Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminars |
self-interactions (νSI) are allowed by laboratory, cosmology, and
astrophysics data, and are frequently invoked to explain anomalies. In
this talk, I will briefly review the current probes of νSI. I will
then discuss the potential interplay between νSI and supernova
neutrinos. For the high neutrino densities within core-collapse
supernovae, νSI could be important, but robust observables have been
lacking. We show that νSI makes supernova neutrinos form a tightly
coupled fluid that expands under relativistic hydrodynamics. The
outflow becomes either a burst or a steady-state wind; which occurs
here is uncertain. Though the diffusive environment where neutrinos
are produced may make a wind more likely, further work is needed to
determine when each case is realized. In the burst-outflow case, νSI
increases the duration of the neutrino signal, and even a simple
analysis of SN 1987A data has powerful sensitivity. For the
wind-outflow case, we outline several promising ideas that may lead to
new observables. Combined, these results are important steps towards
solving the 35-year-old puzzle of how νSI impacts supernovae.