“Coherence and Decoherence in Neutrino Oscillations”
Neutrino oscillations provide a long baseline interferometer with which to test the principles of quantum physics and study the quantum mechanical nature of spacetime. Even in the standard paradigm, neutrino oscillations cannot continue for an infinite distance – neutrino mass states will eventually separate due to their different group velocities, prohibiting further interference. Predicting the baseline over which such coherence-loss effects will occur requires an understanding of the width of the neutrino wave function at production. While this quantity is calculable in principle, disagreement about the relevant distance scales remains widespread. I will review the current status of this problem both experimentally and theoretically, and discuss both standard- and non-standard sources of coherence loss in neutrino oscillations. The talk will cover recent experimental results from BeEST and IceCube and their interpretations, as well as attempts to explain the gallium anomaly through anomalous decoherence.