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Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector

Description: We present the search for the lepton flavour violating decay {tau} {yields} lK{sup 0}{sub s} with the BaBar experiment data. This process and many other lepton flavour violating {tau} decays, like {tau} {yields} {mu}{gamma} and {tau} {yields} lll, are one of the most promising channel to search for evidence of new physics. According to the Standard Model and the neutrino mixing parameters, branching fractions are estimated well below 10{sup -14}, but many models of new physics allow for branchi… more
Date: March 20, 2009
Creator: Cenci, Riccardo
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

Simulation free measurement of the B+ lifetime using decays selected using displaced tracks

Description: The lifetime of the B{sup {+-}} meson is measured using the decay channel B{sup +} {yields} {bar D}{sup 0}{pi}{sup +}. The measurement is made using approximately 1.0 fb{sup -1} of Tevatron proton-anti-proton collision data at {radical}s = 1.96 TeV collected by the CDF detector. The data were collected using impact parameter based triggers that were designed to select events with a secondary vertex. The trigger selection criteria result in data rich in a variety of B hadron decays, but intrinsi… more
Date: March 1, 2009
Creator: Malde, Sneha
Partner: UNT Libraries Government Documents Department
open access

The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems

Description: In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an e… more
Date: March 20, 2009
Creator: Guo, Jiquan
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Oscillation Frequency of B_s Mesons in the Hadronic Decay Mode B_s-> pi D_s(phi pi)X$ with the D0 Detector at the Fermilab Tevatron Collider

Description: The standard model (SM) of particle physics is a theory, describing three out of four fundamental forces. In this model the Cabibbo-Kobayashi-Maskawa (CKM) matrix describes the transformation between the mass and weak eigenstates of quarks. The matrix properties can be visualized as triangles in the complex plane. A precise measurement of all triangle parameters can be used to verify the validity of the SM. The least precisely measured parameter of the triangle is related to the CKM element |V{… more
Date: March 1, 2009
Creator: Weber, Gernot August & /Mainz U., Inst. Phys.
Partner: UNT Libraries Government Documents Department
open access

Neutrino and antineutrino inclusive charged-current cross section measurement with the MINOS near detector

Description: This thesis presents the measurement of energy dependence of the neutrino-nucleon inclusive charged current cross section on an isoscalar target in the range 3-50 GeV for neutrinos and 5-50 GeV energy range for antineutrinos. The data set was collected with the MINOS Near Detector using the wide band NuMI beam at Fermilab. The size of the charged current sample is 1.94 x 10{sup 6} neutrino events and 1.60 x 10{sup 5} antineutrino events. The flux has been extracted using a low hadronic energy s… more
Date: March 1, 2009
Creator: Bhattacharya, Debdatta & U., /Pittsburgh
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Single Top Quark Production Cross Section in 1.96-TeV Proton-Antiproton Collisions

Description: Top quarks are predominantly produced in pairs via the strong interaction in {bar p}p collisions at {radical}s = 1.96 TeV . The top quark has a weak isospin 1/2, composing a weak isospin doublet with the bottom quark. This characteristic predicts not only top quark pair production via strong interaction but also single production together with a bottom quark via weak interaction. However, finding single top quark production is challenging since it is rarely produced ({sigma}{sub singletop} = 2.… more
Date: March 1, 2009
Creator: Nakamura, Koji
Partner: UNT Libraries Government Documents Department
open access

Measurement of the $WW+WZ$ production cross section in a semileptonic decay mode at CDF

Description: The measurement of the WW + WZ production cross section in a semileptonic decay mode is presented. The measurement is carried out with 4.6 fb{sup -1} of integrated luminosity collected by the CDF II detector in {radical}s = 1.96 TeV proton-antiproton collisions at the Tevatron. The main experimental challenge is identifying the signal in the overwhelming background from W+jets production. The modeling of the W+jets background is carefully studied and a matrix element technique is used to build … more
Date: March 1, 2010
Creator: Hurwitz, Martina
Partner: UNT Libraries Government Documents Department
open access

Rhodium mediated bond activation: from synthesis to catalysis

Description: Recently, our lab has developed monoanionic tridentate ligand, To{sup R}, showing the corresponding coordination chemistry and catalyst reactivity of magnesium, zirconium, zinc and iridium complexes. This thesis details synthetic chemistry, structural study and catalytic reactivity of the To{sup R}-supported rhodium compounds. Tl[To{sup R}] has been proved to be a superior ligand transfer agent for synthesizing rhodium complexes. The salt metathesis route of Tl[To{sup M}] with [Rh({mu}-Cl)(CO)]… more
Date: March 6, 2012
Creator: Ho, Hung-An
Partner: UNT Libraries Government Documents Department
open access

Study of the (e,e'p) quasi-elastic reaction in complex nuclei: theory and experiment

Description: Experimental coincidence cross section and transverse-longitudinal asymmetry A{sub TL} have been obtained for the quasielastic (e,e'p) reaction in {sup 16}O, {sup 12}C, and {sup 208}Pb in constant q-ω kinematics in the missing momentum range -350 < p{sub miss} < 350 MeV/c. In these experiments, performed in experimental Hall A of the Thomas Jefferson National Accelerator Facility (JLAB), the beam energy and the momentum and angle of the scattered electrons were kept fixed, while the … more
Date: March 1, 2010
Creator: Herraiz, Joaquin Lopez
Partner: UNT Libraries Government Documents Department
open access

Reconciliation

Description: The content of my work focused on examining the relationship between certain elements of nature and of human beings and was also based on the question of what true life is. The woodcut process - combined with the other printing techniques such as intaglio, collagraph, and monotype - was adopted as a potentially successful medium for conveying the content of the work. Overlay printing techniques and repeated textures were utilized as well.
Date: March 1996
Creator: Chung, Miok
Partner: UNT Libraries
open access

Recycling Culture and Media

Description: A comparison of classical and contemporary cultures was made by recreating classical sculptural imagery in contemporary recyclable materials. I proposed to use the detritus of modern culture to render sculpture that was ancient in subject, stance, and scale. The intention of this work was to create a visual discourse between cultures by bringing together elements of each, showing points of congruence and disparity.
Date: March 1995
Creator: Drew, Robert S.
Partner: UNT Libraries
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

Measurements of the top quark pair production cross section and an estimate of the D0 silicon detector lifetime

Description: This thesis presents two measurements of the top quark pair production cross section at {radical}s = 1:96 TeV using data from the D0 experiment. Both measurements are performed in the dilepton final state and make use of secondary vertex b-tagging.
Date: March 1, 2007
Creator: Strandberg, Sara & U., /Stockholm
Partner: UNT Libraries Government Documents Department
open access

Measurement of J/psi meson and b-hadron production cross section at sqrt(s) = 1.96 TeV

Description: 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.… more
Date: March 1, 2006
Creator: Yamashita, Tomohiro & U., /Okayama
Partner: UNT Libraries Government Documents Department
open access

Measurement of 1/sigma dsigma/dy for Z/gamma* ---> e+e- at s**(1/2) = 1.96 TeV

Description: The author presents the measurement of p{bar p} {yields} Z/{gamma}* {yields} e{sup +}e{sup -} + X inclusive differential cross section as a function of boson rapidity. The data, which correspond to an integrated luminosity of 0.4 fb{sup -1}, were collected with D0 detector at Tevatron p{bar p} collider. At the Run II energy of {radical}s = 1.96 TeV, Z bosons are produced with rapidity out to {+-} 3. The cross section is measured in a mass range between 71 to 111 GeV for the allowed kinematic ra… more
Date: March 1, 2007
Creator: Yan, Ming
Partner: UNT Libraries Government Documents Department
open access

Inclusive jet production studies at the Tevatron using the CDF detector

Description: Quantum Chromodynamics (QCD) is the gauge theory that governs the strong interactions between quarks and gluons inside hadrons like, for example, protons and neutrons. It shows two well established characteristics, related to the non-Abelian nature of the theory, that dominate its phenomenology: asymptotic freedom and color confinement. The dependence of the strong coupling, {alpha}{sub s}(Q{sup 2}), with the hard scale is such that it decreases with decreasing the distance between partons. Thi… more
Date: March 1, 2007
Creator: Norniella, Olga
Partner: UNT Libraries Government Documents Department
open access

Search for the Higgs Boson Using High-pT Isolated Like-Sign Dil Events in 1.96-TeV Proton-Antiproton Collisions

Description: Our physics objective is to search for the neutral on using events containing a like-sign dilepton pair in the following reaction: q{bar q} {yields} W{sup {+-}} H {yields} W{sup {+-}} W*W* {yields} {ell}{sup {+-}}{ell}{sup {+-}} + X. The relevant Higgs boson mass region is above 160 GeV/c{sup 2} for the Standard Model Higgs boson where the branching fraction of H {yields} W*W* supersedes that of H {yields} b{bar b}. The search for this signature in the region at low mass (less than 135 GeV/c{su… more
Date: March 1, 2005
Creator: Kobayashi, Hirokazu
Partner: UNT Libraries Government Documents Department
open access

Measurement of z0 gamma production in ppbar collisions at s**(1/2) = 1.96 TeV

Description: The cross-section of p{bar p} {yields} Z{sup 0}{gamma} + X production at {radical}s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron is measured using 202 pb{sup -1} of data from March 2002 to September 2003, collected with high P{sub T} lepton triggers. The number of events observed and their kinematic distributions are compared to the NLO Standard Model prediction in both the Z{sup 0} {yields} e{sup +}e{sup -} and Z{sup 0} {yields} {mu}{sup +}{mu}{sup -} channels. For a minimum l… more
Date: March 1, 2005
Creator: Hayward, Helen Sarah
Partner: UNT Libraries Government Documents Department
open access

Determining Application Runtimes Using Queueing Network Modeling

Description: Determination of application times-to-solution for large-scale clustered computers continues to be a difficult problem in high-end computing, which will only become more challenging as multi-core consumer machines become more prevalent in the market. Both researchers and consumers of these multi-core systems desire reasonable estimates of how long their programs will take to run (time-to-solution, or TTS), and how many resources will be consumed in the execution. Currently there are few methods… more
Date: March 15, 2007
Creator: Elliott, M
Partner: UNT Libraries Government Documents Department
open access

A study of muon neutrino to electron neutrino oscillations in the MINOS experiment

Description: The observation of neutrino oscillations (neutrino changing from one flavor to another) has provided compelling evidence that the neutrinos have non-zero masses and that leptons mix, which is not part of the original Standard Model of particle physics. The theoretical framework that describes neutrino oscillation involves two mass scales ({Delta}m{sub atm}{sup 2} and {Delta}m{sub sol}{sup 2}), three mixing angles ({theta}{sub 12}, {theta}{sub 23}, and {theta}{sub 13}) and one CP violating phase… more
Date: March 1, 2009
Creator: Yang, Tingjun
Partner: UNT Libraries Government Documents Department
open access

First evidence for WW and WZ diboson production with semi-leptonic decays at a Hadron Collider

Description: Presented is a measurement of the simultaneous production of a W{sup {+-}} boson in association with a second weak boson (W{sup {+-}} or Z{sup 0}) in p{bar p} collisions at {radical}s = 1.96 TeV. Events are consider with one electron or one muon, missing transverse energy, and at least two hadronic jets. The data were collected by the D0 detector in Run IIa of the Tevatron accelerator and correspond to 1.07 fb{sup -1} of integrated luminosity for each of the two channels (WW/WZ {yields} e{nu}q{… more
Date: March 1, 2009
Creator: Haley, Joseph Glenn Biddle
Partner: UNT Libraries Government Documents Department
open access

Testing CPT conservation using the NuMI neutrino beam with the MINOS experiment

Description: The MINOS experiment was designed to measure neutrino oscillation parameters with muon neutrinos. It achieves this by measuring the neutrino energy spectrum and flavor composition of the man-made NuMI neutrino beam 1km after the beam is formed and again after 735 km. By comparing the two spectra it is possible to measure the oscillation parameters. The NuMI beam is made up of 7.0%$\bar{v}$<sub>μ</sub>, which can be separated from the v<sub>μ</sub> because the MINOS detectors are magnetized. Thi… more
Date: March 1, 2010
Creator: Auty, David John
Partner: UNT Libraries Government Documents Department
open access

Measurement of the single top production cross section in proton-antiproton collisions at 1.96 TeV

Description: This thesis describes a search for singly produced top quarks via an electroweak vertex in head-on proton-antiproton collisions at a center of mass energy of √s = 1.96 TeV. The analysis uses a total of 2.3 fb<sup>-1</sup> of data collected with the D0 detector at Fermilab, corresponding to two different run periods of the Tevatron collider. Two channels contribute to single top quark production at the Tevatron, the s-channel and the t-channel. In the s-channel, a virtual W boson is produced fro… more
Date: March 25, 2010
Creator: Tanasijczuk, Andres Jorge
Partner: UNT Libraries Government Documents Department
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