The neutrino spectral split in core-collapse supernovae: a magnetic resonance phenomenon

Understand

A variety of neutrino flavour conversion phenomena occur in core-collapse supernova, due to the large neutrino density close to the neutrinosphere, and the importance of the neutrino-neutrino interaction.

• Three different regimes have been identified so far, usually called the synchronization, the bipolar oscillations and the spectral split.
• Using the formalism of polarization vectors, within two-flavours, we focus on the spectral split phenomenon and we show for the first time that the physical mechanism underlying the neutrino spectral split is a magnetic resonance phenomenon.
• In particular, we show that the precession frequencies fulfill the magnetic resonance conditions.