Neutrino Flavor Evolution in Binary Neutron Star Merger Remnants

Understand

We study the neutrino flavor evolution in the neutrino-driven wind from a binary neutron star merger remnant consisting of a massive neutron star surrounded by an accretion disk.

• With the neutrino emission characteristics and the hydrodynamical profile of the remnant consistently extracted from a three-dimensional simulation, we compute the flavor evolution by taking into account neutrino coherent forward scattering off ordinary matter and neutrinos themselves.
• We employ a "single-trajectory" approach to investigate the dependence of the flavor evolution on the neutrino emission location and angle.
• We also show that the flavor conversion in the merger remnant can affect the (anti-)neutrino absorption rates on free nucleons and may thus impact the $r$-process nucleosynthesis in the wind.