Many experiments are currently exploring the phenomenon of neutrino flavor transformation. Data from these experiments, such as data from atmospheric neutrinos measured at SuperKamiokande, is interpreted as indirect evidence for neutrino mass. This interpretation requires new physics which goes beyond the standard model of particle physics. A model involving extra dimensions will be discussed as an example of a scenario which can produce light neutrino masses.
Neutrinos also play an important role in astrophysics.
Since most of the energy of a supernova is released in the form of neutrinos, they are crucial for understanding this environment. In particular, neutrino scattering and flavor transformation have a significant impact on supernova nucleosynthesis. Although neutrino capture is detrimental, neutrino oscillation scenarios could provide a viable environment for the formation of heavy elements.