Neutrinos and the Proposed India-based Neutrino Observatory

How the Sun shines has puzzled astronomers and biologists over the ages. The answer to this question led to a deeper understanding of an enigmatic particle, the neutrino, through the quantum mechanical phenomenon of neutrino oscillation. Neutrinos produced in various reactions change their type or 'flavor' as they propagate, and this requires them to possess a small but non-zero mass-they were earlier thought to be massless. The excitement in the area of studying neutrinos, about which we still know very little, led to the proposal for an India-based Neutrino Observatory (INO). We will review the physics of neutrinos, as well as the physics goals and current status of INO, in this article.