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830 Matching Results

Start Over Year 2009 Day 23rd

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(open access)

Staffing for Adequate Fire and Emergency Response: The SAFER Grant Program

The Staffing for Adequate Fire and Emergency Response Act (the "SAFER Act") was enacted by the 108th Congress as part of the FY2004 National Defense Authorization Act. This report describes the SAFER Act in brief and discusses possible budgetary modifications to the SAFER Act that are being considered due to the recent economic downturn.

Date: June 23, 2009

Creator: Kruger, Lennard G.

Object Type: Report

System: The UNT Digital Library

(open access)

China-U.S. Trade Issues

U.S.-China economic ties have expanded substantially over the past three decades. With a huge population and a rapidly expanding economy, China is a potentially huge market for U.S. exporters. However, bilateral economic relations have become strained over a number of issues, which this report discusses at length. The current global economic crisis could further challenge China-U.S. economic ties. Several Members of Congress have urged the Obama Administration to take a more assertive approach in dealing with Chinese economic practices.

Date: June 23, 2009

Creator: Morrison, Wayne M.

Object Type: Report

System: The UNT Digital Library

(open access)

Oil Spills in U.S. Coastal Waters: Background, Governance, and Issues for Congress

This report reviews the history and trends of oil spills in the United States; identifies the legal authorities governing oil spill prevention, response, and cleanup; and examines the threats of future oil spills in U.S. coastal waters.

Date: April 23, 2009

Creator: Ramseur, Jonathan L.

Object Type: Report

System: The UNT Digital Library

(open access)

United States Fire Administration: An Overview

The U.S. Fire Administration (USFA) - which includes the National Fire Academy (NFA) - is currently an entity within the Federal Emergency Management Agency (FEMA) of the Department of Homeland Security (DHS). The objective of the USFA is to significantly reduce the nation's loss of life from fire, while also achieving a reduction in property loss and non-fatal injury due to fire. In the 111th Congress, debate over the USFA budget focuses on whether the USFA is receiving sufficient funding to accomplish its mission, given that appropriations for USFA have consistently been well below the agency's authorized level. An ongoing issue is the viability and status of the USFA and National Fire Academy within the Department of Homeland Security.

Date: June 23, 2009

Creator: Kruger, Lennard G.

Object Type: Report

System: The UNT Digital Library

(open access)

The 2009 Influenza Pandemic: U.S. Responses to Global Human Cases

This report discusses the April 2009 outbreak of the influenza strain known as H1N1, or commonly, swine influenza. This report describes the distribution of the virus and the statistics of affected areas, as well as international and U.S. efforts to treat infected persons, respond to outbreaks in various countries (such as Mexico and other Latin American nations), and prepare for a possible influenza pandemic.

Date: June 23, 2009

Creator: Salaam-Blyther, Tiaji

Object Type: Report

System: The UNT Digital Library

(open access)

Measurement of the Semileptonic Decays B->D tau nu and B->D* tau nu

The authors present measurements of the semileptonic decays B{sup -} {yields} D{sup 0} {tau}{sup -} {bar {nu}}{sub {tau}}, B{sup -} {yields} D*{sup 0} {tau}{sup -}{bar {nu}}{sub {tau}}, {bar B}{sup 0} {yields} D{sup +} {tau}{sup -} {bar {nu}}{sub {tau}}, and {bar B}{sup 0} {yields} D*{sup +} {tau}{sup -}{bar {nu}}{sub {tau}}, which are sensitive to non-Standard Model amplitudes in certain scenarios. The data sample consists of 232 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider. They select events with a D or D* meson and a light lepton ({ell} = e or {mu}) recoiling against a fully reconstructed B meson. They perform a fit to the joint distribution of lepton momentum and missing mass squared to distinguish signal B {yields} D{sup (*)}{tau}{sup -} {bar {nu}}{sub {tau}} ({tau}{sup -} {yields} {ell}{sup -} {bar {nu}}{sub {ell}}{nu}{sub {tau}}) events from the backgrounds, predominantly B {yields} D{sup (*)} {ell}{sup -}{bar {nu}}{sub {ell}}. They measure the branching-fraction ratios R(D) {triple_bond} {Beta}(B {yields} D{tau}{sup -} {bar {nu}}{sub {tau}})/{Beta}(B {yields} D{ell}{sup -} {bar {nu}}{sub {ell}}) and R(D*) {triple_bond} {Beta}(B {yields} D*{tau}{sup -} {bar {nu}}{sub {tau}})/{Beta}(B {yields} D* {ell}{sup -} {bar {nu}}{sub {ell}}) and, from a combined fit …

Date: February 23, 2009

Creator: Aubert, B.

Object Type: Article

System: The UNT Digital Library

(open access)

Metastable Supersymmetry Breaking and Multitrace Deformations of SQCD

Metastable vacua in supersymmetric QCD in the presence of single and multitrace deformations of the superpotential are explored, with the aim of obtaining an acceptable phenomenology. The metastable vacua appear at one loop, have a broken R-symmetry, and a magnetic gauge group that is completely Higgsed. With only a single trace deformation, the adjoint fermions from the meson superfield are approximately massless at one loop, even though they are massive at tree level and R-symmetry is broken. Consequently, if charged under the standard model, they are unacceptably light. A multitrace quadratic deformation generates fermion masses proportional to the deformation parameter. Phenomenologically viable models of direct gauge mediation can then be obtained, and some of their features are discussed.

Date: February 23, 2009

Creator: Essig, Rouven; Fortin, Jean-Francois; Sinha, Kuver; Torroba, Gonzalo & Strassler, Matthew J.

Object Type: Article

System: The UNT Digital Library

(open access)

Simulating SiD Calorimetry: Software Calibration Procedures and Jet Energy Resolution

Simulated calorimeter performance in the SiD detector is examined. The software calibration procedures are described, as well as the perfect pattern recognition PFA reconstruction. Performance of the SiD calorimeters is summarized with jet energy resolutions from calorimetry only, perfect pattern recognition and the SiD PFA algorithm. Presented at LCWS08[1]. Our objective is to simulate the calorimeter performance of the SiD detector, with and without a Particle Flow Algorithm (PFA). Full Geant4 simulations using SLIC[2] and the SiD simplified detector geometry (SiD02) are used. In this geometry, the calorimeters are represented as layered cylinders. The EM calorimeter is Si/W, with 20 layers of 2.5mm W and 10 layers of 5mm W, segmented in 3.5 x 3.5mm{sup 2} cells. The HAD calorimeter is RPC/Fe, with 40 layers of 20mm Fe and a digital readout, segmented in 10 x 10mm{sup 2} cells. The barrel detectors are layered in radius, while the endcap detectors are layered in z(along the beam axis).

Date: February 23, 2009

Creator: Cassell, Ron

Object Type: Article

System: The UNT Digital Library

(open access)

Response Time Measurements of the NIF DANTE XRD-31 X-Ray Diodes (Pre-print)

The XRD-31 is a fast, windowless X-ray vacuum photodiode developed by EG&G. It is currently the primary fast X-ray detector used to diagnose the X-rays on NIF and OMEGA on the multichannel DANTE spectrometer. The XRD-31 has a dynamic range of less than 1e-12 amps to more than 10 amps. A technique is described to measure the impulse response of the diodes to a 150 fs pulse of 200 nm laser light and a method to calculate the “risetime” for a square pulse and compare it with the computed electron transit time from the photocathode to the anode. Measured response time for 5 XRD-31s assembled in early 2004 was 149.7 ps +-2.75 ps.

Date: January 23, 2009

Creator: Griffin, Don Pellinen and Michael

Object Type: Article

System: The UNT Digital Library

$Search for the decay B^+ \to K_S^0 K_S^0 \pi ^+$ (open access)

Search for the decay B^+ \to K_S^0 K_S^0 \pi ^+

The authors search for charmless decays of charged B mesons to the three-body final state K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup +}. Using a data sample of 423.7 fb{sup -1} collected at the {Upsilon}(4S) resonance with the BABAR detector, corresponding to (465.1 {+-} 5.1) x 10{sup 6} B{bar B} pairs, they find no significant signal and determine a 90% confidence level upper limit on the branching fraction of 5.1 x 10{sup -7}.

Date: February 23, 2009

Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Life Cost Based FMEA Manual: A Step by Step Guide to Carrying Out a Cost-based Failure Modes and Effects Analysis

Failure occurs when one or more of the intended functions of a product are no longer fulfilled to the customer's satisfaction. The most critical product failures are those that escape design reviews and in-house quality inspection and are found by the customer. The product may work for a while until its performance degrades to an unacceptable level or it may have not worked even before customer took possession of the product. The end results of failures which may lead to unsafe conditions or major losses of the main function are rated high in severity. Failure Modes and Effects Analysis (FMEA) is a tool widely used in the automotive, aerospace, and electronics industries to identify, prioritize, and eliminate known potential failures, problems, and errors from systems under design, before the product is released (Stamatis, 1997). Several industrial FMEA standards such as those published by the Society of Automotive Engineers, US Department of Defense, and the Automotive Industry Action Group employ the Risk Priority Number (RPN) to measure risk and severity of failures. The Risk Priority Number (RPN) is a product of 3 indices: Occurrence (O), Severity (S), and Detection (D). In a traditional FMEA process design engineers typically analyze the 'root …

Date: January 23, 2009

Creator: Rhee, Seung; Spencer, Cherrill & /SLAC, /Stanford U.

Object Type: Report

System: The UNT Digital Library

(open access)

EMSL Fiscal Year 2008 Annual Report

This annual report provides details on the research conducted at EMSL--the Environmental Molecular Sciences Laboratory in Fiscal Year 2008.

Date: January 23, 2009

Creator: Showalter, Mary Ann

Object Type: Report

System: The UNT Digital Library

(open access)

Effects of Energy Chirp on Echo-Enabled Harmonic Generation Free-Electron Lasers

We study effects of energy chirp on echo-enabled harmonic generation (EEHG). Analytical expressions are compared with numerical simulations for both harmonic and bunching factors. We also discuss the EEHG free-electron laser bandwidth increase due to an energy-modulated beam and its pulse length dependence on the electron energy chirp.

Date: February 23, 2009

Creator: Huang, Z.; Ratner, D.; Stupakov, G. & Xiang, D.

Object Type: Report

System: The UNT Digital Library

(open access)

Precise Predictions for W + 3 Jet Production at Hadron Colliders

We report on the first next-to-leading order QCD computation of W + 3-jet production in hadronic collisions including all partonic subprocesses. We compare the results with CDF data from the Tevatron, and find excellent agreement. The renormalization and factorization scale dependence is reduced substantially compared to leading-order calculations. The required one-loop matrix elements are computed using on-shell methods, implemented in a numerical program, BlackHat. We use the SHERPA package to generate the real-emission contributions and to integrate the various contributions over phase space. We use a leading-color (large-N{sub c}) approximation for the virtual part, which we confirm in W + 1,2-jet production to be valid to within three percent. The present calculation demonstrates the utility of on-shell methods for computing next-to-leading-order corrections to processes important to physics analyses at the Large Hadron Collider.

Date: February 23, 2009

Creator: Berger, C.F.; /MIT, LNS; Bern, Z.; /UCLA; Dixon, L.J.; /SLAC et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Dalitz Plot Analysis of B+- --> pi+-pi+-pi-+ Decays

The authors present a Dalitz-plot analysis of charmless B{sup {+-}} decays to the final state {pi}{sup {+-}}{pi}{sup {+-}}{pi}{sup {-+}} using a sample of (465 {+-} 5) x 10{sup 6} B{bar B} pairs collected by the BABAR experiment at {radical}s = 10.58 GeV. They measure the branching fractions {Beta}(B{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup {+-}}{pi}{sup {-+}}) = (15.2 {+-} 0.6 {+-} 1.2 {+-} 0.4) x 10{sup -6}, {Beta}(B{sup {+-}} {yields} {rho}{sup 0}(770){pi}{sup {+-}}) = (8.1 {+-} 0.7 {+-} 1.2{sub -1.1}{sup +0.4}) x 10{sup -6}, {Beta}(B{sup {+-}} {yields} f{sub 2}(1270){pi}{sup {+-}}) = (1.57 {+-} 0.42 {+-} 0.16{sub -0.19}{sup +0.53}) x 10{sup -6}, and {Beta}(B{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup {+-}}{pi}{sup {-+}} nonresonant) = (5.3 {+-} 0.7 {+-} 0.6{sub -0.5}{sup +1.1}) x 10{sup -6}, where the uncertainties are statistical, systematic, and model-dependent, respectively. Measurements of branching fractions for the modes B{sup {+-}} {yields} {rho}{sup 0}(1450){pi}{sup {+-}} and B{sup {+-}} {yields} f{sub 0}(1370){pi}{sup {+-}} are also presented. They observe no significant direct CP asymmetries for the above modes, and there is no evidence for the decays B{sup {+-}} {yields} f{sub 0}(980){pi}{sup {+-}}, B{sup {+-}} {yields} {chi}{sub c0}{pi}{sup {+-}}, or B{sup {+-}} {yields} {chi}{sub c2}{pi}{sup {+-}}.

Date: February 23, 2009

Creator: Collaboration, The BABAR & Aubert, B.

Object Type: Article

System: The UNT Digital Library

(open access)

Scalable Methods for Electronic Excitations and Optical Responses of Nanstructures: Mathematics to Algorithms to Observables

This multi-investigator project was concerned with the development and application of new methods and computer codes that would allow realistic modeling of nanosystems. Carter's part in this team effort involved two method/algorithm/code development projects during the first 14 months of this grant. Carter's group has been advancing theory and applications of the orbital-free density functional theory (OF-DFT), the only DFT method that exhibits linear scaling for metals. Such a method offers the possibility of simulating large numbers of atoms with quantum mechanics, such that properties of metallic nanostructures (e.g. nanowires of realistic dimensions) could be investigated. In addition, her group has been developing and applying an embedded correlated wavefunction theory for treating localized excited states in condensed matter (including metals). The application of interest here is spin manipulation at the nanoscale, i.e., spintronics, in which local electron excitations interact with the surrounding material. Her embedded correlation method is ideal for studying such problems.

Date: January 23, 2009

Creator: Carter, Emily A.

Object Type: Report

System: The UNT Digital Library

(open access)

AdS/CFT and Light-Front Holography: A Theory of Strong Interactions

Recent developments in the theory of strong interactions are discussed in the framework of the AdS/CFT duality between string theories of gravity in a higher dimension Anti-de Sitter space and conformal quantum field theories in physical space-time. This novel theoretical approach, combined with 'light-front holography', leads to new insights into the quark and gluon structure of hadrons and a viable first approximation to quantum chromodynamics, the fundamental theory of the strong and nuclear interactions.

Date: February 23, 2009

Creator: Brodsky, Stanley J. & Teramond, Guy F.de

Object Type: Article

System: The UNT Digital Library

(open access)

Matter Dependence of the Three-Loop Soft Anomalous Dimension Matrix

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions, which has been computed through two loops. The two-loop matrix is proportional to the one-loop matrix. Recently there have been proposals that this proportionality extends to higher loops. One can test such proposals by computing the dependence of this matrix on the matter content in a generic gauge theory. It is shown that for the matter-dependent part the proportionality extends to three loops for arbitrary massless processes.

Date: January 23, 2009

Creator: Dixon, Lance J.

Object Type: Article

System: The UNT Digital Library

(open access)

Polarized Photocathode R&D for Future Linear Collliders

It is a challenge to generate full charge electrons from the electron sources without compromising polarization for the proposed ILC and CLIC. It is essential to advance polarized photocathodes to meet the requirements. SLAC has worldwide unique dedicated test facilities, Cathode Test System and dc-Gun Test Laboratory, to fully characterize polarized photocathodes. Recent systematic measurements on a strained-well InAlGaAs/AlGaAs cathode at the facilities show that 87% polarization and 0.3% QE are achieved. The QE can be increased to {approx}1.0% with atomic hydrogen cleaning. The surface charge limit at a very low current intensity and the clear dependence of the polarization on the surface charge limit are observed for the first time. On-going programs to develop photocathodes for the ILC and CLIC are briefly introduced.

Date: January 23, 2009

Creator: Zhou, F; Brachmann, A.; Maruyama, T. & Sheppard, J. C.

Object Type: Article

System: The UNT Digital Library

(open access)

Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha and beta activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion with the relative bias being small compared to the dispersion. By also measuring environmental air sample filters simultaneously with electroplated alpha and beta sources, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations. Use of the current algorithm is therefore not recommended for assay applications and so use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha and beta activities on air sample filters (not due to radon progeny) around the 200 dpm level.

Date: January 23, 2009

Creator: Hayes, Robert

Object Type: Article

System: The UNT Digital Library