Thesis Defense |
First, we take an SDA-based approach to modeling flavor evolution of solar neutrinos undergoing dynamics described by the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We incorporate measurements of solar neutrino flavor composition from the Borexino and Sudbury Neutrino Observatory experiments as a constraint for our model. This serves as a test case to establish the efficacy of SDA for neutrino oscillations. We find that this approach can reproduce the expected behavior from a typical forward integration method when the MSW effect is included in model dynamics. After verifying SDA can match established results, we use SDA to derive estimates of the solar neutrino mixing angle. Additionally, we constrain electron density inside the Sun and find a result consistent with the standard solar model.
We then turn to neutrinos in a core-collapse supernova (CCSN), where high neutrino density allows for complex behavior from neutrino-neutrino interactions. Despite their important role in CCSN dynamics, this complex nonlinear behavior makes collective CCSN neutrino oscillations difficult to model. We apply SDA to the task of modeling flavor evolution within the CCSN envelope, using a matter density profile and simulated measurements of neutrino flavor external to the CCSN. We demonstrate that SDA could be used with neutrino measurements to distinguish between multiple possible matter profiles, and to place a limit on fluctuations in matter density.