design and operation of a rapid thermal transient component testing sodium loop

A specific problem developed during the design of an on-line sampling system for the Sodium Loop Safety Facility fast breeder reactor experiments. Rapid fluctuations in the sodium temperature, caused by reactor operation and shutdown, exposed the system components to conditions that could result in fatigue failure. A component test loop was designed and built at the Idaho National Engineering Laboratory to allow experimental qualification of component integrity. This paper outlines test system requirements, describes the design and special features, presents test procedures ad relates significant operating experience.
Date: April 16, 1984
Creator: Crandall, D. L.
System: The UNT Digital Library
Design of the ILC Prototype FONT4 Digital Intra-Train Beam-Based Feedback System (open access)

Design of the ILC Prototype FONT4 Digital Intra-Train Beam-Based Feedback System

We present the design of the FONT4 digital intra-train beam position feedback system prototype and preliminary results of initial beam tests at the Accelerator Test Facility (ATF) at KEK. The feedback system incorporates a fast analogue beam position monitor (BPM) front-end signal processor, a digital feedback board, and a kicker driver amplifier. The short bunchtrain, comprising 3 electron bunches separated by c. 150ns, in the ATF extraction line was used to test components of the prototype feedback system.
Date: April 16, 2007
Creator: Burrows, P.; /Queen Mary, U. of London; Christian, G. B.; Hartin, A. F.; Dabiri Khah, H.; White, G. R. et al.
System: The UNT Digital Library