Abstract:

Exciting results from the Sudbury Neutrino Observatory (SNO) in the last few years have demonstrated that neutrinos produced in the sun change flavor prior to reaching the earth. Theoretical explanations for solar neutrino flavor change invoke matter-enhanced oscillations in the interior of the sun (the MSW effect). The same matter effects could alter the flavor composition of neutrinos that traverse the earth before reaching the SNO detector. I will describe this effect and present details of a day-night analysis of solar neutrino flavor in the second phase of the SNO experiment. I will discuss the possible implications of future SNO day-night results for testing MSW physics and constraining fundamental neutrino parameters.