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Measurement of the B meson Lifetimes with the Collider Detector at Fermilab
The lifetimes of the B{sup -}, B{sup 0} and B{sub s}{sup 0} mesons are measured using partially reconstructed semileptonic decays. Following semileptonic decay processes and their charge conjugates are used for this analysis: B{sup -}/B{sup 0} {yields} {ell}{sup -}{nu}D{sup 0}X; B{sup -}/B{sup 0} {yields} {ell}{sup -}{nu}D*{sup +}X; B{sub s}{sup 0} {yields} {ell}{sup -}{nu}D{sub s}{sup +}x, where {ell}{sup -} denotes either a muon or electron. The data are collected during 2002-2004 by the 8 GeV single lepton triggers in CDF Run II at the Fermilab Tevatron Collider. Corresponding integrated luminosity is about 260 and 360 pb{sup -1} used for the B{sup -}/B{sup 0} and B{sub s}{sup 0} lifetime analyses, respectively. With the single lepton triggers, events which contain a muon or electron with a transverse momentum greater than 8 GeV/c are selected. For these lepton candidates, further lepton identification cuts are applied to improve purity of the B semileptonic decay signal. After the lepton selection, three types of charm mesons associated with the lepton candidates are reconstructed. Following exclusive decay modes are used for the charm meson reconstruction: D{sup 0} {yields} K{sup -}{pi}{sup +}; D*{sup +} {yields} D{sup 0}{pi}{sub s}{sup +}, followed by D{sup 0} {yields} K{sup -}{pi}{sup +}; D{sub s}{sup …
Date:
January 1, 2006
Creator:
Uozumi, Satoru
System:
The UNT Digital Library
Measurement of the front back asymmetry in top-antitop quark pairs produced in proton-antiproton collisions at center of mass energy = 1.96 TeV
Quarks, along with leptons and force carrying particles, are predicted by the Standard Model to be the fundamental constituents of nature. In distinction from the leptons, the quarks interact strongly through the chromodynamic force and are bound together within the hadrons. The familiar proton and neutron are bound states of the light ''up'' and ''down'' quarks. The most massive quark by far, the ''top'' quark, was discovered by the CDF and D0 experiments in March, 1995. The new quark was observed in p{bar p} collisions at 1.8 TeV at the Fermilab Tevatron. The mass of the top quark was measured to be 176 {+-} 13 GeV/c{sup 2} and the cross section 6.8{sub -2.4}{sup +3.6} pb. It is the Q = 2/3, T{sub 3} = +1/2 member of the third generation weak-isospin doublet along with the bottom quark. The top quark is the final Standard Model quark to be discovered. Along with whatever is responsible for electroweak symmetry breaking, top quark physics is considered one of the least understood sectors of the Standard Model and represents a front line of our understanding of particle physics. Currently, the only direct measurements of top quark properties come from the CDF and D0 experiments …
Date:
January 1, 2006
Creator:
Schwarz, Thomas A.
System:
The UNT Digital Library
Search for anomalous production of events with a high energy lepton and photon at the Tevatron
We present results of a search for the anomalous production of events containing a high-transverse momentum charged lepton ({ell}, either e or {mu}) and photon ({gamma}), accompanied by missing transverse energy (E{sub T}), and/or additional leptons and photons, and jets (X). We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb{sup -1}, a p{bar p} collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 {ell}{gamma}E{sub T} events versus a standard model expectation of 37.3 {+-} 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 {+-} 0.7 events (corresponding to a 2.7 {sigma} effect), is not supported by the new data. In the signature of {ell}{ell}{gamma} + X we observe 31 events versus an expectation of 23.0 {+-} 2.7 events. In this sample we find no events with an extra photon or E{sub T} and so find no events like the one ee{gamma}{gamma} E{sub T} event observed in Run I.
Date:
January 1, 2006
Creator:
Loginov, Andrey Borisovich & /Moscow, ITEP
System:
The UNT Digital Library
A search for double-charged Higgs bosons at the Tevatron
We search for the pair production of doubly charged Higgs particles followed by the lepton-flavor violating decay of each Higgs into electron-and-tau and muon-and-tau pairs using 350 pb{sup -1} of data collected by the CDF II experiment at the Fermilab Tevatron. Separate searches investigate cases where three or four final state leptons are detected, and the limits for each exclusive decay mode reflect the combined results of both searches. Assuming the H{sup {+-}{+-}}{sub L} decays exclusively into like sign electron-and-tau pairs, we set a lower limit on its mass of 114 GeV/c2 at the 95 % confidence level. In the case of exclusive muon-and-tau decays, we set a lower mass limit of 112 GeV/c2 also at the 95% confidence level.
Date:
January 1, 2006
Creator:
Baraoiant, Sasha
System:
The UNT Digital Library
Search for techniparticles at D0 Run II
Technicolor theory (TC) accomplishes the necessary electroweak symmetry breaking responsible for the mass of the elementary particles. TC postulates the existence of a new SU(N{sub TC}) gauge theory. Like QCD the exchange of gauge bosons causes the existence of a non-vanishing chiral condensate which dynamically breaks the SU(N{sub TC}){sub L} x SU(N{sub TC}){sub R} symmetry. This gives rise to N{sub TC}{sup 2}-1 Nambu-Goldstone Bosons. Three of these Goldstone Bosons become the longitudinal components of the W{sup {+-}} and Z which therefore acquire mass; the remaining ones are new particles (technihadrons) that can be produced at the high energy colliders and detected. The Technicolor Straw Man Model (TCSM) is a version of the dynamical symmetry breaking with a large number of technifermions and a relative low value of their masses. One of the processes predicted by the TCSM is q{bar q} {yields} V{sub T} {yields} W{pi}{sub T}, where V{sub T} is the Technicolor equivalent of the QCD vector meson and {pi}{sub T} is the equivalent of the pion. W is the electroweak gauge boson of the Standard Model. This dissertation describes the search for W{pi}{sub T} with the D0 detector, a multi-purpose particle detector located at one of the collision points …
Date:
January 1, 2006
Creator:
Feligioni, Lorenzo & U., /Boston
System:
The UNT Digital Library
Search for the single top quarks produced in s-channel via electroweak interactions at s = 1-96 at the Tevatron
The authors present a search for single top quarks produced in the s-channel electroweak production mode. The search is performed in the electron+jets decay channels, with one or more secondary-vertex tagged jets to indicate the presence of a b-jet and hence improving the signal:background ratio. Separation between signal and background is further enhanced by the use of Feed Forward Neural networks. 360 pb{sup -1} of Run II data used for this analysis was delivered by the Tevatron, and collected by D0 between August 2002 and August 2004. The resulting 95% confidence level upper limit is 4 pb.
Date:
January 1, 2006
Creator:
Jabeen, Shabnam
System:
The UNT Digital Library
Secure execution environments through reconfigurable lightweight cryptographic components
This doctoral dissertation discusses secure execution environments through reconfigurable lightweight cryptographic components. The author considers the four most important dimensions of software protection.
Date:
2006
Creator:
Gomathisankaran, Mahadevan
System:
The UNT Digital Library
Multipole Analysis of Circular Cylindircal Magnetic Systems
This thesis deals with an alternate method for computing the external magnetic field from a circular cylindrical magnetic source. The primary objective is to characterize the magnetic source in terms of its equivalent multipole distribution. This multipole distribution must be valid at points close to the cylindrical source and a spherical multipole expansion is ill-equipped to handle this problem; therefore a new method must be introduced. This method, based upon the free-space Green's function in cylindrical coordinates, is developed as an alternative to the more familiar spherical harmonic expansion. A family of special functions, called the toroidal functions or Q-functions, are found to exhibit the necessary properties for analyzing circular cylindrical geometries. In particular, the toroidal function of zeroth order, which comes from the integral formulation of the free-space Green's function in cylindrical coordinates, is employed to handle magnetic sources which exhibit circular cylindrical symmetry. The toroidal functions, also called Q-functions, are the weighting coefficients in a ''Fourier series-like'' expansion which represents the free-space Green's function. It is also called a toroidal expansion. This expansion can be directly employed in electrostatic, magnetostatic, and electrodynamic problems which exhibit cylindrical symmetry. Also, it is shown that they can be used as an …
Date:
January 9, 2006
Creator:
Selvaggi, J
System:
The UNT Digital Library
The Synthesis, Characterization and Catalytic Reaction Studies ofMonodisperse Platinum Nanoparticles in Mesoporous Oxide Materials
None
Date:
January 15, 2006
Creator:
Rioux, Robert M.
System:
The UNT Digital Library
CPT conservation and atmospheric neutrinos in the MINOS far detector
The MINOS Far Detector is a 5400 ton iron calorimeter located at the Soudan state park in Soudan Minnesota. The MINOS far detector can observe atmospheric neutrinos and separate charge current {nu}{sub {mu}} and {bar {nu}}{sub {mu}} interactions by using a 1.4 T magnetic field to identify the charge of the produced muon. The CPT theorem requires that neutrinos and anti-neutrinos oscillate in the same way. In a fiducial exposure of 5.0 kilo-ton years a total of 41 candidate neutrino events are observed with an expectation of 53.1 {+-} 7.6(system.) {+-} 7.2(stat.) unoscillated events or 31.6 {+-} 4.7(system.) {+-} 5.6(stat.) events with {Delta}m{sup 2} = 2.4 x 10{sup -3} eV{sup 2}, sin{sup 2}(2{theta}) = 1.0 as oscillation parameters. These include 28 events which can have there charge identified with high confidence. These 28 events consist of 18 events consistent with being produced by {nu}{sub {mu}} and 10 events being consistent with being produced by {bar {nu}}{sub {mu}}. No evidence of CPT violation is observed.
Date:
February 1, 2006
Creator:
Becker, Bernard Raymond
System:
The UNT Digital Library
Identification of electrons in the forward region of the CDF experiment for the search for electroweak top quark production
None
Date:
February 1, 2006
Creator:
Kemp, Yves
System:
The UNT Digital Library
Measuring the branching ratio of the rare decay pi0 --> e+ e-
A precise branching ratio measurement of the rare decay {pi}{sup 0} {yields} e{sup +}e{sup -} has been made. The measurement was made with the rare kaon decay experiment KTeV at Fermilab where the source of {pi}{sup 0}s was K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0} decaying in flight. A total of 794 fully reconstructed K{sub L} {yields} 3{pi}{sup 0} events consistent with two of the intermediate {pi}{sup 0}s decaying into {gamma}{gamma} and one into e{sup +}e{sup -} were collected. An estimated 53.2 {+-} 11.0 of these events were expected to be background. Normalizing to the {pi}{sup 0} Dalitz decay they found Br({pi}{sup 0} {yields} e{sup +}e{sup -}, (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2} > 0.95) = (6.44 {+-} 0.25(stat) {+-} 0.22(syst)) x 10{sup -8} where internal radiation, {pi}{sup 0} {yields} e{sup +}e{sup -}({gamma}), was limited by the requirement (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2} > 0.95 which separated it from the tree level Dalitz decay, {pi}{sup 0} {yields} e{sup +}e{sup -}P{gamma}.
Date:
February 1, 2006
Creator:
Niclasen, Rune
System:
The UNT Digital Library
Two-axis Beam Steering Mirror Control system for Precision Pointing and Tracking Applications
Precision pointing and tracking of laser beams is critical in numerous military and industrial applications. This is particularly true for systems requiring atmospheric beam propagation. Such systems are plagued by environmental influences which cause the optical signal to break up and wander. Example applications include laser communications, precision targeting, active imaging, chemical remote sensing, and laser vibrometry. The goal of this project is to build a beam steering system using a two-axis mirror to maintain precise pointing control. Ultimately, position control to 0.08% accuracy (40 {micro}rad) with a bandwidth of 200 Hz is desired. The work described encompasses evaluation of the instrumentation system and the subsequent design and implementation of an analog electronic controller for a two-axis mirror used to steer the beam. The controller operates over a wide temperature range, through multiple mirror resonances, and is independent of specific mirrors. The design was built and successfully fielded in a Lawrence Livermore National Laboratory free-space optics experiment. All measurements and performance parameters are derived from measurements made on actual hardware that was built and field tested. In some cases, specific design details have been omitted that involve proprietary information pertaining to Lawrence Livermore National Laboratory patent positions and claims. These …
Date:
February 8, 2006
Creator:
Ulander, K
System:
The UNT Digital Library
Sum-Frequency Generation from Chiral Media and Interfaces
Sum frequency generation (SFG), a second-order nonlinear optical process, is electric-dipole forbidden in systems with inversion symmetry. As a result, it has been used to study chiral media and interfaces, systems intrinsically lacking inversion symmetry. This thesis describes recent progresses in the applications of and new insights into SFG from chiral media and interfaces. SFG from solutions of chiral amino acids is investigated, and a theoretical model explaining the origin and the strength of the chiral signal in electronic-resonance SFG spectroscopy is discussed. An interference scheme that allows us to distinguish enantiomers by measuring both the magnitude and the phase of the chiral SFG response is described, as well as a chiral SFG microscope producing chirality-sensitive images with sub-micron resolution. Exploiting atomic and molecular parity nonconservation, the SFG process is also used to solve the Ozma problems. Sum frequency vibrational spectroscopy is used to obtain the adsorption behavior of leucine molecules at air-water interfaces. With poly(tetrafluoroethylene) as a model system, we extend the application of this surface-sensitive vibrational spectroscopy to fluorine-containing polymers.
Date:
February 13, 2006
Creator:
Ji, Na
System:
The UNT Digital Library
An Experimental Investigation of the Structural Wave Scattering Due to Impedance Discontinuities on a Cylindrical Structure
Experimental, numerical, and analytical work has shown that the response of a shell to a distributed force wave possesses unique characteristics which are dependent on the nature of structure attached to the shell. Specific characteristics which influence the response are the distribution of the discontinuities around the circumference (periodic/aperiodic), the impedance of the discontinuities relative to that of the shell, and the type of impedance (mass or stiffness). Traditional shell theory predicts low frequency, radial-dominated structural mode shapes of a shell with a sinusoidal distribution of displacement amplitudes. Due to the orthogonal nature of these mode shapes, the response of the structure to a traveling radial force wave with sinusoidal content at a given harmonic is due solely to the response of the mode shape with harmonic content of the same order. Introduction of impedance discontinuities to a shell yield complex mode shapes, which may be characterized by the summation of several harmonic components. These modes are no longer orthogonal in the presence of discontinuities, yielding harmonic content across various modal orders. As a result, a purely sinusoidal forcing function can excite several modes of the structure. Structural scattering as discussed in this paper refers to the phenomena in which …
Date:
February 15, 2006
Creator:
Glotzbecker, RJ
System:
The UNT Digital Library
Multispectral Thermal Imagery and Its Application to the Geologic Mapping of the Koobi Fora Formation, Northwestern Kenya
None
Date:
February 15, 2006
Creator:
Green, Mary K.
System:
The UNT Digital Library
The Sorption/Desorption Behavior of Uranium in Transport Studies Using Yucca Mountain Alluvium
Yucca Mountain, Nevada is the proposed site of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste in the United States. In the event repository engineered barriers fail, the saturated alluvium located south of Yucca Mountain is expected to serve as a natural barrier to the migration of radionuclides to the accessible environment. The purpose of this study is to improve the characterization of uranium retardation in the saturated zone at Yucca Mountain to support refinement of an assessment model. The distribution of uranium desorption rates from alluvium obtained from Nye County bore holes EWDP-19IM1, EWDP-10SA, EWDP-22SA were studied to address inconsistencies between results from batch sorption and column transport experiments. The alluvium and groundwater were characterized to better understand the underlying mechanisms of the observed behavior. Desorption rate constants were obtained using an activity based mass balance equation and column desorption experiments were analyzed using a mathematical model utilizing multiple sorption sites with different first-order forward and reverse reaction rates. The uranium desorption rate constants decreased over time, suggesting that the alluvium has multiple types of active sorption sites with different affinities for uranium. While a significant fraction of the initially sorbed uranium desorbed …
Date:
February 15, 2006
Creator:
Scism, C. D.
System:
The UNT Digital Library
Ultrasonic Digital Communication System for a Steel Wall Multipath Channel: Methods and Results
As of the development of this thesis, no commercially available products have been identified for the digital communication of instrumented data across a thick ({approx} 6 n.) steel wall using ultrasound. The specific goal of the current research is to investigate the application of methods for digital communication of instrumented data (i.e., temperature, voltage, etc.) across the wall of a steel pressure vessel. The acoustic transmission of data using ultrasonic transducers prevents the need to breach the wall of such a pressure vessel which could ultimately affect its safety or lifespan, or void the homogeneity of an experiment under test. Actual digital communication paradigms are introduced and implemented for the successful dissemination of data across such a wall utilizing solely an acoustic ultrasonic link. The first, dubbed the ''single-hop'' configuration, can communicate bursts of digital data one-way across the wall using the Differential Binary Phase-Shift Keying (DBPSK) modulation technique as fast as 500 bps. The second, dubbed the ''double-hop'' configuration, transmits a carrier into the vessel, modulates it, and retransmits it externally. Using a pulsed carrier with Pulse Amplitude Modulation (PAM), this technique can communicate digital data as fast as 500 bps. Using a CW carrier, Least Mean-Squared (LMS) adaptive …
Date:
February 16, 2006
Creator:
Murphy, TL
System:
The UNT Digital Library
Measurement of b-quark Jet Shapes at CDF
The main topic of this thesis is the measurement of b-quark jet shapes at CDF. CDF is an experiment located at Fermilab, in the United States, which studies proton-antiproton collisions at a center of mass energy of 1.96TeV. To reach this energy, the particles are accelerated using the Tevatron accelerator which is currently the highest energy collider in operation. The data used for this analysis were taken between February 2002 and September 2004 and represent an integrated luminosity of about 300 pb{sup -1}. This is the first time that b-quark jet shapes have been measured at hadron colliders. The basis of this measurement lies in the possibility of enhancing the b-quark jet content of jet samples by requiring the jets to be identified as having a displaced vertex inside the jet cone. Such jets are called tagged. This enhances the b-quark jet fraction from about 5% before tagging to 20-40% after tagging, depending on the transverse momentum of the jets. I verified that it is possible to apply this secondary vertex tagging algorithm to different cone jet algorithms (MidPoint and JetClu) and different cone sizes (0.4 and 0.7). I found that the performance of the algorithm does not change significantly, …
Date:
March 1, 2006
Creator:
Lister, Alison
System:
The UNT Digital Library
Measurement of J/psi meson and b-hadron production cross section at sqrt(s) = 1.96 TeV
A new measurement of the inclusive and differential production cross sections of J/{psi} mesons and b-hadrons in proton-antiproton collisions at {radical}s = 1960 GeV is presented. The data correspond to an integrated luminosity of 39.7 pb{sup -1} collected by the CDF Run II detector. The integrated cross section for inclusive J/{psi} production for all transverse momenta from 0 to 20 GeV/c in the rapidity range |y| < 0.6 is found to be 4.08 {+-} 0.02(stat){sub -0.33}{sup +0.36}(syst) {mu}b. The fraction of J/{psi} events from the decay of the long-lived b-hadrons is separated by using the lifetime distribution in all events with p{sub T}(J/{psi}) > 1.25 GeV/c. The total cross section for b-hadrons, including both hadrons and anti-hadrons, decaying to J/{psi} with transverse momenta greater than 1.25 GeV/c in the rapidity range |y(J/{psi})| < 0.6, is found to be 0.330 {+-} 0.005(stat){sub -0.033}{sup +0.036}(syst) {mu}b. Using a Monte Carlo simulation of the decay kinematics of b-hadrons to all final states containing a J/{psi}, the first measurement of the total single b-hadron cross section down to zero transverse momentum is extracted at sqrts = 1960 GeV. The total single b-hadron cross section integrated over all transverse momenta for b-hadrons in the rapidity …
Date:
March 1, 2006
Creator:
Yamashita, Tomohiro & U., /Okayama
System:
The UNT Digital Library
Measurement of the strange - antistrange asymmetry at NLO in QCD from NuTeV dimuon data
A measurement of the asymmetry between the strange and antistrange quark distributions, from a next to leading order QCD analysis of dimuon events measured by the NuTeV experiment at Fermilab is presented. Neutrino charged current events with two muons in the final state provide a direct means for studying charm production and measuring the strange sea. NuTeV's sign selected beam allows independent measurement of the strange and antistrange seas. An improved measurement of the neutrino and antineutrino forward dimuon cross section tables, using the complete charged current event sample for normalization is performed. These tables are then analyzed at NLO to measure the strange and antistrange seas. Detector acceptance is modeled using an NLO charm cross section differential in all variables required. The strange quark distribution is found to have an integrated momentum weighted asymmetry of +0.00196 {+-} 0.00046(stat) {+-} 0.00045(syst) {+-} 0.00182(external). The charm mass is found to be 1.41 {+-} 0.10(stat) {+-} 0.08(syst) {+-} 0.12(external) GeV.
Date:
March 1, 2006
Creator:
Mason, David Alexander & U., /Oregon
System:
The UNT Digital Library
Measurement of the Top Quark Pair Production Cross Section in p anti-p collisions at s**(1/2) = 1.96 TeV
None
Date:
March 1, 2006
Creator:
Otero y Garzon, Gustavo J.
System:
The UNT Digital Library
Pipeline Structural Health Monitoring Using Macro-fiber Composite Active Sensors
The United States economy is heavily dependent upon a vast network of pipeline systems to transport and distribute the nation's energy resources. As this network of pipelines continues to age, monitoring and maintaining its structural integrity remains essential to the nation's energy interests. Numerous pipeline accidents over the past several years have resulted in hundreds of fatalities and billions of dollars in property damages. These accidents show that the current monitoring methods are not sufficient and leave a considerable margin for improvement. To avoid such catastrophes, more thorough methods are needed. As a solution, the research of this thesis proposes a structural health monitoring (SHM) system for pipeline networks. By implementing a SHM system with pipelines, their structural integrity can be continuously monitored, reducing the overall risks and costs associated with current methods. The proposed SHM system relies upon the deployment of macro-fiber composite (MFC) patches for the sensor array. Because MFC patches are flexible and resilient, they can be permanently mounted to the curved surface of a pipeline's main body. From this location, the MFC patches are used to monitor the structural integrity of the entire pipeline. Two damage detection techniques, guided wave and impedance methods, were implemented as …
Date:
March 1, 2006
Creator:
Thien, Andrew B.
System:
The UNT Digital Library
Cultural Hybridity: Arab/Latino -- A Reflexive Approach
Thesis written by a student in the UNT Honors College discussing the experiences of being multi-ethnic and multicultural, focusing on people with a Latino and Arabic background.
Date:
Spring 2006
Creator:
Rios, L. Danyel
System:
The UNT Digital Library