New method for detecting fast neutrino flavor conversions in core-collapse supernova models with two-moment neutrino transport

Understand

Fast-pairwise neutrino oscillations potentially affect many aspects of core-collapse supernova (CCSN): the explosion mechanism, neutrino signals, and nucleosynthesis in the ejecta.

• This particular mode of collective neutrino oscillations has a deep connection to the angular structure of neutrinos in momentum space; for instance, the appearance of electron neutrinos lepton number (ELN) angular crossings in momentum space is a good indicator of occurrences of the flavor conversions.
• However, many multi-dimensional (multi-D) CCSN simulations are carried out with approximate neutrino transport (such as two-moment methods), which limits the access to the angular distributions of neutrinos, i.e., inhibits ELN-crossing searches.
• In this paper, we develop a new method of ELN-crossing search in these CCSN simulations.