Turbulence effects on supernova neutrinos

Abstract

Multidimensional core-collapse supernova simulations exhibit turbulence of large amplitude and over large scales. As neutrinos pass through the supernova mantle the turbulence is expected to modify their evolution compared to the case where the explosion is free of turbulence. In this paper we study this turbulence effect upon the neutrinos modeling the turbulence expected from multidimensional simulations by adding matter density fluctuations to density profiles taken from one-dimensional hydrodynamical simulations. We investigate the impact upon the supernova neutrino transition probabilities as a function of the neutrino mixing angle ${\ensuremath{\theta}}_{13}$ and turbulence amplitude. In the high resonant channel and with large ${\ensuremath{\theta}}_{13}$ values we find that turbulence is effectively two flavor for fluctuation amplitudes $\ensuremath{\lesssim}1%$ and have identified a new effect due to the combination of turbulence and multiple high resonances that leads to a sensitivity to fluctuations amplitudes as small as $\ensuremath{\sim}0.001%$. At small values of ${\ensuremath{\theta}}_{13}$, beyond the range achievable in Earth based experiments, we find that turbulence leads to new flavor transient effects in the channel where the Mikheev-Smirnov-Wolfenstein high resonance occurs. Finally, we investigate large amplitude fluctuations which lead to three-flavor effects due to broken high-low factorization and significant nonresonant transitions and identify two nonresonant turbulence effects, one depending on the ${\ensuremath{\theta}}_{13}$, and the other independent of this angle and due to the low Mikheev-Smirnov-Wolfenstein resonance.