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Development and Performance of Detectors for the Cryogenic Dark Matter Search Experiment with an Increased Sensitivity Based on a Maximum Likelihood Analysis of Beta Contamination

Description: The Cryogenic Dark Matter Search (CDMS) uses cryogenically-cooled detectors made of germanium and silicon in an attempt to detect dark matter in the form of Weakly-Interacting Massive Particles (WIMPs). The expected interaction rate of these particles is on the order of 1/kg/day, far below the 200/kg/day expected rate of background interactions after passive shielding and an active cosmic ray muon veto. Our detectors are instrumented to make a simultaneous measurement of both the ionization ene… more
Date: January 1, 2004
Creator: Driscoll, Donald D. & U., /Case Western Reserve
Partner: UNT Libraries Government Documents Department
open access

Measurement of the $B \to J/\psi X$ inclusive cross-section at the collider detector at Fermilab

Description: The Collider Detector at Fermilab (CDF) is a multi-purpose detector designed to study proton-antiproton collisions at center-of-mass energies of 1.96 TeV/c{sup 2}. One of the most importatn components of CDF is the silicon tracking detector. A detailed description of the testing and construction of the CDF silicon tracker is presented. Measurements of the tracking efficiency of the completed detector are also provided. Using 36 pb{sup -1} of the J/{psi} data sample collected by CDF between Febr… more
Date: January 1, 2004
Creator: Waschke, Simon
Partner: UNT Libraries Government Documents Department
open access

A Measurement of the Bs Lifetime at CDF Run II

Description: This thesis describes a measurement of the proper lifetime of the B{sub s}{sup 0} mesons produced in proton-antiproton collisions at a center of mass energy of 1.96 TeV, collected by the CDF experiment at Fermilab. The B{sub s}{sup 0} meson lifetime is measured in its semileptonic decay mode, B{sub s}{sup 0} {yields} {ell}{sup +}{nu}{sub {ell}}D{sub s}{sup -}. The D{sub s}{sup -} meson candidates are reconstructed in the decay mode D{sub s}{sup -} {yields} {phi}{pi}, with {phi} {yields} K{sup +… more
Date: January 1, 2004
Creator: Farrington, Sinead
Partner: UNT Libraries Government Documents Department
open access

Search for chargino-neutralino pair production with the D0 detector at the Tevatron

Description: We have searched for evidence for the chargino {bar {chi}}{sub 1}{sup {+-}} and neutralino ({bar {chi}}{sub 2}{sup 0}) pair production in proton anti-proton collisions at a center of mass energy of 1.96 TeV with the D0 detector at the Fermilab Tevatron Collider. Data corresponding to an integrated luminosity of 124.5 pb{sup -1} were examined for events containing like-sign electron pair and missing energy for the first time at D0. They observed no excess above the yield from Standard Model proc… more
Date: January 1, 2004
Creator: Wang, Zhongmin
Partner: UNT Libraries Government Documents Department
open access

Search for doubly-charged Higgs Boson production in the decay H++ H-- ---> mu+ mu+ mu- mu - with the D0 detector at s**(1/2) = 1.96-TeV

Description: This work presents a search for the pair production of doubly-charged Higgs Bosons in the process p{bar p} {yields} H{sup ++}H{sup --} {yields} {mu}{sup +}{mu}{sup +}{mu}{sup -}{mu}{sup -} using inclusive dimuon events. These data correspond to an integrated luminosity of about 113 pb 1 and were recorded by the D0 experiment between August 2002 and June 2003. In the absence of a signal, 95% confidence level mass limits of M(H{sub L}{sup {+-}{+-}}) > 118.6 GeV/c{sup 2} and M(H{sub R}{sup {+-}… more
Date: January 1, 2004
Creator: Zdrazil, Marian
Partner: UNT Libraries Government Documents Department
open access

Tests of Enhanced Leading Order QCD in W Boson plus Jet Production in 1.96-TeV Proton-Antiproton Collisions

Description: The authors have studied the W + {ge} n jets process in Tevatron Run II experiment. The data used correspond to a total integrated luminosity of 72 pb{sup -1} taken from March 2002 through January 2003. The lowest order QCD predictions have been tested with a new prescription of the parton-jet matching, which allows to construct the enhanced LO phase space. According to this procedure, one gets unique results which do not depend on unphysical bias of kinematical cuts to avoid the collinear/infr… more
Date: January 1, 2004
Creator: Tsuno, Soushi
Partner: UNT Libraries Government Documents Department
open access

Sum frequency generation (SFQ) vibrational spectroscopy studies of combustion reactions on platinum single crystal surfaces

Description: We have studied the dissociation of CO catalyzed by platinum single crystals. At 40 torr of CO, the Pt(111) crystal dissociates CO at 673 K. Under the same conditions, Pt(100) dissociates CO at 500 K, and Pt(557) dissociates CO at 548 K. Hence, the CO dissociation reaction is a structure sensitive reaction. SFG was used to monitor the CO top site resonance as the platinum crystals were heated to the dissociation temperature when exposed to 40 torr of CO. In all three systems, the CO resonance s… more
Date: January 15, 2004
Creator: Gaughan, Jessica S.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the B+- Lifetime and Top Quark Identification Using Secondary Vertex B-Tagging

Description: This dissertation presents a preliminary measurement of the B{sup {+-}} lifetime through the full reconstruction of its decay chain, and the identification of top quark production in the electron plus jets channel using the displaced vertex b-tagging method. Its main contribution is the development, implementation and optimization of the Kalman filter algorithm for vertex reconstruction, and of the displaced vertex technique for tagging jets arising from b quark fragmentation, both of which hav… more
Date: February 1, 2004
Creator: Schwartzman, Ariel G. & U., /Buenos Aires
Partner: UNT Libraries Government Documents Department
open access

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: The direct observation of the top quark was first achieved at the Tevatron proton anti-proton collider at Fermilab. This discovery completed the third generation quark sector where the top quark is expected to accompany the bottom quark in the weak isospin doublet. This dissertation discusses the experimental verification of the production cross section as predicted by the Standard Model. A measurement of the t{bar t} production cross section using 107.9 pb{sup -1} of p{bar p} collisions at {ra… more
Date: February 1, 2004
Creator: Ray, Heather Lynn
Partner: UNT Libraries Government Documents Department
open access

A measurement of the t anti-t production cross-section in proton anti-proton collisions at s**(1/2) = 1.96-TeV with the D0 detector at the Tevatron using final states with a muon and jets

Description: A preliminary measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV is presented. The {mu}-plus-jets final state is analyzed in a data sample of 94 pb{sup -1} and a total of 14 events are selected with a background expectation of 11.7 {+-} 1.9 events. The measurement yields: {sigma}{sub p{bar p} {yields} t{bar t} + X} = 2.4{sub -3.5}{sup +4.2}(stat.){sub -2.6}{sup +2.5}(syst.) {+-} 0.3(lumi.) pb. The analysis, being part of a larger effort to re-observe the top quark in … more
Date: February 1, 2004
Creator: Klute, Markus
Partner: UNT Libraries Government Documents Department
open access

The neutron electric form factor to Q² = 1.45 (GeV/c)²

Description: The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within … more
Date: February 1, 2004
Creator: Plaster, Bradley
Partner: UNT Libraries Government Documents Department
open access

Mass spectrum analysis of K- pi+ from the semileptonic decay D+ --> K- pi+ mu+ nu

Description: The Higgs mechanism preserves the gauge symmetries of the Standard Model while giving masses to the W, Z bosons. Supersymmetry, which protects the Higgs boson mass scale from quantum corrections, predicts at least 5 Higgs bosons, none of which has been directly observed. This thesis presents a search for neutral Higgs bosons, produced in association with bottom quarks. The production rate is greatly enhanced at large values of the Supersymmetric parameter tan {beta}. High-energy p{bar p} collis… more
Date: March 1, 2004
Creator: Massafferri Rodrigues, Andre & /Rio de Janeiro, CBPF
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Ratio of Branching Fractions Br(Bs -> Ds- pi+)/Br(B -> D- pi+) at CDF-II

Description: The measurement of B{sub s}{sup 0} mixing is one of the flagship analyses for the Run II B physics program. The sensitivity of the measurement to the frequency of B{sub s}{sup 0} oscillations strongly depends on the number of reconstructed B{sub s}{sup 0} mesons. They present the measurement of the ratio of branching fractions Br(B{sub s}{sup 0} {yields} D{sub s}{sup -}{pi}{sup +})/Br(B{sup 0} {yields} D{sup -}{pi}{sup +}), which directly influences the number of B{sub s}{sup 0} events availabl… more
Date: March 1, 2004
Creator: Furic, Ivan Kresimir
Partner: UNT Libraries Government Documents Department
open access

p{sup 0} Meson Photoproduction using Linearly Polarized Photons with the CLAS detector

Description: The work presented in this thesis describes the first experimental measurement of the photon asymmetry of the exclusive {rvec {gamma}} {yields} {rho}{sup 0}p {yields} {pi}{sup +}{pi}{sup -}p reaction. The data were gathered during the summer of 2001 as a proof of principle study using a polarized beam of photons with the CLAS detector in Hall B of Jefferson Lab for the first time. The aim of the g8a set of experiments is to improve the understanding of the underlying symmetry of the quark degre… more
Date: March 1, 2004
Creator: Gordon, Chris
Partner: UNT Libraries Government Documents Department
open access

Search for first-generation leptoquarks in the jets and missing transverse energy topology in proton-antiproton collisions at center-of-mass energy 1.96 TeV

Description: The authors performed a search for the pair production of first-generation leptoquarks using 191 pb{sup -1} of proton-antiproton collision data recorded by the CDF experiment during Run II of the Tevatron. The leptoquarks are sought via their decay into a neutrino and quark, which yields missing transverse energy and several high-E{sub T} jets. Several control regions were studied to check the background estimation from Standard Model sources, with good agreement observed in data. In the leptoq… more
Date: March 1, 2004
Creator: Tsybychev, Dmitri
Partner: UNT Libraries Government Documents Department
open access

Search for New Physics in Dielectron Events in 1.96-TeV Proton - Anti-proton Collisions

Description: The authors have searched for new physics beyond the Standard Model of elementary particle physics in dielectron decay mode at the CDF (Collider Detector at Fermilab) experiment in {bar p}p collisions at {radical}s = 1.96 TeV. The data were collected during the 2002-2003 runs corresponding to an integrated luminosity of 200 pb{sup -1}. Many extensions of the Standard Model have been proposed. Grand Unified Theories (GUT) assumes a larger gauge symmetry group and predict new gauge bosons. GUT ha… more
Date: March 1, 2004
Creator: Ikado, Koji & U., /Waseda
Partner: UNT Libraries Government Documents Department
open access

Spatially indirect excitons in coupled quantum wells

Description: Microscopic quantum phenomena such as interference or phase coherence between different quantum states are rarely manifest in macroscopic systems due to a lack of significant correlation between different states. An exciton system is one candidate for observation of possible quantum collective effects. In the dilute limit, excitons in semiconductors behave as bosons and are expected to undergo Bose-Einstein condensation (BEC) at a temperature several orders of magnitude higher than for atomic B… more
Date: March 1, 2004
Creator: Lai, Chih-Wei Eddy
Partner: UNT Libraries Government Documents Department
open access

Bio-Aerosol Detection Using Mass Spectrometry: Public Health Applications

Description: I recently spent a summer as an intern at the Lawrence Livermore National Laboratory. I worked on a project involving the real-time, reagentless, single cell detection of aerosolized pathogens using a novel mass spectrometry approach called Bio-Aerosol Mass Spectrometry (BAMS). Based upon preliminary results showing the differentiation capabilities of BAMS, I would like to explore the development and use of this novel detection system in the context of both environmental and clinical sample pat… more
Date: March 5, 2004
Creator: Ludvigson, L D
Partner: UNT Libraries Government Documents Department
open access

Laser Ion Acceleration from the Interaction of Ultra-Intense laser Pulse with thi foils

Description: The discovery that ultra-intense laser pulses (I > 10{sup 18} W/cm{sup 2}) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface … more
Date: March 12, 2004
Creator: Allen, M
Partner: UNT Libraries Government Documents Department
open access

Automatic MEA Coupling Tester: two proposed designs

Description: Thesis written by a student in the UNT Honors College discussing the development of an automatic coupling tester to test for electrode-electrode coupling on an Malt Extract Agar plate.
Date: Spring 2004
Creator: Jain, Vivek
Partner: UNT Honors College
open access

Characterization of Functionalized Self-Assembled Monolayers and Surface-Attached Interlocking Molecules Using Near-Edge X-ray Absorption Fine Structure Spectroscopy

Description: Quantitative knowledge of the fundamental structure and substrate binding, as well as the direct measurement of conformational changes, are essential to the development of self-assembled monolayers (SAMs) and surface-attached interlocking molecules, catenanes and rotaxanes. These monolayers are vital to development of nano-mechanical, molecular electronic, and biological/chemical sensor applications. This dissertation investigates properties of functionalized SAMs in sulfur-gold based adsorbed … more
Date: March 24, 2004
Creator: Willey, T & Willey, T
Partner: UNT Libraries Government Documents Department
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