Into uncharted waters: the past, present, and future exploration of neutrino physics

Abstract

Despite decades of hints, beginning with the first solar neutrino experiment by Ray Davis and collaborators and the studies of atmospheric neutrinos by the Kamiokande II and IMB collaborations, the recent discoveries by the Super-Kamiokande and Sudbury Neutrino Observatory (SNO) collaborations have exceeded what were even the most optimistic expectations. We have suddenly discovered what we long suspected was true: neutrinos are more complex-and interesting-than the simple model we have used for twenty years or more. And unlike the rest of the Standard Model of particle physics which has been mapped in great detail, this new region which has opened up before us is by contrast completely unknown-we have entered uncharted waters, and the opportunities for exploration are greater than they have been for many decades. In this talk I will briefly outline both the historical background and the discoveries themselves, focusing on some of the technical problems that were solved along the way. I will then move to talk about future neutrino experiments, and some of the challenges they will bring.