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t anti-t production cross section measurement using soft electron tagging in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: We measure the production cross section of t{bar t} events in p{bar p} collisions at {radical}s = 1.96 TeV. The data was collected by the CDF experiment in Run 2 of the Tevatron accelerator at the Fermi National Accelerator Laboratory between 2002 and 2007. 1.7 fb{sup -1} of data was recorded during this time period. We reconstruct t{bar t} events in the lepton+jets channel, whereby one W boson - resulting from the decay of the top quark pairs - decays leptonically and the other hadronically. T… more
Date: September 1, 2008
Creator: Chou, John Paul & U., /Harvard
Partner: UNT Libraries Government Documents Department
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Observations and Measurements of Orbitally Excited L=1 B Mesons at the D0 Experiment

Description: This thesis describes investigations of the first set of orbitally excited (L = 1) states for both the B{sub d}{sup 0} and B{sub s}{sup 0} meson systems (B**{sub d} and B**{sub s}). The data sample corresponds to 1.35 fb{sup -1} of integrated luminosity, collected in 2002-2006 by the D0 detector, during the Run IIa operation of the Tevatron p{bar p} colliding beam accelerator. The B**{sub d} states are fully reconstructed in decays to B{sup (*)+} {pi}{sup -}, with B{sup (*)+} {yields} {gamma} J… more
Date: September 1, 2008
Creator: Williams, Mark Richard James
Partner: UNT Libraries Government Documents Department
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Hard photo-disintegration of proton pairs in {sup 3}He nuclei

Description: Extensive studies of high-energy deuteron photodisintegration over the past two decades have probed the limits of meson-baryon descriptions of nuclei and nuclear reactions. At high energies, photodisintegration cross sections have been shown to scale as a power law in s (the total cm energy squared), which suggests that quarks are the relevant degrees of freedom. In an attempt to more clearly identify the underlying dynamics at play, JLab/Hall A experiment 03-101 measured the hard photodisinteg… more
Date: September 1, 2011
Creator: Pomerantz, Ishay
Partner: UNT Libraries Government Documents Department
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Search for Supersymmetry in the Dilepton Final State with Taus at CDF Run II

Description: This thesis presents the results a search for chargino and neutralino supersymmetric particles yielding same signed dilepton final states including one hadronically decaying tau lepton using 6.0 fb{sup -1} of data collected by the the CDF II detector. This signature is important in SUSY models where, at high tan {beta}, the branching ratio of charginos and neutralinos to tau leptons becomes dominant. We study event acceptance, lepton identification cuts, and efficiencies. We set limits on the p… more
Date: September 1, 2011
Creator: Forrest, Robert David
Partner: UNT Libraries Government Documents Department
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Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

Description: Large extra dimensions (LED) have been proposed to account for the apparent weakness of gravitation. These theories also indicate that the postulated massive Kaluza-Klein (KK) gravitons may be produced by nucleon-nucleon bremsstrahlung in the course of core collapse of supernovae. Hannestad and Raffelt have predicted energy spectra of gamma ray emission from the decay of KK gravitons trapped by the gravity of the remnant neutron stars (NS). These and other authors have used EGRET data on NS to … more
Date: September 19, 2012
Creator: Berenji, Bijan & /Stanford U., Appl. Phys. Dept. /SLAC
Partner: UNT Libraries Government Documents Department
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A Search for Neutral Supersymmetric Higgs Bosons at D0

Description: A search for Higgs bosons in multijet data from the D0 detector is reported in this thesis. The Higgs boson is the only remaining undiscovered particle in the Standard Model of particle physics, and plays an integral role in this model. It is known that this model is not a complete description of fundamental physics (it does not describe gravity, for example), and so searches for physics beyond the Standard Model are an important part of particle physics. One extension of the Standard Model, th… more
Date: September 1, 2010
Creator: Osman, Nicolas Ahmed
Partner: UNT Libraries Government Documents Department
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Measurement of the Neutron electric form factor at Q2=0.8 2(GeV\\c)

Description: Nucleon form factors allow a sensitive test for models of the nucleon. Recent experiments utilising polarisation observables have resulted, for the first time, in a model-independent determination of the neutron electric form factor GnE. This method employed an 80% longitudinally polarised, high intensity (10 uA) electon beam (883 MeV) that was quasi-elastically scattered off a liquid deuterium target in the reaction D (e, en)p. A neutron polarimeter was designed and installed to measure the ra… more
Date: September 30, 2007
Creator: Glazier, Derek
Partner: UNT Libraries Government Documents Department
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Analysis of Bs flavor oscillations at CDF

Description: The search for and study of flavor oscillations in the neutral B{sub s}B{sub s} meson system is an experimentally challenging task. It constitutes a flagship analysis of the Tevatron physics program. In this dissertation, they develop an analysis of the time-dependent B{sub s} flavor oscillations using data collected with the CDF detector. The data samples are formed of both fully and partially reconstructed B meson decays: B{sub s} {yields} D{sub s}{pi}({pi}{pi}) and B{sub s} {yields} D{sub s}… more
Date: September 1, 2006
Creator: Leonardo, Nuno T.
Partner: UNT Libraries Government Documents Department
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Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

Description: Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish a… more
Date: September 18, 2002
Creator: Wang, Tong
Partner: UNT Libraries Government Documents Department
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An optimised oscillation analysis of MINOS beam data

Description: This thesis presents results of the MINOS long baseline neutrino oscillation experiment. Charged Current interactions of {nu}{sub {mu}} from the NuMI beamline have been recorded in both the Near and Far Detectors between May 2005 and February 2006, corresponding to 1.27 x 10{sup 20} protons being delivered to the NuMI target. Several techniques for improving the sensitivity of an oscillation measurement are discussed and their impact assessed. 378 events are observed in the Far Detector during … more
Date: September 1, 2007
Creator: Culling, Andrew John & U., /Cambridge
Partner: UNT Libraries Government Documents Department
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Search for Rare Multi-Pion Decays of the Tau Lepton Using the BABAR Detector

Description: A search for the decay of the {tau} lepton to rare multi-pion final states is performed using the BABAR detector at the PEP-II asymmetric-energy e+e- collider. The analysis uses 232 fb-1 of data at center-of-mass energies on or near the {Upsilon}(4S) resonance. In the search for the {tau}- {yields} 3{pi}-2{pi}+2{pi}{sup 0}{nu}{sub {tau}} decay, we observe 10 events with an expected background of 6.5{sup +2.0}{sub -1.4} events. In the absence of a signal, we calculate the decay branching ratio u… more
Date: September 18, 2007
Creator: Ter-Antonyan, Ruben
Partner: UNT Libraries Government Documents Department
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Atmospheric neutrino observations in the MINOS far detector

Description: This thesis presents the results of atmospheric neutrino observations from a 12.23 ktyr exposure of the 5.42 kt MINOS Far Detector between 1st August 2003 until 1st March 2006. The separation of atmospheric neutrino events from the large background of cosmic muon events is discussed. A total of 277 candidate contained vertex {nu}/{bar {nu}}{sub {mu}} CC data events are observed, with an expectation of 354.4{+-}47.4 events in the absence of neutrino oscillations. A total of 182 events have clear… more
Date: September 1, 2007
Creator: Chapman, John Derek & U., /Cambridge
Partner: UNT Libraries Government Documents Department
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Construction of Effective Electromagnetic Currents for Two-Body Quasipotential Equations

Description: A systematic algebraic approach for the construction of effective electro-magnetic currents consistent with relativistic two-body quasipotential equations is presented. This approach generalizes the Mandelstam formalism and applies it to a generic quasipotential reduction method. The use of Ward-Takahashi identities for the effective currents guarantees conservation of current matrix elements involving any combination of bound and scattering states. This approach is shown to reproduce previous … more
Date: September 1, 1998
Creator: Krioukov, Dmitri
Partner: UNT Libraries Government Documents Department
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Search for neutrino oscillations in the MINOS experiment by using quasi-elastic interactions

Description: The enthusiasm of the scientific community for studying oscillations of neutrinos is equaled only by the mass of their detectors. The MINOS experiment determines and compares the near spectrum of muonic neutrinos from the NUMI beam to the far one, in order to measure two oscillation parameters: {Delta}m{sub 23}{sup 2} and sin{sup 2} (2{theta}{sub 23}). The spectra are obtained by analyzing the charged current interactions which difficulty lies in identifying the interactions products (e.g. muon… more
Date: September 1, 2005
Creator: Piteira, Rodolphe
Partner: UNT Libraries Government Documents Department
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Study of B0 to D(*)0h0 Decay and Measurement ofsin(2beta)

Description: This thesis describes a measurement of a CP violating asymmetry in neutral B meson decays, B{sup 0} yields D{sup *0}h{sup 0}, where D{sup *0} is a charmed meson and h{sup 0} is a light meson, performed on data collected by the BABAR experiment at the SLAC asymmetric-energy electron-positron collider PEP-II.
Date: September 18, 2007
Creator: Bomben, Marco & /SLAC /Trieste U., DMI
Partner: UNT Libraries Government Documents Department
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Search for Diphoton Events with Large Missing Transverse Energy in 6.3 fb-1 of ppbar Collisions using the D0 Detector at the Fermilab Tevatron Collider

Description: A search for diphoton events with large missing transverse energy produced in p{bar p} collisions at {radical}s = 1.96 TeV is presented. The data were collected with the D0 detector at the Fermilab Tevatron Collider between 2002 and 2010, and correspond to 6.3 fb{sup -1} of integrated luminosity. The observed missing transverse energy distribution is well described by the Standard Model prediction, and 95% C.L. limits are derived on two realizations of theories beyond the Standard Model. In a g… more
Date: September 1, 2010
Creator: Cooke, Mark Stephen
Partner: UNT Libraries Government Documents Department
open access

DECAY PROPERTIES OF THE E HYPERON AND E RESONANCES

Description: A sample of 2500 {Xi}{sup -} and 500 {Xi}{sup 0} hyperons, produced in {Xi}K, {Xi}K{pi}, and {Xi}K{pi}{pi} final states by K{sup -} (in H{sub 2}) at incident momenta of 1.7 to 2.7 BeV/c, has been analyzed. The data are from an exposure (K-63) of 26 events/{mu}b in the 72-inch bubble chamber; approximately 85% of the {Xi}{sup -} events and 60% of the {Xi}{sup 0} events have been analyzed. For the {Xi}, they determine the spin and decay parameters a{sub {Xi}} and {Phi}{sub {Xi}} = tan{sup -1} ({b… more
Date: September 10, 1966
Creator: Merrill, Jr., Deane W.
Partner: UNT Libraries Government Documents Department
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The Higgs boson in the Standard Model theoretical constraints and a direct search in the wh channel at the Tevatron

Description: We have presented results in two different yet strongly linked aspects of Higgs boson physics. We have learned about the importance of the Higgs boson for the fate of the Standard Model, being either only a theory limited to explaining phenomena at the electroweak scale or, if the Higgs boson lies within a mass range of 130 &lt; m<sub>H</sub> &lt; 160 GeV the SM would remain a self consistent theory up to highest energy scales O(m<sub>Pl</sub>). This could have direct implications on theories o… more
Date: September 10, 2010
Creator: Huske, Nils Kristian & (Germany)], Bielefeld Univ.
Partner: UNT Libraries Government Documents Department
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Measurement of the Λ<sup>0</sup><sub>b</sub> lifetime in Λ<sup>0</sup><sub>b</sub> → Λ<sup>+</sup><sub>c</sub>π<sup>-</sup> decays at the Collider Detector at Fermilab

Description: The lifetime of the Λ<sup>0</sup><sub>b</sub> baryon (consisting of u, d and b quarks) is the theoretically most interesting of all b-hadron lifetimes. The lifetime of Λ<sup>0</sup><sub>b</sub> probes our understanding of how baryons with one heavy quark are put together and how they decay. Experimentally however, measurements of the Λ<sup>0</sup><sub>b</sub> lifetime have either lacked precision or have been inconsistent with one another. This thesis describes the measurement of Λ<sup>0</sup><… more
Date: September 1, 2008
Creator: Mumford, Jonathan Reid
Partner: UNT Libraries Government Documents Department
open access

NUCLEAR SPECTROSCOPIC STUDIES OF SOME VERY HEAVY ODD-MASS NUCLIDES

Description: The nuclear radiations of nuclides: U{sup 233}, Pu{sup 239}, Bk{sup 243}, Bk{sup 244}, Bk{sup 245}, Bk{sup 246}, Bk{sup 249}, Cf{sup 249}, and Fm{sup 255} were investigated with high-resolution spectrometers. The {alpha}-particle spectra of all nuclides except Bk{sup 249} were measured with 6 mm diameter surface-barrier detectors. Bk{sup 249} {alpha}-particles were analyzed with a double-focusing magnetic spectrograph. The {gamma}-singles were examined with the recently developed Ge(Li) and Si(… more
Date: September 20, 1966
Creator: Ahmad, Irshad
Partner: UNT Libraries Government Documents Department
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Energy Demands and Efficiency Strategies in Data Center Buildings

Description: Information technology (IT) is becoming increasingly pervasive throughout society as more data is digitally processed, stored, and transferred. The infrastructure that supports IT activity is growing accordingly, and data center energy demands haveincreased by nearly a factor of four over the past decade. Data centers house IT equipment and require significantly more energy to operate per unit floor area thanconventional buildings. The economic and environmental ramifications of continued data … more
Date: September 1, 2009
Creator: Shehabi, Arman
Partner: UNT Libraries Government Documents Department
open access

Beam Dynamics in a Muon Ionisation Cooling Channel

Description: The Neutrino Factory has been proposed as a facility to provide an intense source of neutrinos suitable for the measurement of neutrino oscillation parameters and a possible CP violating phase to unprecedented precision. In the Neutrino Factory, neutrinos are produced by the decay of a muon beam with 20-50 GeV per muon. Initially, the muon beam occupies a large volume in phase space, which must be reduced before the beam can be accelerated. The proposed method to achieve this is to use a soleno… more
Date: September 1, 2008
Creator: Rogers, Chris
Partner: UNT Libraries Government Documents Department
open access

Construction and testing of the scintillating fibre trackers for MICE

Description: The discovery of neutrino mass through experimental evidence of neutrino oscillations at the end of the last century has provided the first proof that the Standard Model of particle physics is incomplete. To be able to extend the Standard Model to incorporate massive neutrinos first requires many theoretical uncertainties surrounding the particle and its interactions to be understood. Therefore, a dedicated experimental programme is needed over the coming decades to provide precision measuremen… more
Date: September 1, 2009
Creator: Fish, Aron
Partner: UNT Libraries Government Documents Department
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