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A Study of Factorization and a Measurement of CP Violation

Description: We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{sup 0}{bar B}{sup 0} decays collected between 1999 and 2004, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in … more
Date: January 16, 2008
Creator: Dahmes, Bryan
Partner: UNT Libraries Government Documents Department
open access

A Simultaneous Measurement of the Branching Fractions of Ten B to Double Charm Decays

Description: This dissertation presents a simultaneous measurement of the branching fractions of ten B {yields} D{sup (*)}{bar D}{sup (*)} decays. The measurements are derived from a sample of 2.32 x 10{sup 8} B{bar B} pairs collected by the BABAR detector at the PEP-II B Factory located at Stanford Linear Accelerator Center. The branching fractions (x 10{sup -4}) are: -0.10 {+-} 0.44 {+-} 0.15 (<0.59) for B{sup 0} {yields} D{sup 0}{bar D}{sup 0}; 1.01 {+-} 1.07 {+-} 0.35 (<2.92) for B{sup 0} {yields}… more
Date: January 16, 2008
Creator: Lae, Chung Khim
Partner: UNT Libraries Government Documents Department
open access

Search for Rare Quark-Annihilation Decays, Charged B Mesons Decaying to Charged D(S) Mesons And Phi Mesons

Description: The authors report on a search for the decay B{sup {+-}} {yields} D{sub s}{sup (*){+-}} {phi} using 212.2 fb{sup -1} of data collected with the BABAR detector at the PEP-II B Factory at the Stanford Linear Accelerator Center between 1999 and 2004. This sample of 234 x 10{sup 6} e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} events yields no significant signal. They report the Bayesian upper limits {Beta}(B{sup {+-}} {yields} D{sub s}{sup {+-}} {phi}) x {Beta}(D{sub s}{sup {+-}} {yiel… more
Date: January 16, 2008
Creator: Cunha, J.Adam M.
Partner: UNT Libraries Government Documents Department
open access

Single-Mode VISAR

Description: High energy-density physics (HEDP) experiments examine the properties of materials under extreme conditions. These experiments rely on the measurement of one or two velocities. These velocities are used to obtain Hugoniot relationships and thermodynamic equations of state. This methodology is referred to as 'velocimetry' and an instrument used to measure the shock wave is called a 'velocimeter' or a '(velocity) diagnostic'. The two most-widely used existing velocity diagnostics are; photonic Do… more
Date: November 16, 2007
Creator: Krauter, K
Partner: UNT Libraries Government Documents Department
open access

A Search for B+ to K+ Nu Anti-Nu

Description: A search for the rare, flavour-changing neutral current decay B{sup +} {yields} K{sup +} {nu}{bar {nu}} is presented using 81.9 fb{sup -1} of data collected at the {Upsilon}(4S) resonance by the BABAR experiment. Signal candidate events are selected through the identification of a high momentum charged kaon and significant missing energy, where the companion B{sup -} in the event has decayed semileptonically via B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}} X and X is kinematically constrain… more
Date: January 16, 2008
Creator: Jackson, Paul D.
Partner: UNT Libraries Government Documents Department
open access

Measurement of Cabibbo-Suppressed Tau Lepton Decays and the Determination of |Vus|

Description: This work presents simultaneous branching fraction measurements of the decay modes {tau}{sup -} {yields} K{sup -} n{pi}{sup 0}{nu}{sub {tau}} with n = 0,1,2,3 and {tau}{sup -} {yields} {pi}{sup -} n{pi}{sup 0}{nu}{sub {tau}} with n = 3,4. The analysis is based on a data sample of 427 x 10{sup 6} {tau}{sup +}{tau}{sup -} pairs recorded with the BABAR detector, which corresponds to an integrated luminosity of 464.4 fb{sup -1}. The measured values are {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub … more
Date: December 16, 2008
Creator: Schenk, Stefan
Partner: UNT Libraries Government Documents Department
open access

Experimental and Numerical Investigation of the Role of Initial Condition of the Dynamics of Rayleigh-Taylor Mixing

Description: Experiments and direct numerical simulations have been performed to examine the effects of initial conditions on the dynamics of a Rayleigh-Taylor mixing layer. Experiments were performed on a water channel facility to quantify the interfacial and velocity perturbations initially present at the two-fluid interface in a small Atwood number mixing layer. The measurements have been parameterized for implementation in numerical simulations of the experiment, and two- and three-dimensional direct nu… more
Date: August 16, 2004
Creator: Mueschke, N
Partner: UNT Libraries Government Documents Department
open access

Virtual tool mark generation for efficient striation analysis in forensic science

Description: In 2009, a National Academy of Sciences report called for investigation into the scienti#12;c basis behind tool mark comparisons (National Academy of Sciences, 2009). Answering this call, Chumbley et al. (2010) attempted to prove or disprove the hypothesis that tool marks are unique to a single tool. They developed a statistical algorithm that could, in most cases, discern matching and non-matching tool marks made at di#11;erent angles by sequentially numbered screwdriver tips. Moreover, in the… more
Date: November 16, 2012
Creator: Ekstrand, Laura
Partner: UNT Libraries Government Documents Department
open access

Measurement of CP Violation in B Anti-B Mixing on the Recoil of Partially Reconstructed Anti-B0 to D* L- Anti-Nu/L Using Kaon Tags

Description: After its formulation in 1960's the Standard Model of Fundamental Interactions has gone through an impressive series of successes, begun with the discovery of neutral weak currents [1] and the experimental observations of the massive carriers of weak interactions, the W{sup {+-}} and Z{sup 0} bosons [2], [3]. High precision measurements performed at LEP and SLAC test the validity of the theory to an unprecedented level of accuracy and do not show any significant deviations with respect to the S… more
Date: November 16, 2011
Creator: Gaz, Alessandro & U., /Padua
Partner: UNT Libraries Government Documents Department
open access

Evaluating Radionuclide Air Emission Stack Sampling Systems

Description: The Pacific Northwest National Laboratory (PNNL) operates a number of research and development (R&D) facilities for the U.S. Department of Energy at the Hanford Site, Washington. These facilities are subject to Clean Air Act regulations that require sampling of radionuclide air emissions from some of these facilities. A revision to an American National Standards Institute (ANSI) standard on sampling radioactive air emissions has recently been incorporated into federal and state regulations and … more
Date: December 16, 2002
Creator: Ballinger, Marcel Y.
Partner: UNT Libraries Government Documents Department
open access

Investigation of organometallic reaction mechanisms with one and two dimensional vibrational spectroscopy

Description: One and two dimensional time-resolved vibrational spectroscopy has been used to investigate the elementary reactions of several prototypical organometallic complexes in room temperature solution. The electron transfer and ligand substitution reactions of photogenerated 17-electron organometallic radicals CpW(CO){sub 3} and CpFe(CO){sub 2} have been examined with one dimensional spectroscopy on the picosecond through microsecond time-scales, revealing the importance of caging effects and odd-ele… more
Date: December 16, 2008
Creator: Cahoon, James Francis
Partner: UNT Libraries Government Documents Department
open access

International Legal Framework for Denuclearization and Nuclear Disarmament – Present Situation and Prospects

Description: This thesis is the culminating project for my participation in the OECD NEA International School of Nuclear Law. This paper will begin by providing a historical background to current disarmament and denuclearization treaties. This paper will discuss the current legal framework based on current and historical activities related to denuclearization and nuclear disarmament. Then, it will propose paths forward for the future efforts, and describe the necessary legal considerations. Each treaty or a… more
Date: December 16, 2012
Creator: Gastelum, Zoe N.
Partner: UNT Libraries Government Documents Department
open access

Budgets and behaviors of uranium and thorium series isotopes in the Santa Monica Basin off the California Coast

Description: Samples from three time-series sediment traps deployed in the Santa Monica Basin off the California coast were analyzed to study the flux and scavenging of uranium and thorium series isotopes. Variations of uranium and thorium series isotopes fluxes in the water column were obtained by integrating these time-series deployment results. Mass and radionuclide fluxes measured from bottom sediment traps compare favorably with fluxed determined from sediment core data. This agreement suggests that th… more
Date: December 16, 1991
Creator: Yu, Lei
Partner: UNT Libraries Government Documents Department
open access

Precision Measurements of Tau Lepton Decays

Description: Using data collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, the branching fractions {Beta}({tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (8.83 {+-} 0.01 {+-} 0.13)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (0.273 {+-} 0.002 {+-} 0.009)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}}) = (0.1346 {+-} 0.0010 {+-} 0.0036)… more
Date: March 16, 2010
Creator: Nugent, Ian M.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the top quark pair production cross section in proton-antiproton collisions at a center of mass energy of 1.96 TeV, hadronic top decays with the D0 detector

Description: Of the six quarks in the standard model the top quark is by far the heaviest: 35 times more massive than its partner the bottom quark and more than 130 times heavier than the average of the other five quarks. Its correspondingly small decay width means it tends to decay before forming a bound state. Of all quarks, therefore, the top is the least affected by quark confinement, behaving almost as a free quark. Its large mass also makes the top quark a key player in the realm of the postulated Hig… more
Date: January 16, 2009
Creator: Hegeman, Jeroen Guido
Partner: UNT Libraries Government Documents Department
open access

Fabrication of Yttria stabilized zirconia thin films on poroussubstrates for fuel cell applications

Description: A process for the deposition of yttria stabilized zirconia (YSZ) films, on porous substrates, has been developed. These films have possible applications as electrolyte membranes in fuel cells. The films were deposited from colloidal suspensions through the vacuum infiltration technique. Films were deposited on both fully sintered and partially sintered substrates. A critical cracking thickness for the films was identified and strategies are presented to overcome this barrier. Green film density… more
Date: June 16, 2003
Creator: Leming, Andres
Partner: UNT Libraries Government Documents Department
open access

Toward Femtosecond X-ray Spectroscopy at the Advanced Light Source

Description: The realization of tunable, ultrashort pulse x-ray sources promises to open new venues of science and to shed new light on long-standing problems in condensed matter physics and chemistry. Fundamentally new information can now be accessed. Used in a pump-probe spectroscopy, ultrashort x-ray pulses provide a means to monitor atomic rearrangement and changes in electronic structure in condensed-matter and chemical systems on the physically-limiting time-scales of atomic motion. This opens the way… more
Date: April 16, 2004
Creator: Chong, Henry Herng Wei
Partner: UNT Libraries Government Documents Department
open access

I. Excluded Volume Effects in Ising Cluster Distributions and Nuclear Multifragmentation II. Multiple-Chance Effects in Alpha-Particle Evaporation

Description: In Part 1, geometric clusters of the Ising model are studied as possible model clusters for nuclear multifragmentation. These clusters may not be considered as non-interacting (ideal gas) due to excluded volume effect which predominantly is the artifact of the cluster's finite size. Interaction significantly complicates the use of clusters in the analysis of thermodynamic systems. Stillinger's theory is used as a basis for the analysis, which within the RFL (Reiss, Frisch, Lebowitz) fluid-of-sp… more
Date: May 16, 2005
Creator: Breus, Dimitry E.
Partner: UNT Libraries Government Documents Department
open access

Rates and progenitors of type Ia supernovae

Description: The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological… more
Date: August 16, 2004
Creator: Wood-Vasey, William Michael
Partner: UNT Libraries Government Documents Department
open access

Photon and Neutral Pi 0 production in (197)Au + (197)Au collisions at sqrt S(NN) = 130 GeV

Description: Inclusive transverse momentum spectra of photons and {pi}{sup 0}s at mid-rapidity are studied as a function of collision centrality for {sup 197}Au+ {sup 197}Au collisions at {radical}s{sub NN} = 130 GeV. Photon pair conversions have been reconstructed from charged tracks measured by the main Time Project Chamber of the STAR experiment at the RHIC heavy ion facility. The transverse momentum resolution of photons with this method is estimated to be {Delta}p{sub t}/p{sub t} = 2% at 0.125 GeV/c an… more
Date: September 16, 2002
Creator: Johnson, Ian J.
Partner: UNT Libraries Government Documents Department
open access

Studies Relating to the Structure of Aluminum Hydride

Description: The object of the work was to determine the molecular structure of AlH/ sub 3/, using the techniques of nuclear spin resonance.'' Attempts to prepare ether-free AlH/sub 3/ that were unsuccessful are described. Also it was not possible to observe the deuterium signal in AlH/sub 3/. It was possible, by the use of the proton signal of the ether in AlH/sub 3/, to obtain the nuclear spin resonance absorption curve for AlH/sub 3/ by subtracting out the contributions of the ether protons to the resona… more
Date: December 16, 1957
Creator: Nickerson, R. F.
Partner: UNT Libraries Government Documents Department
open access

Monte Carlo Calculations on Intranuclear Cascades

Description: The basic assumption of the Serber model in the description of high- energy nuclear reactions is that the interactions of incident particles with complex nuclei can be described in terms of individual particle-particle collisions within the nucleus. Calculations were performed making use of the basic assumption of the Serber model, a more realistic nuclear model, recent cross-section data, and an exact statistical sampling technique. The sampling technique has not been used previously in calcul… more
Date: May 16, 1963
Creator: Bertini, H. W.
Partner: UNT Libraries Government Documents Department
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