Sierra Wilde successfully defends thesis, "Rare Event Searches in Neutrino Detectors"
On August 31, Sierra Wilde successfully defended the thesis, “Rare Event Searches in Neutrino Detectors” (advisor David Moore).
Wilde explained, “Neutrinos are fundamental particles that are very elusive because they rarely interact with matter. I have worked on two different experiments exploring different properties of the neutrino. nEXO is a future experiment searching for a rare nuclear decay called neutrinoless double beta decay. If discovered, it would prove that neutrinos are their own antiparticle and also would have implications on cosmological questions related to why there is more matter than antimatter in the Universe. I worked on several projects to aid the design and analysis of the detector, most of which involved the photodetector. I performed studies to characterize the devices nEXO plans on using to detect photons. I also ran simulations and developed analysis pipelines to better reject radioactive backgrounds that could interfere with a neutrinoless double beta decay signal.”
Wilde continued, “The second experiment I worked on was BeEST, which is an experiment searching for sterile neutrinos. Sterile neutrinos are additional types of neutrinos that would not interact like the standard, active neutrinos. If sterile neutrinos exist, they can start to provide answers about how neutrinos acquire their mass and may even be a dark matter candidate. I did an analysis using BeEST’s data to search for a different particle that could also be a dark matter candidate.”
Wilde will next be a Linus Pauling Distinguished Postdoctoral Fellow at Pacific Northwest National Laboratory (PNNL).
Thesis Abstract: Nearly 100 years after Pauli’s initial theory, particle physicists still have major unanswered questions about the fundamental properties of the neutrino. These elusive particles hold many secrets and studying them gives us opportunities to discover Beyond the Standard Model (BSM) physics. The detection of neutrinoless double beta decay will be proof that neutrinos are Majorana fermions and will start to answer questions about the origins of matter. Discovering sterile neutrinos could help identify the nature of dark matter or explain the neutrino’s mass scale. nEXO and the BeEST are both experiments that are designed to search for answers to questions about the fundamental properties of the neutrino through precision measurements of β decay. I will describe improvements to nEXO’s photodetector response analysis and the search for a new BSM physics particle in the BeEST.
Thesis committee: David Moore, Reina Maruyama, Laura Newburgh, Ian Moult, and Erica Caden (Snolab)