ORCID Identifier(s)

0000-0003-4957-565X

Graduation Semester and Year

2022

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Physics and Applied Physics

Department

Physics

First Advisor

Ben Jones

Abstract

The IceCube Neutrino Observatory, a gigaton-scale ice Cherenkov detector located deep within the Antarctic glacier, has detected hundreds of thousands of atmospheric neutrinos at energies from a few GeV to 100 TeV. Above 100 GeV, where ordinary oscillation effects become vanishingly small, this data sample is particularly sensitive to a wide range of beyond-standard-model (BSM) neutrino oscillation mechanisms. This thesis presents two searches for such BSM physics: flavor-changing nonstandard neutrino interactions (NSI) and neutrino oscillation decoherence (decoherence). The first analysis constrains the mu-tau flavor-changing NSI parameter with eight years of IceCube atmospheric neutrino data ranging from 500 GeV to 1 TeV. No evidence is found for the NSI parameter with a p-value of 25.2%, and the constraints of this analysis improve on the previous leading constraints by a factor of two. The second analysis probes for signals of neutrino oscillation decoherence through interactions with spacetime foam. Two models of spacetime foam are tested at four different values of energy power law. No evidence is found for neutrino decoherence, and constraints are improved in comparison with previous leading measurements with the improvement increasing exponentially with the decoherence power law index. These measurements, taken together, represent new leading results on priority fronts in the search for new physics and demonstrate IceCube's unique sensitivity to high-energy BSM physics through experimental statements on the nature of both sub-dominant neutrino interactions and the quantum behavior of spacetime.

Keywords

Neutrino, Non-standard interactions, Decoherence, Quantum gravity, Quantum foam, IceCube

Disciplines

Physical Sciences and Mathematics | Physics

Comments

Degree granted by The University of Texas at Arlington

Included in

Physics Commons

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