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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Measurement of the muon neutrino inclusive charged current cross section on iron using the MINOS detector

Loiacono, Laura Jean 07 January 2011 (has links)
The Neutrinos at the Main Injector (NuMI) facility at Fermi National Accelerator Laboratory (FNAL) produces an intense muon neutrino beam used by the Main Injector Neutrino Oscillation Search (MINOS), a neutrino oscillation experiment, and the Main INjector ExpeRiment [nu]-A, (MINER[nu]A), a neutrino interaction experiment. Absolute neutrino cross sections are determined via [mathematical equation], where the numerator is the measured number of neutrino interactions in the MINOS Detector and the denominator is the flux of incident neutrinos. Many past neutrino experiments have measured relative cross sections due to a lack of precise measurements of the incident neutrino flux, normalizing to better established reaction processes, such as quasielastic neutrino-nucleon scattering. But recent measurements of neutrino interactions on nuclear targets have brought to light questions about our understanding of nuclear effects in neutrino interactions. In this thesis the [nu subscript mu] inclusive charged current cross section on iron is measured using the MINOS Detector. The MINOS detector consists of alternating planes of steel and scintillator. The MINOS detector is optimized to measure muons produced in charged current [nu subscript mu] interactions. Along with muons, these interactions produce hadronic showers. The neutrino energy is measured from the total energy the particles deposit in the detector. The incident neutrino flux is measured using the muons produced alongside the neutrinos in meson decay. Three ionization chamber monitors located in the downstream portion of the NuMI beamline are used to measure the muon flux and thereby infer the neutrino flux by relation to the underlying pion and kaon meson flux. This thesis describes the muon flux instrumentation in the NuMI beam, its operation over the two year duration of this measurement, and the techniques used to derive the neutrino flux. / text
62

Measurement of Muon Neutrino Disappearance with the T2K Experiment

Wongjirad, Taritree January 2014 (has links)
<p>We describe the measurement of muon neutrino disappearance due to</p><p>neutrino oscillation using the Tokai-2-Kamiokande (T2K) experiment's Run 1-4 (6.57&times;10<super>20</super> POT)</p><p>data set. We analyze the data using the conventional</p><p>Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing</p><p>matrix for the three Standard Model neutrinos. The output of the</p><p>analysis is a measurement of the parameters sin<super>2</super>&theta;<sub>23</sub>, &Delta;m<super>2</super><sub>32</sub> for the normal hierarchy and sin<super>2</super>&theta;<sub>23</sub>, &Delta;m<super>2</super><sub>13</sub> for</p><p>the inverted hierarchy. The best-fit oscillation</p><p>parameters for the normal hierarchy are found to be</p><p>(sin<super>2</super>&theta;<sub>23</sub>, &Delta;m<super>2</super><sub>32</sub>) = ( 0.514, 2.51&times;10<super>-3</super> eV<super>2</super>/c<super>4</super>}). The 90% 1D confidence interval -- determined for both parameters</p><p>using the Feldman-Cousins procedure -- is for the normal hierarchy</p><p>0.428 < sin<super>2</super>&theta;<sub>23</sub> < 0.598 and</p><p>2.34&times;10<super>-3</super> eV<super>2</super>/c<super>4</super> < &Delta;m<super>2</super><sub>32</sub> < 2.68\times10^{-3} eV<super>2</super>/c<super>4</super>. </p><p>For the inverted hierarchy, the best-fit oscillation parameters are</p><p>(sin<super>2</super>&theta;<sub>23</sub>, &Delta;m<super>2</super><sub>13</sub>) = (0.511, 2.48&times;10<super>-3</super> eV<super>2</super>/c<super>4</super>. The 90\% 1D Feldman-Cousins confidence intervals for the inverted hierarchy are 2.31&times;10<super>-3</super> eV<super>2</super>/c<super>4</super> < \Delta m^2_{13} < 2.64&times;10<super>-3</super> eV<super>2</super>/c<super>4</super>.</p> / Dissertation
63

Measurement of the delta and eta muon decay parameters

Hillairet, Anthony 09 June 2010 (has links)
Muon decay is a unique process involving only the four leptons of the first two generations. This makes it an ideal framework to study the weak interaction. The momentum-angle spectrum of the decay positron can be studied using a general 4-fermion interaction model. Only four parameters are needed in this model to entirely describe the spectrum. The measurement of these four muon decay parameters, rho, eta, delta and Pmu xi, provide a direct test of the Standard Model and its extensions. This thesis presents the final results from the blind analysis of the decay parameter delta using the TWIST (TRIUMF Weak Interaction Symmetry Test) spectrometer. The new precision on the parameter delta is a factor of 11.5 better than the last experimental result prior to TWIST achieving the goal of the TWIST collaboration of an order of magnitude improvement. The challenging parameter eta is also measured from the momentum-angle spectrum for the first time since 1969 with a precision improved by a factor of 7.4. The results are included in a global analysis to obtain stringent limits on some of the coupling constants of the 4-fermion interaction. The result of the measurement of delta are used to evaluate the possibility for a non-local tensor interaction.
64

The cosmic muon flux in the ATLAS Detector at the Large Hadron Collider

Hill, Ewan Chin 01 September 2011 (has links)
Many ATLAS analyses study events with muons in them including those searching for the Higgs boson and new physics. Cosmics muons, however, can also occasionally enter the detector and mimic the trajectory of a muon from one of the collisions produced by CERN’s Large Hadron Collider. By understanding the different ways ATLAS triggers on, collects, reconstructs, and analyses data from cosmic rays and collisions, the flux of cosmic muons with transverse momenta above 20 GeV in the central region of the detector was measured to be 1.34 ± 0.06 (stat.) s^−1 m^−2 . At the same time the cosmic muon charge ratio has been measured to be 1.3 ± 0.1 (stat.). This measurement of the cosmic muon flux in ATLAS is the first step in quantifying the sizes of the cosmic muon backgrounds to various physics analyses that look for events with muons. / Graduate
65

Search for Lepton Universality Violation Using Υ (3S) Decays

King, Gregory 23 December 2014 (has links)
The measurement of the ratio of the branching fractions of Υ (3S) decays into τ leptons over dimuons (R τ /μ = B(Υ (3S) → τ + τ − )/B(Υ (3S) → μ + μ − )) is a test of lepton universality. A violation of lepton universality would be evidence of new physics (and possibly of a light CP-odd Higgs boson). A sample of Υ (3S) decays (2.408 fb −1 ) collected with the B A B AR detector at the SLAC National Accelerator Laboratory was used to determine that the ratio R τ /μ is R τ /μ = 1.0385 ± 0.034 ± 0.019. Using the remaining blinded data sample (corresponding to an integrated luminosity of 25.6 fb −1 ) the estimated statistical sensitivity will be 1.1 % and the estimated systematic uncertainty of R τ /μ is 1.9 %. Prior to this work, previous measurements of R τ /μ had an estimated total precision of 10 %. / Graduate
66

The design and construction of the beam scintillation counter for CMS

Bell, Alan James January 2008 (has links)
This thesis presents the design qualification and construction of the Beam Scintillator Counter (BSC) for the CMS Collaboration at CERN in 2007 - 2008. The BSC detector is designed to aid in the commissioning of the Compact Muon Solenoid (CMS) during the first 2 years of operation and provide technical triggering for beam halo and minimum-bias events. Using plastic scintillator tiles mounted at both ends of CMS, it will detect minimum ionizing particles through the low-to-mid luminosity phases of the Large Hadron Collider (LHC) commissioning. During these early phases, the BSC will provide probably the most interesting and widely used data of any of the CMS sub-detectors and will be employed in the track based alignment procedure of the central tracker and commissioning of the Forward Hadron Calorimeter.
67

Muon probes of spin-polarized electrons in GaAs

Yokoyama, Koji, January 2009 (has links)
Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references (leaves 121-123). Issued in print and online. Available via ProQuest Digital Dissertations.
68

Muon spin spectroscopy and high magnetic field studies of novel superconductors and magnetic materials

Foronda, Francesca January 2016 (has links)
This thesis investigates a number of novel magnetic materials and high temperature superconductors using high-field magnetometry and muon spin spectroscopy (&mu;SR). The main measurement techniques are briefly described and a study of the dimer material [Cu(pyrazine)(glycine)]ClO<sub>4</sub> is presented to demonstrate the use of the proximity detector oscillator as a susceptometer in high magnetic fields. &mu;SR is a highly effective tool for probing magnetic order, spin freezing and spin dynamics. However, in some circumstances its performance may be impaired by the extent to which it perturbs the material under study. Using &mu;SR, density functional theory and crystal field calculations, I identify an experimental situation in the family of candidate quantum spin ices Pr<sub>2</sub>B<sub>2</sub>O<sub>7</sub> (B = Sn, Zr, and Hf), in which the measured response is dominated by a muon-induced distortion of the local structure. This issue is also addressed in a study of the spin dynamics in the canonical spin ice Ho2Ti2O7. Although computational work indicates a similar muon-induced effect in both Ho<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> and Dy<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub>, the &mu;SR data is not dominated by this perturbation. The remainder of this thesis is concerned with studying the superconducting properties of a number of Fe-based materials, including LiFeP which is found to have an enhanced superfluid stiffness in relation to its transition temperature. Also reported is the effect of structural disorder on the superconducting state in recently discovered Sr<sub>0.3</sub>(NH<sub>2</sub>)<sub>y</sub>(NH<sub>3</sub>)<sub>1-y</sub>Fe<sub>2</sub>Se<sub>2</sub>. Pulsed magnetic field measurements are used to probe the temperature dependence of the upper critical field, giving a maximum value of &mu;<sub>0</sub>H<sub>c2</sub>(0)&asymp;33(2) T. I also investigate the effect of intercalating additional ammonia, via reversible adsorption and desorption in the related superconductor Li<sub>x</sub>[(NH<sub>2</sub>)<sub>y</sub>(NH<sub>3</sub>)<sub>1-y</sub>]<sub>z</sub>Fe<sub>2</sub>Se<sub>2</sub> (z = 1, 2). These reactions were carried out in situ on the muon beamline so that the superfluid stiffness could be measured using transverse-field &mu;SR on a single sample.
69

Přesné měření oscilací elektronových antineutrin / Precise measurement of the electron antineutrino oscillation

Pěč, Viktor January 2016 (has links)
The Daya Bay experiment is designed to precisely measure short-baseline disappearance of reactor antineutrinos from reactor cores at the Daya Bay nuclear power plant complex in the Guangdong Province of China. It pre- sented the most precise measurements of oscillation parameters sin2 2θ13 = 0.084 ± 0.005 and |∆m2 ee| = (2.42 ± 0.11) × 10−3 eV2 . Background to the antineutrino signals is mainly created by cosmic muons and is effectively suppressed by use of water Cherenkov and RPC muon detectors. This thesis describe testing of RPC detectors prior to their installation at the experi- mental site. Part of the cosmic muons stop in the experiment's antineutrino detectors, and they decay or are captured by 12 C producing 12 B. Isotope 12 B contribute to accidental background. Rates of muon decays in the detectors are estimated in the thesis. The experiment can register electron antineutri- nos from supernova with expected signals around 20 MeV. Energy scale of the detectors at 53 MeV is determined.
70

Electron and muon anomalous magnetic dipole moment in the 3-3-1 model with heavy leptons / O momento de dipolo magnético anômalo do elétron e do múon no modelo 3-3-1 com léptons pesados

Santos, George de Conto 09 March 2018 (has links)
Submitted by GEORGE DE CONTO SANTOS null (georgedc@ift.unesp.br) on 2018-03-26T19:09:38Z No. of bitstreams: 1 Tese_doutorado.pdf: 1257592 bytes, checksum: 301d08e8373f7f6aeb4a2e0ce8f9f637 (MD5) / Approved for entry into archive by Hellen Sayuri Sato null (hellen@ift.unesp.br) on 2018-03-29T16:17:42Z (GMT) No. of bitstreams: 1 decontosantos_g_dr_ift.pdf: 1257592 bytes, checksum: 301d08e8373f7f6aeb4a2e0ce8f9f637 (MD5) / Made available in DSpace on 2018-03-29T16:17:42Z (GMT). No. of bitstreams: 1 decontosantos_g_dr_ift.pdf: 1257592 bytes, checksum: 301d08e8373f7f6aeb4a2e0ce8f9f637 (MD5) Previous issue date: 2018-03-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nós calculamos, no contexto do modelo 3-3-1 com léptons pesados carregados, vínculos sobre alguns dos parâmetros das partículas extras do modelo ao impor que suas contribuições aos fatores (g-2) do elétron e do múon estejam de acordo com os dados experimentais dentro de 1 sigma - 3 sigma. Para obter resultados realistas nós consideramos algumas das possíveis soluções das matrizes unitárias esquerda e direita que diagonalizam as matrizes de massa leptônicas, dando as massas leptônicas observadas e ao mesmo tempo acomodando a matriz de mistura de Pontecorvo-Maki-Nakagawa-Sakata (PMNS). Nós mostramos que, ao menos até a ordem de 1-loop, na faixa de parâmetros explorada, não é possível acomodar simultaneamente os fatores (g-2) do elétron e do múon a não ser que um dos léptons extras tenha massa da ordem de 20-40 GeVs e a escala de energia da simetria 331 esteja em torno de 60-80 TeVs. / We calculate, in the context of the 3-3-1 model with heavy charged leptons, constraints on some parameters of the extra particles in the model by imposing that their contributions to both the electron and muon (g-2) factors are in agreement with experimental data up to 1 sigma - 3 sigma. In order to obtain realistic results we use some of the possible solutions of the left- and right- unitary matrices that diagonalize the lepton mass matrices, giving the observed lepton masses and at the same time allowing to accommodate the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. We show that, at least up to 1-loop order, in the particular range of the space parameter that we have explored, it is not possible to fit the observed electron and muon (g-2) factors at the same time unless one of the extra leptons has a mass of the order of 20-40 GeVs and the energy scale of the 331 symmetry to be of around 60-80 TeVs. / 152740/2014-7

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