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Neutrino Oscillations in Astrophysics

A survey of the theory of neutrino oscillations in dense matter and neutrino
backgrounds is presented. We discuss collective neutrino systems using the gyroscopic
pendulum analogy and describe the motion that results from self-induced
parametric resonances. The effects of dense matter on the
flavour oscillations
of neutrinos are also detailed. This theory is applied to the case of continuous
supernova neutrino spectra and explanations of the spectral swapping behaviour
seen in numerical studies are summarized.
The results of numerical simulations of supernova oscillations in turbulent
supernova backgrounds are presented and discussed. We study the motion of two
example supernova neutrino spectra and examine the differences in the dynamics
and
flavour evolution that results from adding turbulent
fluctuations to the
supernova matter background. We also investigate the effect that
fluctuations
in the neutrino density can have on the oscillation behaviour. We find that in
general the final neutrino spectra emerging from the inner supernova regions
are quite robust to
fluctuations in the backgrounds in our model, while the
intermediate dynamics can be very strongly altered. Some significant changes
in the final spectra are also found to occur when the neutrino background density
fluctuations are large.
We give a detailed review of the resonant matter effects that determine the
survival probabilities of atmospheric muon neutrinos. The differences between
various Earth density models are described, and these models are then used to
predict the flux of muon-type neutrino events in the Deep Core extension to the
IceCube detector. We use recent results from the detector collaboration and
build on previous work which considered the sensitivity of the detector to the
mass hierarchy, and show that uncertainties in the Earth's density can have a
significant influence on the event rates.

Identiferoai:union.ndltd.org:canterbury.ac.nz/oai:ir.canterbury.ac.nz:10092/4935
Date January 2010
CreatorsReid, Giles Adrian
PublisherUniversity of Canterbury. Physics and Astronomy
Source SetsUniversity of Canterbury
LanguageEnglish
Detected LanguageEnglish
TypeElectronic thesis or dissertation, Text
RightsCopyright Giles Adrian Reid, http://library.canterbury.ac.nz/thesis/etheses_copyright.shtml
RelationNZCU

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