2026-09-20T00:14:25Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/1504602026-06-16T18:17:30Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022
Conrad, Janet M.
Axani, Spencer Nicholas Gaelan,
author.
Massachusetts Institute of Technology. Department of Physics.
Massachusetts Institute of Technology. Department of Physics
2023-04-07T16:54:30Z
2023-04-07T16:54:30Z
2020
2020
https://hdl.handle.net/1721.1/150460
1373625353
Thesis: Sc. D., Massachusetts Institute of Technology, Department of Physics, 2020
"The following pages, 92-94, were not included in the original document submitted to the MIT Libraries. This is the most complete copy available"--Disclaimer page. Cataloged from PDF version of thesis. Supervised by Janet M. Conrad.
Includes bibliographical references (pages 217-239).
The IceCube Neutrino Observatory is capable of performing a unique search for sterile neutrinos through the exploitation of a matter enhanced resonant neutrino oscillation phenomena. As atmospheric muon neutrinos pass the dense material within the Earth, neutral current elastic forward scattering is predicted to induce a transition into a sterile state. This thesis presents two 3+1 sterile neutrino analyses by searching for spectral differences in the reconstructed energy and zenith direction of muon neutrino events, indicative of a transition into a sterile state. The first search probes the parameter space [delta]m²₄₁ and sin²(2[theta]₂₄) with relevant sensitivity to the global best fit region for a 3+1 sterile neutrino hypothesis. The second search performs a scan through sin²(2[theta]₂₄) and sin²([theta]₃₄) in the oscillation averaged out region of high-[delta]m²₄₁ ([theta]²₄₁ >~ 10 eV²). The analyses are performed using an improved event selection, which was found to extract 305,891 well reconstructed muon neutrino events with a sample purity above 99.9%, from eight years of IceCube data. Novel simulation techniques, along with updated calibration, and a re-assessment of the systematic uncertainties are also discussed. The first analysis finds a best fit sterile hypothesis point at [theta]²₄₁ = 4.47eV² and sin²([theta]₂₄ = 0.10, consistent with the no-sterile hypothesis at the 8% confidence level. The second analysis finds a best fit sterile hypothesis at sin²([theta]₃₄ = 0.40, sin²([theta]₃₄ =0.006, consistent with the null hypothesis at the 19% confidence level.
by Spencer Nicholas Gaelan Axani.
Sc.D.
Sc. D. Massachusetts Institute of Technology, Department of Physics
239 pages
eng
Massachusetts Institute of Technology
MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.
http://dspace.mit.edu/handle/1721.1/7582
Physics.
Sterile neutrino searches at the Icecube Neutrino Observatory
Thesis
application/pdf
2023-04-07T16:54:30Z
Publication
Doctoral
unknown
unknown
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<Abstract>The IceCube Neutrino Observatory is capable of performing a unique search for sterile neutrinos through the exploitation of a matter enhanced resonant neutrino oscillation phenomena. As atmospheric muon neutrinos pass the dense material within the Earth, neutral current elastic forward scattering is predicted to induce a transition into a sterile state. This thesis presents two 3+1 sterile neutrino analyses by searching for spectral differences in the reconstructed energy and zenith direction of muon neutrino events, indicative of a transition into a sterile state. The first search probes the parameter space [delta]m²₄₁ and sin²(2[theta]₂₄) with relevant sensitivity to the global best fit region for a 3+1 sterile neutrino hypothesis. The second search performs a scan through sin²(2[theta]₂₄) and sin²([theta]₃₄) in the oscillation averaged out region of high-[delta]m²₄₁ ([theta]²₄₁ >~ 10 eV²). The analyses are performed using an improved event selection, which was found to extract 305,891 well reconstructed muon neutrino events with a sample purity above 99.9%, from eight years of IceCube data. Novel simulation techniques, along with updated calibration, and a re-assessment of the systematic uncertainties are also discussed. The first analysis finds a best fit sterile hypothesis point at [theta]²₄₁ = 4.47eV² and sin²([theta]₂₄ = 0.10, consistent with the no-sterile hypothesis at the 8% confidence level. The second analysis finds a best fit sterile hypothesis at sin²([theta]₃₄ = 0.40, sin²([theta]₃₄ =0.006, consistent with the null hypothesis at the 19% confidence level.</Abstract>
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