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Simulating the Growth of a Disk Galaxy and its Supermassive Black Hole in a Cosmological Simulating the Growth of a Disk Galaxy and its Supermassive Black Hole in a Cosmological Context

Description: Supermassive black holes (SMBHs) are ubiquitous in the centers of galaxies. Their formation and subsequent evolution is inextricably linked to that of their host galaxies, and the study of galaxy formation is incomplete without the inclusion of SMBHs. The present work seeks to understand the growth and evolution of SMBHs through their interaction with the host galaxy and its environment. In the first part of the thesis (Chap. 2 and 3), we combine a simple semi-analytic model of outflows from ac… more
Date: July 1, 2008
Creator: Levine, Robyn Deborah & /JILA, Boulder
Partner: UNT Libraries Government Documents Department
open access

A measurement of hadron production cross sections for the simulation of accelerator neutrino beams and a search for muon-neutrino to electron-neutrino oscillations in the delta m**2 about equals 1-eV**2 region

Description: A measurement of hadron production cross-sections for the simulation of accelerator neutrino beams and a search for muon neutrino to electron neutrino oscillations in the {Delta}m{sup 2} {approx} 1 eV{sup 2} region. This dissertation presents measurements from two different high energy physics experiments with a very strong connection: the Hadron Production (HARP) experiment located at CERN in Geneva, Switzerland, and the Mini Booster Neutrino Experiment (Mini-BooNE) located at Fermilab in Bata… more
Date: January 1, 2008
Creator: Schmitz, David W.
Partner: UNT Libraries Government Documents Department
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A study of muon neutrino disappearance with the MINOS detectors and the NuMI neutrino beam

Description: This thesis presents the results of an analysis of {nu}{sub {mu}} disappearance with the MINOS experiment, which studies the neutrino beam produced by the NuMI facility at Fermi National Accelerator Laboratory. The rates and energy spectra of charged current {nu}{sub {mu}} interactions are measured in two similar detectors, located at distances of 1 km and 735 km along the NuMI beamline. The Near Detector provides accurate measurements of the initial beam composition and energy, while the Far D… more
Date: June 1, 2008
Creator: Marshall, John Stuart & U., /Cambridge
Partner: UNT Libraries Government Documents Department
open access

Two-photon Photoemission of Organic Semiconductor Molecules on Ag(111)

Description: Angle- and time-resolved two-photon photoemission (2PPE) was used to study systems of organic semiconductors on Ag(111). The 2PPE studies focused on electronic behavior specific to interfaces and ultrathin films. Electron time dynamics and band dispersions were characterized for ultrathin films of a prototypical n-type planar aromatic hydrocarbon, PTCDA, and representatives from a family of p-type oligothiophenes.In PTCDA, electronic behavior was correlated with film morphology and growth modes… more
Date: May 15, 2008
Creator: Yang, Aram & Yang, Aram
Partner: UNT Libraries Government Documents Department
open access

Grid Development and a Study of B-flavour tagging at D�

Description: Run IIa of the D0 experiment at the Tevatron took place between Spring 2002 and Spring 2006, collecting approximately 1.2 fb{sup -1} of data. A fundamental principal of the D0 computing model is the utilization of globally distributed computing resources as part of a grid. In particular use is made of the 'SAMGrid'. The first part of this thesis describes the work undertaken at Imperial College on several D0 distributed computing projects. These included the deployment and development of parts … more
Date: September 1, 2006
Creator: Lewis, Philip William
Partner: UNT Libraries Government Documents Department
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Search for pair production of scalar top quarks in jets and missing transverse energy channel with the D0 detector

Description: This dissertation describes a search for the pair production of scalar top quarks, {tilde t}{sub 1}, using a luminosity of 995 pb{sup -1} of data collected in p{bar p} collisions with the D0 detector at the Fermilab Tevatron Collider at a center-of-mass energy {radical}s = 1.96 TeV. Both scalar top quarks are assumed to decay into a charm quark and a neutralino, {tilde {chi}}{sub 1}{sup 0}, where {tilde {chi}}{sub 1}{sup 0} is the lightest supersymmetric particle. This leads to a final state wi… more
Date: May 1, 2008
Creator: Shamim, Mansoora & U., /Kansas State
Partner: UNT Libraries Government Documents Department
open access

Time Dependent CP Asymmetries and Branching RatioMeasurements in Charmless Three Body B Decays at BABAR

Description: In this work we presented measurements of CP violation and decay rates of B decays in final states not involving a charm quark in the final state. In particular, the time-dependent CP asymmetries of decays which proceed through b {yields} s elementary transition is a particularly sensitive probe of physics beyond the Standard Model. In fact, even if the precise measurements of CP conserving and CP violating processes show the success of the CKM picture of the flavour physics, the sector of b {y… more
Date: July 17, 2007
Creator: Di Marco, Emanuele & U., /Rome
Partner: UNT Libraries Government Documents Department
open access

Control of Laser Plasma Based Accelerators up to 1 GeV

Description: This dissertation documents the development of a broadband electron spectrometer (ESM) for GeV class Laser Wakefield Accelerators (LWFA), the production of high quality GeV electron beams (e-beams) for the first time in a LWFA by using a capillary discharge guide (CDG), and a statistical analysis of CDG-LWFAs. An ESM specialized for CDG-LWFAs with an unprecedented wide momentum acceptance, from 0.01 to 1.1 GeV in a single shot, has been developed. Simultaneous measurement of e-beam spectra and … more
Date: December 3, 2007
Creator: Nakamura, Kei
Partner: UNT Libraries Government Documents Department
open access

Search for new physics coupling to the z boson

Description: We present the results of two searches for new particles that couple Z bosons in p{bar p} collisions at {radical}s = 1.96 TeV using the Collider Detector at Fermilab (CDF). In the first, we search for a long-lived parent of the Z boson using a data sample with a luminosity of 163 pb{sup -1}. Finding no significant excess above background, we set a limit on a fourth generation model as a function of mass and lifetime. In the second, we search for a particle that decays to a Z boson in conjunctio… more
Date: June 1, 2007
Creator: Scott, Adam Liddle
Partner: UNT Libraries Government Documents Department
open access

A Measurement of the muon neutrino charged current quasielastic interaction and a test of Lorentz violation with the MiniBooNE experiment

Description: The Mini-Booster neutrino experiment (MiniBooNE) at Fermi National Accelerator Laboratory (Fermilab) is designed to search for {nu}{sub {mu}} {yields} {nu}{sub e} appearance neutrino oscillations. Muon neutrino charged-current quasi-elastic (CCQE) interactions ({nu}{sub {mu}} + n {yields} {mu} + p) make up roughly 40% of our data sample, and it is used to constrain the background and cross sections for the oscillation analysis. Using high-statistics MiniBooNE CCQE data, the muon-neutrino CCQE c… more
Date: December 1, 2008
Creator: Katori, Teppei
Partner: UNT Libraries Government Documents Department
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Measurements of CP asymmetries and branching fractions of two-body charmless decays of B^0 and B^0_s mesons

Description: The thesis is organized as follows: Chapter 1 describes the theoretical framework of non-leptonic B{sub (s)}{sup 0} {yields} H{sup +}h{prime}{sup -} decays, with a simple overview of the CP violation mechanism within the Standard Model and of the most used phenomenological approaches in the evaluation of strong interaction contributions. The chapter contains also a review of the theoretical expectations and the current experimental measurements along with a discussion about the importance of st… more
Date: December 1, 2007
Creator: Morello, Michael Joseph & /Pisa, Scuola Normale Superiore
Partner: UNT Libraries Government Documents Department
open access

Diffractive Z/gamma* --> mu+mu- boson production in proton - antiproton collisions

Description: Measurements of the inclusive diffractive Z {yields} {mu}{sup +}{mu}{sup -} cross section with gap requirement for M{sub {mu}}{sub {mu}} > 40 GeV at {radical} s = 1.96 TeV and fraction of Z bosons produced diffractively with gap requirement from Z inclusive production are presented. The measurements are performed using a data sample corresponding to an integrated luminosity of 820 pb{sup -1}, collected with the D0 detector at the Tevatron, between 2002 to 2005. A total of 39945 di-muons even… more
Date: July 1, 2007
Creator: Mendoza Navas, Luis Miguel
Partner: UNT Libraries Government Documents Department
open access

Limit on the muon neutrino magnetic moment and a measurement of the CCPIP to CCQE cross section ratio

Description: A search for the muon neutrino magnetic moment was conducted using the Mini-BooNE low energy neutrino data. The analysis was performed by analyzing the elastic scattering interactions of muon neutrinos on electrons. The analysis looked for an excess of elastic scattering events above the Standard Model prediction from which a limit on the neutrino magnetic could be set. In this thesis, we report an excess of 15.3 {+-} 6.6(stat){+-}4.1(syst) {nu}{sub {mu}e} events above the expected background. … more
Date: July 1, 2008
Creator: Ouedraogo, Serge Aristide & U., /Louisiana State
Partner: UNT Libraries Government Documents Department
open access

A Study of Charged Current Single Charged Pion Productions on Carbon in a Few-GeV Neutrino Beam

Description: Understanding single charged pion production via neutrino-nucleus charged current interaction in the neutrino energy region of a few GeV is essential for future neutrino oscillation experiments since this process is a dominant background for {nu}{sub {mu}} {yields} {nu}{sub x} oscillation measurements. There are two contributions to this process: single pion production via baryonic resonance ({nu}{sub {mu}}N {yields} {mu}{sup -} N{pi}{sup +}) and coherent pion production interacting with the en… more
Date: January 1, 2009
Creator: Hiraide, Katsuki & U., /Kyoto
Partner: UNT Libraries Government Documents Department
open access

Search for the Higgs boson produced in association with a W boson at CDF Run II

Description: We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (p{bar p} {yields} W{sup {+-}}H {yields} {ell}{nu}b{bar b}) at a center of mass energy of 1.96 TeV. WH candidate events have a signature of a single lepton (E{sup {+-}}/{mu}{sup {+-}}), missing transverse energy, and two jets. The search looks for candidate events in approximately 2.7 fb{sup -1} of data recorded with the CDF II detector. The high-p{sub T} lepton (e,{mu}) i… more
Date: January 1, 2009
Creator: Slaunwhite, Jason Michael
Partner: UNT Libraries Government Documents Department
open access

MEASUREMENT OF Z + GAMMA PRODUCTION AND SEARCH FOR ANOMALOUS TRIPLE GAUGE COUPLINGS IN PROTON-ANTIPROTON COLLISIONS AT s**(1/2) = 1.96 TEV

Description: The author presents a measurement of p{bar p} {yields} Z{gamma} + X {yields} e{sup +}e{sup -}{gamma} + X production using proton-antiproton collisions data collected at the Collider Detector at Fermilab at a center of mass energy of 1.96 TeV. Z{gamma} production provides a direct test of the triple neutral gauge couplings. A measurement of Z{gamma} production cross section and search for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings are presented. The data presented are from 1.1 fb{sup -1} … more
Date: January 1, 2008
Creator: Deng, Jianrong & U., /Duke
Partner: UNT Libraries Government Documents Department
open access

Jet Energy Scale Studies and the Search for the Standard Model Higgs Boson in the Channel ZH -> nu anti-nu b anti-b at D�

Description: The D0 experiment is based at the Tevatron, which is currently the world's highest-energy accelerator. The detector comprises three major subsystems: the tracking system, the calorimeter and the muon detector. Jets, seen in the calorimeter, are the most common product of the proton-proton interactions at 2TeV. This thesis is divided into two parts. The first part focuses on jets and describes the derivation of a jet energy scale using p{bar p} {yields} (Z + jets) events as a cross-check of the … more
Date: November 1, 2006
Creator: Lobo, Lydia Mary Isis
Partner: UNT Libraries Government Documents Department
open access

Measurement of the top quark pair production cross-section in dimuon final states in proton-antiproton collisions at 1.96 TeV

Description: Particle physics deals with the fundamental building blocks of matter and their interactions. The vast number of subatomic particles can be reduced to twelve fundamental fermions, which interact by the exchange of spin-1 particles as described in the Standard Model (SM) of particle physics. The SM provides the best description of the subatomic world to date, despite the fact it does not include gravitation. Following the relation {lambda} = h/p, where h is Planck's constant, for the examination… more
Date: September 1, 2008
Creator: Konrath, Jens Peter
Partner: UNT Libraries Government Documents Department
open access

A measurement of the neutral current neutrino-nucleon elastic cross section at MiniBooNE

Description: The neutral current neutrino-nucleon elastic interaction {nu} N {yields} {nu} N is a fundamental process of the weak interaction ideally suited for characterizing the structure of the nucleon neutral weak current. This process comprises {approx}18% of neutrino events in the neutrino oscillation experiment, MiniBooNE, ranking it as the experiment's third largest process. Using {approx}10% of MiniBooNE's available neutrino data, a sample of these events were identified and analyzed to determine t… more
Date: February 1, 2008
Creator: Cox, David Christopher
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Diphoton Differential Cross Section in p anti-p Collisions at s**(1/2) = 1.96-TeV

Description: The diphoton differential cross-section as a function of mass up to 300 GeV/c{sup 2}, q{sub T} up to 100 GeV/c, and opening angle over a range of 0 to {pi} radians is measured. The measurement is performed using 1046.19 pb{sup -1} of data collected at Fermi National Accelerator Laboratory using the D0 detector. This analysis considers all direct diphoton states but attempts to suppress contributions due to fragmentation.
Date: January 1, 2007
Creator: Dyer, Joshua Marc
Partner: UNT Libraries Government Documents Department
open access

A Study of Factorization and a Measurement of CP Violation

Description: We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{sup 0}{bar B}{sup 0} decays collected between 1999 and 2004, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in … more
Date: January 16, 2008
Creator: Dahmes, Bryan
Partner: UNT Libraries Government Documents Department
open access

Measurement of CP Violation in B0 to Phi K0, and of Branching Fraction and CP Violation in B0 to F0(980) K0(S)

Description: The authors measure the time-dependent CP asymmetry parameters in B{sup 0} {yields} K{sup +}K{sup -}K{sup 0} based on a data sample of approximately 277 million B-meson pairs recorded at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II B-meson Factory at SLAC. They reconstruct two-body B{sup 0} decays to {phi}(1020)K{sub s}{sup 0} and {phi}(1020)K{sub L}{sup 0}. Using a time-dependent maximum-likelihood fit, they measure sin2{beta}{sub eff}({phi}K{sup 0}) = 0.48 {+-} 0.28 {+-} … more
Date: March 10, 2008
Creator: Kutter, Paul E.
Partner: UNT Libraries Government Documents Department
open access

An atmospheric muon neutrino disappearance measurement with the MINOS far detector

Description: It is now widely accepted that the Standard Model assumption of massless neutrinos is wrong, due primarily to the observation of solar and atmospheric neutrino flavor oscillations by a small number of convincing experiments. The MINOS Far Detector, capable of observing both the outgoing lepton and associated showering products of a neutrino interaction, provides an excellent opportunity to independently search for an oscillation signature in atmospheric neutrinos. To this end, a MINOS data set … more
Date: December 1, 2007
Creator: Gogos, Jeremy Peter
Partner: UNT Libraries Government Documents Department
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