Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)

Graduate Group

Physics & Astronomy

First Advisor

Joshua R. Klein


The Sudbury Neutrino Observatory has demonstrated that the apparent deficit in solar neutrinos observed on Earth is due to matter-enhanced flavor transitions, and provided precision measurements of the relevant oscillation parameters. The low backgrounds and large, spectral charged-current $\nu_e-d$ cross section that enabled these measurements also give SNO unique sensitivity to two yet-unobserved neutrino signals of great interest: the $hep$ solar neutrino flux and the diffuse supernova neutrino background (DSNB).

This work presents a joint analysis of all three running configurations of the SNO experiment in order to improve constraints on the $hep$ and DSNB $\nu_e$ fluxes. The crucial uncertainties in the energy response and atmospheric neutrino background, as well as the event selection criteria, are reevaluated. Two analysis approaches are taken, a single-bin counting analysis ($hep$ and DSNB) and multidimensional signal extraction fit ($hep$), using a random sample representing 1/3 of the total SNO data. These searches are the most sensitive to date for these important signals, and will improve further when the full dataset is analyzed.

The SNO+ liquid scintillator experiment is a successor to SNO primarily concerned with a search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{130}$Te. The modifications to the SNO detector in preparation for SNO+ and an analysis of the $0\nu\beta\beta$ sensitivity of this upcoming experiment will also be presented in this work. SNO+ will be the first experiment to load Te into liquid scintillator, and is expected to achieve world-class sensitivity in an initial phase commencing in 2017, with significantly improved sensitivity in an upgraded configuration to follow using much higher Te target mass.

Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Included in

Physics Commons