Sterile Neutrino Searches at the IceCube Neutrino Observatory

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 $\Delta$m${}_{41}^2$ and sin${}^2$(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 sin${}^2$(2${\theta }_{24}$) and sin${}^2$(2${\theta }_{34}$) in the oscillation averaged out region of high-$\Delta$m${}_{41}^2$ ($\Delta$m${}_{41}^2$ $\gtrsim$ 10eV${}^2$). 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 $\Delta$m${}_{41}^2$ = 4.47eV${}^2$ and sin${}^2$(${\theta }_{24})$ =0.10, consistent with the no-sterile hypothesis at the 8\% confidence level. The second analysis finds a best fit sterile hypothesis at sin${}^2$(${\theta }_{34})$ = 0.40, sin${}^2$(${\theta }_{24})$ = 0.006, consistent with the null hypothesis at the 19\% confidence level. % and provides a significant improvement in the worlds measurements using muon neutrino disappearance.

PhD thesis, MIT (2020)

References in corpus (25)

• The Reactor Antineutrino Anomaly
• Updated fit to three neutrino mixing: exploring the accelerator-reactor complementarity
• Observation and Characterization of a Cosmic Muon Neutrino Flux from the Northern Hemisphere using six years of IceCube data
• Calculation of atmospheric neutrino flux using the interaction model calibrated with atmospheric muon data
• Light Sterile Neutrinos: A White Paper
• Sterile neutrino search at NEOS Experiment
• Prompt neutrino fluxes from atmospheric charm
• Measurement of the proton-air cross-section at $\sqrt{s}=57$ TeV with the Pierre Auger Observatory
• Measurement of the multi-TeV neutrino cross section with IceCube using Earth absorption
• Uncertainties in Atmospheric Neutrino Fluxes
• Limits on nu_e and anti-nu_e disappearance from Gallium and reactor experiments
• Limits on sterile neutrino mixing using atmospheric neutrinos in Super-Kamiokande
• Perturbative charm production and the prompt atmospheric neutrino flux in light of RHIC and LHC
• Influence of hadronic interaction models and the cosmic ray spectrum on the high energy atmospheric muon and neutrino flux
• Search for Sterile Neutrinos Mixing with Muon Neutrinos in MINOS
• Interpreting IceCube 6-year HESE data as an evidence for hundred TeV decaying Dark Matter
• Cosmic Rays: Recent Progress and some Current Questions
• Efficient propagation of systematic uncertainties from calibration to analysis with the SnowStorm method in IceCube
• In-situ calibration of the single-photoelectron charge response of the IceCube photomultiplier tubes
• Transit Time and Charge Correlations of Single Photoelectron Events in R7081 PMTs
• Characterization of the Hamamatsu R11780 12 inch Photomultiplier Tube
• IceCube High Energy Starting Events at 7.5 Years -- New Measurements of Flux and Flavor
• IceCube Sterile Neutrino Searches
• The Physics Behind the CosmicWatch Desktop Muon Detectors
• The Effect of Hole Ice on the Propagation and Detection of Light in IceCube

Cited by in corpus (2)

• Searching for eV-scale sterile neutrinos with eight years of atmospheric neutrinos at the IceCube neutrino telescope
• Experimental indications of the 3+1 neutrino model with one sterile neutrino