Searching for Quantum Gravity with Neutrinos, Optical Module Beam Test at Fermilab and Hadronization Model studies for IceCube
Abstract
Neutrinos are elementary particles of nature, and they are composed of three flavours;
electron, muon, and tau neutrinos. Neutrino telescopes, such as the IceCube Neutrino
Observatory, detect high-energy neutrinos produced from cosmic ray interactions in the
atmosphere and distant astrophysical objects. Such high-energy neutrinos can be used as
a probe to search for violations of fundamental spacetime symmetries as new spacetime
structure can drive non-standard flavour mixings of neutrinos. Firstly, a search using
atmospherically produced neutrinos detected at IceCube is presented. This allows us to
set limits on higher-dimensional operators in this framework. Secondly, a search using veryhigh-
energy astrophysically produced neutrinos is presented, searching for modifications in
the measured astrophysical neutrino flavour composition for the very first time. Although
the current statistics and detector sensitivity allows for searches for only rather special
new physics effects, it is demonstrated that the sensitivity of this new approach reaches
for the first time the necessary precision to look for new physics within the Planck scale
expectation.
Future neutrino telescopes such as the IceCube-Upgrade will focus on oscillation physics
down to few GeV. Here, photomultiplier tubes (PMTs) are used to cover large volumes,
however instrumentation is relatively coarse, and particle identification (PID) is
done through the morphology of PMT hits. Here, the principle of pulse shape PID using
a single 10-inch hemispherical PMT is studied. The Fermilab Test Beam Facility MTest
beam line is used to demonstrate that with pulse shape PID, it is possible to distinguish
2 GeV electrons from 8 GeV pions, where the total charge deposition is 20 PE. Furthermore,
among the physics of hadronic systems in neutrino interactions, the hadronization
model controls multiplicities of final state hadrons. Here, the possibility of implementing
the pythia 8 program in the genie neutrino interaction generator is studied, showing
comparisons of pythia 8 predictions with neutrino-hadron multiplicity data from bubble
chamber experiments.
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Authors
Mandalia, ShiveshCollections
- Theses [3919]