Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.819926
Title: Measurement of 3-flavour neutrino oscillation parameters in the NOvA experiment
Author: Bending, Sebastian
ISNI:       0000 0004 9359 8995
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2020
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Abstract:
NOvA is a long-baseline neutrino oscillation experiment consisting of two functionally identical tracking calorimeters, a Near and Far Detector, that measure neutrino interactions induced by the Fermi National Accelerator Laboratory’s NuMI beam at baselines of 1 km and 810 km, respectively. The NuMI beam can be configured to produce either a primary νμ neutrino or ̄νμ anti-neutrino beam. Neutrino oscillations are observed and measured by the analysis of νμ + ̄νμ disappearance and νe + ̄νe appearance in the beam, comparing the neutrino energy spectra in the Near and Far detectors means that neutrino oscillation parameters sin2 θ23, |∆m2 32|, and δCP can be constrained. This thesis presents the 2018 NOvA νμ+ ̄νμ disappearance, νe+ ̄νe appearance, and combined analyses using both neutrino and anti-neutrino data, where oscillation fits have been performed, where possible, on an event-by-event basis rather than on a bin-by-bin basis as has conventionally been used in NOvA oscillation analyses. This allows for better precision in applying both neutrino oscillation probabilities and systematic uncertainties. Furthermore, oscillation analyses for the disappearance, appearance, and combined channels are presented using an unbinned likelihood fit and compared with the equivalent binned χ 2 likelihood fit used in the standard analysis. The 14 ktonne detector equivalent beam exposures used for this thesis are 8.85 × 1020 and 6.91 × 1020 protons on target for neutrino and antineutrino data respectively, corresponding to 5 years of NOvA data taking. A combined νμ + ̄νμ disappearance and νe + ̄νe appearance fit to the Far Detector data, assuming normal mass ordering and using the event-by-event oscillation and unbinned fitting methodologies, produces oscillation parameter constraints of ∆m2 32 = (2.50+0.08 −0.06) × 10−3 eV2 , sin2 θ23 = 0.59+0.02 −0.04, and δCP = 0.72+0.5 −0.9 π.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.819926  DOI: Not available
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