A 3% Measurement of the Beam Normal Single Spin Asymmetry in Forward Angle Elastic Electron-Proton Scattering using the Qweak Setup (open access)

A 3% Measurement of the Beam Normal Single Spin Asymmetry in Forward Angle Elastic Electron-Proton Scattering using the Qweak Setup

The beam normal single spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable of the imaginary part of the two-photon exchange process. Moreover, it is a potential source of false asymmetry in parity violating electron scattering experiments. The Q{sub weak} experiment uses parity violating electron scattering to make a direct measurement of the weak charge of the proton. The targeted 4% measurement of the weak charge of the proton probes for parity violating new physics beyond the Standard Model. The beam normal single spin asymmetry at Q{sub weak} kinematics is at least three orders of magnitude larger than 5 ppb precision of the parity violating asymmetry. To better understand this parity conserving background, the Q{sub weak} Collaboration has performed elastic scattering measurements with fully transversely polarized electron beam on the proton and aluminum. This dissertation presents the analysis of the 3% measurement (1.3% statistical and 2.6% systematic) of beam normal single spin asymmetry in electronproton scattering at a Q2 of 0.025 (GeV/c)2. It is the most precise existing measurement of beam normal single spin asymmetry available at the time. A measurement of this precision helps to improve the theoretical models on beam normal …
Date: August 1, 2013
Creator: Waidyawansa, Dinayadura Buddhini
System: The UNT Digital Library
Development of aerogel-lined targets for inertial confinement fusion experiments (open access)

Development of aerogel-lined targets for inertial confinement fusion experiments

None
Date: March 5, 2013
Creator: Braun, Tom
System: The UNT Digital Library
Double Beta Decay in Xenon-136: Measuring the Neutrino-Emitting Mode and Searching for Majoron-Emitting Modes (open access)

Double Beta Decay in Xenon-136: Measuring the Neutrino-Emitting Mode and Searching for Majoron-Emitting Modes

None
Date: August 23, 2013
Creator: Herrin, Steven
System: The UNT Digital Library
Exposure Evaluation for Benzene, Lead and Noise in Vehicle and Equipment Repair Shops (open access)

Exposure Evaluation for Benzene, Lead and Noise in Vehicle and Equipment Repair Shops

An exposure assessment was performed at the equipment and vehicle maintenance repair shops operating at the U. S. Department of Energy Hanford site, in Richland, Washington. The maintenance shops repair and maintain vehicles and equipment used in support of the Hanford cleanup mission. There are three general mechanic shops and one auto body repair shop. The mechanics work on heavy equipment used in construction, cranes, commercial motor vehicles, passenger-type vehicles in addition to air compressors, generators, and farm equipment. Services include part fabrication, installation of equipment, repair and maintenance work in the engine compartment, and tire and brake services. Work performed at the auto body shop includes painting and surface preparation which involves applying body filler and sanding. 8-hour time-weighted-average samples were collected for benzene and noise exposure and task-based samples were collected for lead dust work activities involving painted metal surfaces. Benzene samples were obtained using 3M™ 3520 sampling badges and were analyzed for additional volatile organic compounds. These compounds were selected based on material safety data sheet information for the aerosol products used by the mechanics for each day of sampling. The compounds included acetone, ethyl ether, toluene, xylene, VM&P naphtha, methyl ethyl ketone, and trichloroethylene. Laboratory data …
Date: April 10, 2013
Creator: Sweeney, Lynn C.
System: The UNT Digital Library
Imaging of Phase Objects using Partially Coherent Illumination (open access)

Imaging of Phase Objects using Partially Coherent Illumination

None
Date: November 25, 2013
Creator: Ravizza, F. L.
System: The UNT Digital Library
Investigation of the Charmless Decay B+- \rightarrow K+- K-+ K+- Using a Dalitz Plot Analysis at BaBar (open access)

Investigation of the Charmless Decay B+- \rightarrow K+- K-+ K+- Using a Dalitz Plot Analysis at BaBar

None
Date: June 10, 2013
Creator: Hart, Alistair Jepson & U., /Birmingham
System: The UNT Digital Library
Measurement of D0 - Anti-D0 Mixing With a Time-Dependent Amplitude Analysis of D0 \rightarrow K+ Pi- Pi0 (open access)

Measurement of D0 - Anti-D0 Mixing With a Time-Dependent Amplitude Analysis of D0 \rightarrow K+ Pi- Pi0

None
Date: June 10, 2013
Creator: Pelliccioni, Mario & U., /Turin
System: The UNT Digital Library
Measurement of Mixing and CP Violation in the Two-Body D0 decays to KK, pipi and Kpi with the BaBar Experiment (open access)

Measurement of Mixing and CP Violation in the Two-Body D0 decays to KK, pipi and Kpi with the BaBar Experiment

None
Date: January 18, 2013
Creator: Casarosa, Giulia
System: The UNT Digital Library
A Measurement of Neutral B Mixing using Di-Lepton Events with the BaBar Detector (open access)

A Measurement of Neutral B Mixing using Di-Lepton Events with the BaBar Detector

None
Date: June 11, 2013
Creator: Gunawardane, N.
System: The UNT Digital Library
A Measurement of the Branching Fractions and CP Asymmetries of the Decays B+ \to K*+ pi0 and B+ \to rho+ pi0 at BaBar (open access)

A Measurement of the Branching Fractions and CP Asymmetries of the Decays B+ \to K*+ pi0 and B+ \to rho+ pi0 at BaBar

None
Date: June 11, 2013
Creator: Gaillard, James Robert
System: The UNT Digital Library
A Measurement of the Exclusive Branching Fraction for B \to pi K at BaBar (open access)

A Measurement of the Exclusive Branching Fraction for B \to pi K at BaBar

None
Date: June 11, 2013
Creator: Aspinwall, L.
System: The UNT Digital Library
A Measurement of the Weak Charge of the Proton through Parity Violating Electron Scattering using the Qweak Apparatus: A 21% Result (open access)

A Measurement of the Weak Charge of the Proton through Parity Violating Electron Scattering using the Qweak Apparatus: A 21% Result

After a decade of preparations, the Qweak experiment at Jefferson Lab is making the first direct measurement of the weak charge of the proton, Q^p_W. This quantity is suppressed in the Standard Model making a good candidate for search for new physics beyond the SM at the TeV scale. Operationally, we measure a small (about -0.200 ppm) parity-violating asymmetry in elastic electron-proton scattering in integrating mode while flipping the helicity of the electrons 1000 times per second. Commissioning took place Fall 2010, and we finished taking data in early summer 2012. This dissertation is based on the data taken on an initial two weeks period (Wien0). It will provide an overview of the Qweak apparatus, description of the data acquisition and analysis software systems, and final analysis and results from the Wien0 data set. The result is a 16% measurement of the parity violating electron-proton scattering asymmetry, A = -0.2788 +/- 0.0348 (stat.) +/- 0.0290 (syst.) ppm at Q^2 = 0.0250 +/- 0.0006 (GeV)^2. From this a 21% measurement of the weak charge of the proton, Q_w^p(msr)= +0.0952 +/- 0.0155 (stat.) +/- 0.0131 (syst.) +/- 0.0015 (theory) is extracted. From this a 2% measurement of the weak mixing angle, sin^2theta_W(msr)= …
Date: August 1, 2013
Creator: Beminiwattha, Rakitha
System: The UNT Digital Library
Meausrement of the Neutron Radius of {sup 208}Pb Through Parity Violation in Electron Scattering (open access)

Meausrement of the Neutron Radius of {sup 208}Pb Through Parity Violation in Electron Scattering

In contrast to the nuclear charge densities, which have been accurately measured with electron scattering, the knowledge of neutron densities still lack precision. Previous model-dependent hadron experiments suggest the difference between the neutron radius, R{sub n}, of a heavy nucleus and the proton radius, R{sub p}, to be in the order of several percent. To accurately obtain the difference, R{sub n}-R{sub p}, which is essentially a neutron skin, the Jefferson Lab Lead ({sup 208}Pb) Radius Experiment (PREX) measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 208}Pb at an energy of 1.06 GeV and a scattering angle of 5{degrees}#14;. Since Z{sup 0} boson couples mainly to neutrons, this asymmetry provides a clean measurement of R{sub n} with respect to R{sub p}. PREX was conducted at the Jefferson lab experimental Hall A, from March to June 2010. The experiment collected a final data sample of 2x#2;10{sup 7} helicity-window quadruplets. The measured parity-violating electroweak asymmetry A{sub PV} = 0.656 {+-}#6; 0.060 (stat) {+-}#6; 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions, R{sub n}-R{sub p} = 0.33{sup +0.16}{sub -0.18} fm and provides the #12;first electroweak observation of the neutron skin …
Date: May 31, 2013
Creator: Saenboonruang, Kiadtisak
System: The UNT Digital Library
Monte-Carlo Analysis of the Flavour Changing Neutral Current B \to Gamma at Babar (open access)

Monte-Carlo Analysis of the Flavour Changing Neutral Current B \to Gamma at Babar

None
Date: June 11, 2013
Creator: Smith, D.
System: The UNT Digital Library
Multitasking mesoporous nanomaterials for biorefinery applications (open access)

Multitasking mesoporous nanomaterials for biorefinery applications

Mesoporous silica nanoparticles (MSNs) have attracted great interest for last two decades due to their unique and advantageous structural properties, such as high surface area, pore volume, stable mesostructure, tunable pore size and controllable particle morphology. The robust silica framework provides sites for organic modifications, making MSNs ideal platforms for adsorbents and supported organocatalysts. In addition, the pores of MSNs provide cavities/ channels for incorporation of metal and metal oxide nanoparticle catalysts. These supported metal nanoparticle catalysts benefit from confined local environments to enhance their activity and selectivity for various reactions. Biomass is considered as a sustainable feedstock with potential to replace diminishing fossil fuels for the production of biofuels. Among several strategies, one of the promising methods of biofuel production from biomass is to reduce the oxygen content of the feedstock in order to improve the energy density. This can be achieved by creating C-C bonds between biomass derived intermediates to increase the molecular weight of the final hydrocarbon molecules. In this context, pore size and organic functionality of MSNs are varied to obtain the ideal catalyst for a C-C bond forming reaction: the aldol condensation. The mechanistic aspects of this reaction in supported heterogeneous catalysts are explored. The …
Date: May 2, 2013
Creator: Kandel, Kapil
System: The UNT Digital Library
Noise Exposure Summary And Comparitive Analyses (open access)

Noise Exposure Summary And Comparitive Analyses

None
Date: November 18, 2013
Creator: Bumala, P A
System: The UNT Digital Library
Proton form factor ratio, {mu}{sub p}G{sub E}{sup P}/G{sub M}{sup P} from double spin asymmetry (open access)

Proton form factor ratio, {mu}{sub p}G{sub E}{sup P}/G{sub M}{sup P} from double spin asymmetry

The form factors are fundamental properties of the nucleon representing the effect of its structure on its response to electromagnetic probes such as electrons. They are functions of the four-momentum transfer squared Q{sup 2} between the electron and the proton. This thesis reports the results of a new measurement of the ratio of the electric and magnetic form factors of the proton up to Q{sup 2} = 5.66 (GeV/c){sup 2} using the double spin asymmetry with a polarized beam and target. Experiment E07-003 (SANE, Spin Asymmetries of the Nucleon Experiment) was carried out in Hall C at Jefferson Lab in 2009 to study the proton spin structure functions with a dynamically polarized ammonia target and longitudinally polarized electron beam. By detecting elastically scattered protons in the High-Momentum Spectrometer (HMS) in coincidence with the electrons in the Big Electron Telescope Array (BETA), elastic measurements were carried out in parallel. The elastic double spin asymmetry allows one to extract the proton electric to magnetic form factor ratio G{sup p}{sub E}/G{sup p}{sub M} at high-momentum transfer, Q{sup 2} = 5.66 (GeV/c){sup 2}. In addition to the coincidence data, inclusively scattered electrons from the polarized ammonia target were detected by HMS, which allows to …
Date: August 1, 2013
Creator: Pushpakumari, Habarakada L. A.
System: The UNT Digital Library
Radiative Bottomonium Spectroscopy at the Y(2, 3S) Resonances at BaBar (open access)

Radiative Bottomonium Spectroscopy at the Y(2, 3S) Resonances at BaBar

None
Date: August 26, 2013
Creator: Lewis, Peter M.
System: The UNT Digital Library
Scalable Domain Decomposed Monte Carlo Particle Transport (open access)

Scalable Domain Decomposed Monte Carlo Particle Transport

None
Date: December 5, 2013
Creator: O'Brien, M. J.; Brantley, P. S.; Joy, K. I. & Gygi, F.
System: The UNT Digital Library
Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis (open access)

Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.
Date: March 14, 2013
Creator: Meyer, Matthew W.
System: The UNT Digital Library
Search for Di-Muon Decays of a Light Scalar Higgs Boson in Radiative Upsilon(1S) Decays (open access)

Search for Di-Muon Decays of a Light Scalar Higgs Boson in Radiative Upsilon(1S) Decays

None
Date: October 7, 2013
Creator: Prasad, Vindhyawasini & /Indian Inst. Tech,. Guwahati
System: The UNT Digital Library
Search for New and Unusual Stangonia using CLAS (open access)

Search for New and Unusual Stangonia using CLAS

We perform a survey of the proton, K^+, K^- -3 charged track data, taken by the CLAS detector for the HyCLAS experiment during the g12 run-period at Jefferson Lab. We aim to study the strong decay amplitudes, partial widths and production channels of strangeonia from the CLAS g12 dataset. HyCLAS was motivated by the experimental results for gluonic hybrid meson candidates, theoretical Lattice QCD, and Flux-tube Model calculations and predictions. The experiment was designed and conducted to search and observe new forms of hadronic matter through photoproduction.
Date: March 1, 2013
Creator: Saini, Mukesh Satyapraka
System: The UNT Digital Library