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Search for the Rare Decays B+ to D(*)+K0s
The authors report on the search for the rare decays B{sup +} {yields} D{sup (*)+} K{sub s}{sup 0} in approximately 226 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEp-II asymmetric-energy B factory at SLAC. They do not observe any significant signal and they set 90% confidence level upper limits on the branching fractions, {Beta}(B{sup +} {yields} D{sup +}K{sup 0}) < 0.5 x 10{sup -5} and {Beta}(B{sup +} {yields} D*{sup +} K{sup 0}) < 0.9 x 10{sup -5}.
Date:
June 2, 2005
Creator:
Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurements of B to {pi, eta, eta'} l nu Branching Fractions andDetermination of |Vub| with Semileptonically Tagged B Mesons
The authors report measurements of branching fractions for the decays B {yields} P{ell}{nu}{sub {ell}}, where P are the pseudoscalar charmless mesons {pi}{sup -}, {pi}{sup 0}, {eta} and {eta}{prime}, based on 348 fb{sup -1} of data collected with the BABAR detector, using B{sup 0} and B{sup +} mesons found in the recoil of a second B meson decaying as B {yields} D{sup (*)}{ell}{nu}{sub {ell}}. Assuming isospin symmetry, they combine pionic branching fractions to obtain {Beta}(B{sup 0} {yields} {pi}{sup -} {ell}{sup +} {nu}{sub {ell}}) = (1.54 {+-} 0.17{sub (stat)} {+-} 0.09{sub (syst)}) x 10{sup -4}; they find 3.2{sigma} evidence of the decay B{sup +} {yields} {eta}{ell}{sup +}{nu}{sub {ell}} and measure its branching fraction to be (0.64 {+-} 0.20{sub (stat)} {+-} 0.3{sub (syst)}) x 10{sup -4}, and determine {Beta}(B{sup +} {yields} {eta}{prime}{ell}{sup +}{nu}{sub {ell}}) < 0.47 x 10{sup -4} to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a recent form factor calculation, they obtain the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}| = (4.0 {+-} 0.5{sub (stat)} {+-} 0.2{sub (syst){sub -0.5}{sup +0.7}(theory)}) x 10{sup -3}.
Date:
June 2, 2008
Creator:
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type:
Article
System:
The UNT Digital Library
The Genetically Remote Pathogenic Strain NVH391-98 of the Bacillus cereus Group Represents the Cluster of Thermophilic Strains
Bacteria of the Bacillus cereus group are known to cause food poisoning. A rare phylogenetically remote strain, NVH391-98, was recently characterized to encode a particularly efficient cytotoxin K presumably responsible for food poisoning. This pathogenic strain and its close relatives can be phenotypically distinguished from other strains of the B. cereus group by the inability to grow at temperatures below 17 degrees C and by the ability to grow at temperatures from 48 to 53 degrees C. A temperate phage, phBC391A2, residing in the genome of NVH391-98 allows us to distinguish the three known members of this thermophilic strain cluster.
Date:
October 2, 2007
Creator:
Auger, Sandrine; Galleron, Nathalie; Bidnenko, Elena; Ehrlich, S. Dusko; Lapidus, Alla & Sorokin, Alexei
Object Type:
Article
System:
The UNT Digital Library
Fast Implementation of Matched Filter Based Automatic Alignment Image Processing
Video images of laser beams imprinted with distinguishable features are used for alignment of 192 laser beams at the National Ignition Facility (NIF). Algorithms designed to determine the position of these beams enable the control system to perform the task of alignment. Centroiding is a common approach used for determining the position of beams. However, real world beam images suffer from intensity fluctuation or other distortions which make such an approach susceptible to higher position measurement variability. Matched filtering used for identifying the beam position results in greater stability of position measurement compared to that obtained using the centroiding technique. However, this gain is achieved at the expense of extra processing time required for each beam image. In this work we explore the possibility of using a field programmable logic array (FPGA) to speed up these computations. The results indicate a performance improvement of 20 using the FPGA relative to a 3 GHz Pentium 4 processor.
Date:
April 2, 2008
Creator:
Awwal, A. S.; Rice, K. & Taha, T.
Object Type:
Article
System:
The UNT Digital Library
Efficient traffic grooming in SONET/WDM BLSR Networks
In this paper, we study traffic grooming in SONET/WDM BLSR networks under the uniform all-to-all traffic model with an objective to reduce total network costs (wavelength and electronic multiplexing costs), in particular, to minimize the number of ADMs while using the optimal number of wavelengths. We derive a new tighter lower bound for the number of wavelengths when the number of nodes is a multiple of 4. We show that this lower bound is achievable. All previous ADM lower bounds except perhaps that in were derived under the assumption that the magnitude of the traffic streams (r) is one unit (r = 1) with respect to the wavelength capacity granularity g. We then derive new, more general and tighter lower bounds for the number of ADMs subject to that the optimal number of wavelengths is used, and propose heuristic algorithms (circle construction algorithm and circle grooming algorithm) that try to minimize the number of ADMs while using the optimal number of wavelengths in BLSR networks. Both the bounds and algorithms are applicable to any value of r and for different wavelength granularity g. Performance evaluation shows that wherever applicable, our lower bounds are at least as good as existing bounds …
Date:
April 2, 2004
Creator:
Awwal, Abdul S.; Billah, Abdur R. B. & Wang, Bin
Object Type:
Article
System:
The UNT Digital Library
Applications of Lie Groups and Gauge Functions to the Construction of Exact Difference Equations for Initial and Two-Point Boundary Value Problems
New methods are developed to construct exact difference equations from which numerical solutions of both initial value problems and two-point boundary value problems involving first and second order ordinary differential equations can be computed. These methods are based upon the transformation theory of differential equations and require the identification of symmetry properties of the differential equations. The concept of the divergence-invariance of a variational principle is also applied to the construction of difference equations. It is shown how first and second order ordinary differential equations that admit groups of point transformations can be integrated numerically by constructing any number of exact difference equations.
Date:
August 2, 2002
Creator:
Axford, R.
Object Type:
Report
System:
The UNT Digital Library
Exploring little Higgs models with ATLAS at the LHC
We discuss possible searches for the new particles predicted by Little Higgs Models at the LHC. By using a simulation of the ATLAS detector, we demonstrate how the predicted quark, gauge bosons and additional Higgs bosons can be found and estimate the mass range over which their properties can be constrained.
Date:
February 2, 2004
Creator:
Azuelos, G.; Benslama, K.; Costanzo, D.; Couture, G.; Garcia, J.E.; Hinchliffe, I.G. et al.
Object Type:
Article
System:
The UNT Digital Library
FIRST STEPS INTO AN ENERGY EFFECIENT FUTURE
Red Lake Band of Chippewa Indians proposes to develop a more sustainable, affordable and autonomous energy future for Tribal Members. The Band will develop the capacity to conduct energy audits, to implement energy efficiency measures in tribal homes, and to build more energy efficient housing. This will be done by providing direct classroom and on the job training for Tribal members to conduct the energy audits and the installation of insulation.
Date:
April 2, 2009
Creator:
BARRETT, JANE L.
Object Type:
Report
System:
The UNT Digital Library
GCMS Analyses of Chemical Vapor Deposition Precursors
None
Date:
October 2, 2000
Creator:
BARTRAM,MICHAEL E.
Object Type:
Article
System:
The UNT Digital Library
Effect of Te Inclusions on Internal Electric Field of CdMnTe Gamma-Ray Detectors
We studied two separate as-grown CdMnTe crystals by Infrared (IR) microscopy and Pockels effect imaging, and then developed an algorithm to analyze and visualize the electric field within the crystals’ bulk. In one of the two crystals the size and distribution of inclusions within the bulk promised to be more favorable in terms of efficiency as a detector crystal. However, the Te inclusions were arranged in characteristic ‘planes’. Pockels imaging revealed an accumulation of charges in the region of these planes. We demonstrated that the planes induced stress within the bulk of the crystal that accumulated charges, thereby causing non-uniformity of the internal electric field and degrading the detector’s performance.
Date:
August 2, 2009
Creator:
Babalola, O.S.; Bolotnikov, A.; Egarievwe, S.; Hossain, A.; Burger, A. & James, R.
Object Type:
Article
System:
The UNT Digital Library
U.S. Linear Collider Technology Options Study
None
Date:
June 2, 2006
Creator:
Bagger, J
Object Type:
Report
System:
The UNT Digital Library
ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.
The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.
Date:
October 2, 2006
Creator:
Bai, M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; Beebe-Wang, J.; Blaskiewicz, M. et al.
Object Type:
Article
System:
The UNT Digital Library
RHIC Vertical AC Dipole Commissioning
The RHIC vertical ac dipole was installed in the summer of 2001. The magnet is located in the interaction region between sector 3 and sector 4 common to both beams. The resonant frequency of the ac dipole was first configured to be around half of the beam revolution frequency to act as a spin flipper. At the end of the RHIC 2002 run, the ac dipole frequency was reconfigured for linear optics studies. A 0.35 mm driven betatron oscillation was excited with the vertical ac dipole and the vertical betatron functions and phase advances at each beam position monitor (BPM) around the RHIC yellow ring were measured using the excited coherence. We also recorded horizontal turn-by-turn beam positions at each BPM location to investigate coupling effects. Analysis algorithms and measurement results are presented.
Date:
June 2, 2002
Creator:
Bai, M.; DeLong, J.; Hoff, L.; Pai, C.; Peggs, S.; Piacentino, J. et al.
Object Type:
Article
System:
The UNT Digital Library
RHIC Spin Flipper Commissioning.
An ac dipole with horizontally oriented oscillating magnetic field (spin flipper) was installed in FU-IIC to reverse the spin direction in the presence of two full Siberian snakes, thereby reducing the systematic errors for the spin physics experiments in RHIC. With two full snakes, the spin vector completes one full precession around the vertical direction in two revolutions, and the spin depolarization resonances due to the machine imperfections and betatron oscillations are eliminated. Since the spin flipper provides an oscillating horizontal dipole field, a ''spin resonance'' can occur if the spin flipper frequency is placed in the neighborhood of the spin precession frequency [ 1,2,3]. By slowly sweeping the spin flipper frequency across the spin precession frequency, a full spin flip can be achieved. This paper reports the results of the FZUC spin flipper commissioned during the RHIC 2002 polarized proton run. By running the spin flipper at a slightly different configuration, one can also measure the spin precession tune.
Date:
June 2, 2002
Creator:
Bai, M.; MacKay, W. W.; Ranjbar, V. & Roser, T.
Object Type:
Article
System:
The UNT Digital Library
Level-2 Milestone 2351: Terascale Simulation Facility Upgrade
This report documents the LLNL TSF upgrade ASC L2 milestone 2351: Terascale Simulation Facility upgrade, due Sept. 30, 2007. The full text of the milestone is included in Attachment 1. The stated goal of the milestone was: 'Complete a 3-MW expansion of electrical power for computing systems in the east computer room of the Terascale Simulation Facility (TSF) and complete the final connection of all air handlers that were delivered as part of the TSF line item'. In this report we detail the upgrade and cover the results of the process to accept the system by testing, adjusting, balancing and finally start-up of the system in accordance with the detailed project commissioning plan to be developed by the system engineers during the design phase of the project. The quarterly reports for the upgrade and the text of the project commissioning plan are included at the end of this document as Attachments 2 and 3.
Date:
October 2, 2007
Creator:
Bailey, A M
Object Type:
Report
System:
The UNT Digital Library
Finding General Explicit Formulas for Ising Integral Recursions
None
Date:
October 2, 2006
Creator:
Bailey, D. H. & Borwein, J. M.
Object Type:
Report
System:
The UNT Digital Library
How to Find More Supernovae with Less Work: Object ClassificationTechniques for Difference Imaging
We present the results of applying new object classificationtechniques to difference images in the context of the Nearby SupernovaFactory supernova search. Most current supernova searches subtractreference images from new images, identify objects in these differenceimages, and apply simple threshold cuts on parameters such as statisticalsignificance, shape, and motionto reject objects such as cosmic rays,asteroids, and subtraction artifacts. Although most static objectssubtract cleanly, even a very low false positive detection rate can leadto hundreds of non-supernova candidates which must be vetted by humaninspection before triggering additional followup. In comparison to simplethreshold cuts, more sophisticated methods such as Boosted DecisionTrees, Random Forests, and Support Vector Machines provide dramaticallybetter object discrimination. At the Nearby Supernova Factory, we reducedthe number of non-supernova candidates by a factor of 10 while increasingour supernova identification efficiency. Methods such as these will becrucial for maintaining a reasonable false positive rate in the automatedtransient alert pipelines of upcoming projects such as PanSTARRS andLSST.
Date:
May 2, 2007
Creator:
Bailey, Stephen; Aragon, Cecilia; Romano, Raquel; Thomas, RollinC.; Weaver, Benjamin A. & Wong, Daniel
Object Type:
Article
System:
The UNT Digital Library
Growth of thick, crystalline material using dc-magnetron sputtering in Mag1 deposition chamber
We demonstrated dense, non-columnar growth of thick Mo films by moving the substrates in and out of the plasma thus allowing the surface reconstruction and by interrupting the growth with Si layers. The multilayers made this way have very smooth surface, about 1.3 nm rms high spatial frequency roughness, while also maintaining the periodicity of a reflective coating. These preliminary results hint that the surface reconstruction is an important physical process that controls the growth mechanisms. Further studies, combined with theoretical modeling, are essential to further our knowledge on how to predict and control desired microstructure for different materials.
Date:
November 2, 2005
Creator:
Bajt, S; Alameda, J; Baker, S & Taylor, J S
Object Type:
Report
System:
The UNT Digital Library
Conceptual Models of Flow through a Heterogeneous, Layered Vadose Zone under a Percolation Pond
Understanding how water and solutes move through the vadose zone is necessary to make effective remedial action decisions where contaminants were spilled or leaked at the ground surface or were buried in shallow land-disposal sites. In layered, heterogeneous systems, high contrasts in hydraulic conductivity can lead to formation of perched water zones, and enhanced lateral spread of contamination. Two conceptual models are considered solute for migration through the vadose zone. In the diffuse flow conceptual model, perched water zones accumulate until the head over the perching layer becomes sufficient to drive the infiltration through the perching layer. In the preferential flow conceptual model, perched water moves laterally until a path around the perching layer is encountered. Preferential flow paths can enhance contaminant migration because greater moisture saturation leads to higher advective velocities, and the preferential flow paths bypass low permeability layers with higher sorption capacity. Monitoring wells and instrumented boreholes were installed around a newly constructed industrial-waste percolation pond and an ephemeral river that lie over a 150-m-thick layered vadose zone. Background data gathered before discharge to the pond began show the presence of at least one, and possibly two, deep perched zones. The shallower zone, at approximately 45-m below …
Date:
February 2, 2004
Creator:
Baker, Kristine; Hull, Larry; Bennett, Jesse; Ansley, Shannon & Heath, Gail
Object Type:
Report
System:
The UNT Digital Library
Group Representations and Multinomial Combinatorics of the Icosahedral Symmetry
The icosahedral symmetry is one of the most intriguing symmetries, as it not only presents challenge but it appears in many fullerenes and high energetic materials such as the dodecahedral N{sub 20}. We have considered the combinatorics of all irreducible representations of the icosahedral symmetry for a number of multinomial partitions for vertex, face and edge colorings in this work. We have constructed the combinatorial tables for all irreducible representations for various multinomial partitions of colorings for the vertices, edge and faces of the icosahedron. These techniques should have important applications to enumerations and spectroscopy of fullerenes and high-energy materials such as N{sub 20}.
Date:
February 2, 2004
Creator:
Balasubramanian, K
Object Type:
Article
System:
The UNT Digital Library
Non-rigid Group Theory, Tunneling Splittings and Nuclear Spin Statistics of Water Pentamer: (H2O5)
The character table of the fully non-rigid water pentamer, (H{sub 2}O){sub 5} is derived for the first time. The group of all feasible permutations is the wreath product group S{sub 5}[S{sub 2}] and it consists of 3840 operations divided into 36 conjugacy classes and irreducible representations. We have shown that the full character table can be constructed using elegant matrix type generator algebra. The character table has been applied to the water pentamer by obtaining the nuclear spin statistical weights of the rovibronic levels and tunneling splittings of the fully non-rigid pentamer. We have also obtained the statistical weights and tunneling splittings of a semi-rigid deuterated pentamer that exhibits pseudo rotation with an averaged C{sub 5h}(G{sub 10}) symmetry used in the assignment of vibration-rotation-tunneling spectra . The correlation tables have been constructed for the semirigid (G{sub 10}) to non-rigid (G{sub 3840}) groups for the rotational levels and tunneling levels. The nuclear spin statistical weights have also been derived for both the limits.
Date:
February 2, 2004
Creator:
Balasubramanian, K
Object Type:
Article
System:
The UNT Digital Library
Damage Mechanisms of Filled Siloxanes for Predictive Multiscale Modeling of Aging Behavior
Predictions of component performance versus lifetime are often risky for complex materials in which there may be many underlying aging or degradation mechanisms. In order to develop more accurate predictive models for silica-filled siloxane components, we are studying damage mechanisms over a broad range of size domains, linked together through several modeling efforts. Atomistic and molecular dynamic modeling has elucidated the chemistry of the silica filler to polymer interaction, as this interaction plays a key role in this material's aging behavior. This modeling work has been supported by experimental data on the removal of water from the silica surface, the effect of the surrounding polymer on this desiccation, and on the subsequent change in the mechanical properties of the system. Solid State NMR efforts have characterized the evolution of the polymer and filler dynamics as the material is damaged through irradiation or desiccation. These damage signatures have been confirmed by direct measurements of changes in polymer crosslink density and filler interaction as measured by solvent swelling, and by mechanical property tests. Data from the changes at these molecular levels are simultaneously feeding the development of age-aware constitutive models for polymer behavior. In addition, the microstructure of the foam, including under …
Date:
April 2, 2002
Creator:
Balazs, B; Maxwell, R; de Teresa, S; Dinh, L & Gee, R
Object Type:
Article
System:
The UNT Digital Library
Low-budget muon source
Generation of muon beams with protons on a current-carrying target followed by a lithium lens and a quadrupole decay channel is considered. A 8 GeV proton beam from the Fermilab Booster is used to provide a muon beam for the MUCOOL experiment for ionization cooling demonstration. The proposed scheme can also be used to create muon beams with a fraction of a 1 GeV proton beam of the Spallation Neutron Source. Monte Carlo simulations of the entire system are performed. For both cases optimization of the target and matching lithium lens is done. It is shown that such a set followed by an inexpensive decay channel based on quadrupole magnets with and without RF cavities provides a rather intense bunched muon beam.
Date:
July 2, 2001
Creator:
Balbekov, Valeri I. & Mokhov, Nikolai V.
Object Type:
Article
System:
The UNT Digital Library
An Assessment of Technologies to Provide Extended Sludge Retrieval from Underground Storage Tanks at the Hanford Site
The purpose of this study was to identify sludge mobilization technologies that can be readily installed in double-shell tanks along with mixer pumps to augment mixer pump operation when mixer pumps do not adequately mobilize waste. The supplementary technologies will mobilize sludge that may accumulate in tank locations out-of-reach of the mixer-pump jet and move the sludge into the mixer-pump range of operation. The identified technologies will be evaluated to determine if their performances and configurations are adequate to meet requirements developed for enhanced sludge removal systems. The study proceeded in three parallel paths to identify technologies that: (1) have been previously deployed or demonstrated in radioactive waste tanks, (2) have been specifically evaluated for their ability to mobilize or dislodge waste simulants with physical and theological properties similar to those anticipated during waste retrieval, and (3) have been used in similar industrial conditions, bu t not specifically evaluated for radioactive waste retrieval.
Date:
August 2, 2000
Creator:
Bamberger, JA
Object Type:
Report
System:
The UNT Digital Library