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dc.contributor.advisorKopp, Sachaen
dc.creatorRatchford, Jasmine Star Yuko Maen
dc.date.accessioned2012-07-17T14:28:40Zen
dc.date.available2012-07-17T14:28:40Zen
dc.date.issued2012-05en
dc.date.submittedMay 2012en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2012-05-4960en
dc.descriptiontexten
dc.description.abstractNeutrinos (v) are interesting for many reasons; they are the only fundamental fermions which are electrically neutral; their mass is orders of magnitude smaller than the lightest charged lepton, the electron; and their solely weak interactions make them an excellent probe of the weak nuclear force. However, one of the most interesting aspects of neutrinos is that, unlike their charged lepton partners, neutrino mass and flavor eigenstates are not the same. All leptons possess 'lepton flavor', a property which is conserved in neutrino interactions. However, because of the difference in the mass and weak eigenstates of neutrinos, a quantum-interference effect is seen in the time evolution of neutrinos. This results in energy and distance dependent oscillations of the neutrino's lepton flavor called 'neutrino oscillations'. The MINOS experiment (Main Injector Neutrino Oscillation Search) was designed to measure the neutrino oscillation parameters, [Delta]m²₃₂ and sin²(2[theta]₃₂). MINOS is composed of two detectors located on a 'beam' of v[subscript mu]s. The MINOS Near Detector is located at Fermilab, and the Far Detector is located at the Soudan Mine in Minnesota, 734 km after the Near Detector. The MINERvA experiment (Main Injector Neutrino Experiment for v - A) is a neutrino experiment placed directly in front of the MINOS Near Detector. MINERvA's goal is to make precision measurements of neutrino cross sections. This will help with uncertainties in oscillation measurements, such as MINOS' at low energy. Although lepton flavor is conserved in neutrino interactions, the final state lepton can be a charged lepton ('charged current' interactions) or a neutrino ('neutral current' interactions) of a particular flavor. The identification of charged current ν[subscript mu] interactions through the identification of a muon in the final state is a critical component to both neutrino oscillation and cross section measurements; neutral current events are a background to the oscillation signal because the properties of the incoming neutrino cannot be determined. Such identification is particularly difficult and important for low-energy neutrino events. In this thesis, we will discuss improvements to the MINOS charged current identification at low energies, studies to estimate the effect of the neutral current background on the measurement of the oscillation parameters, and the aspects of muon identification which are similar for the MINOS and MINERvA experiments. In 2010, the MINOS experiment released a measurement of the oscillation parameters based on 7.32x10²⁰POT. The results were [Delta]m²₃₂ = 2.32⁺⁰̇¹²[subscript 0.08] x 10³eV², and sin²(2[theta]₃₂) > 0.90(90%,C.L.). This is the best measurement of the oscillation parameter, [Delta]m²₃₂, and a competitive measurement of sin²(2[theta]₃₂). The improvements to the charged current event selection helped MINOS observe a complete oscillation in neutrino energy.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subjectNeutrino oscillationen
dc.subjectMuonen
dc.titleIdentifying muons for neutrino oscillation and cross section experimentsen
dc.date.updated2012-07-17T14:28:57Zen
dc.identifier.slug2152/ETD-UT-2012-05-4960en
dc.contributor.committeeMemberLang, Karolen
dc.contributor.committeeMemberMarkert, Christinaen
dc.contributor.committeeMemberRitchie, Jacken
dc.contributor.committeeMemberSneden, Christopheren
dc.description.departmentPhysicsen
dc.type.genrethesisen
thesis.degree.departmentPhysicsen
thesis.degree.disciplinePhysicsen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen


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