Measurement of 3-Flavour Neutrino Oscillation Parameters in the NOvA Experiment
- University Coll. London
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 $$\bar{ν}$$µ anti-neutrino beam. Neutrino oscillations are observed and measured by the analysis of νµ + $$\bar{ν}$$µ disappearance and νe + $$\bar{ν}$$e appearance in the beam, comparing the neutrino energy spectra in the Near and Far detectors means that neutrino oscillation parameters sin2 θ23, |Δ$$m^2_{32}$$|, and δCP can be constrained. This thesis presents the 2018 NOvA νµ+$$\bar{ν}$$µ disappearance, νe+$$\bar{ν}$$e 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 χ2 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 + $$\bar{ν}$$µ disappearance and νe + $$\bar{ν}$$e 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 Δ$$m^2_{32}$$ = (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.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1833585
- Report Number(s):
- FERMILAB-THESIS-2020-31; oai:inspirehep.net:1839075
- Country of Publication:
- United States
- Language:
- English
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