T-16 Nuclear Physics Group

Neutrino is the only particle that has been experimentally proven to possess properties different from what have been predicted by the standard particle physics model. Because neutrinos interact only weakly with matter, they can escape much more easily from the centers of stars or stellar objects than other particles do. Therefore, extraterrestrial neutrinos, once detected, can be used as direct probes to the physical conditions deep side the astrophysical sites of interest. However, the energy spectra of neutrinos that we observed on the Earth are different from those at neutrino emission points/surfaces because of a quantum phenomenon known as "neutrino oscillations". In this talk I will focus on "collective neutrino oscillations" in core-collapse supernovae, a macroscopic, quantum phenomenon driven purely by weak interaction. A full understanding of this phenomenon is critical in analysis of neutrino signals from future galactic supernovae. This analysis may provide a unique way to determine some neutrino properties that are difficult to measure otherwise.