Matter-Neutrino Resonance Above Merging Compact Objects

TL;DR

This paper investigates matter-neutrino resonance phenomena in neutrino emissions from accretion disks formed after neutron star or black hole mergers, revealing unique flavor transition behaviors due to antineutrino dominance.

Contribution

It introduces the concept of matter-neutrino resonance in merger disk neutrinos and provides numerical analysis of flavor transition conditions in this context.

Findings

Antineutrino dominance leads to new oscillation physics.

Large $ u_e$ flavor transition observed.

Conditions for resonance transition identified.

Abstract

Accretion disks arising from neutron star- neutron star mergers or black hole- neutron star mergers produce large numbers of neutrinos and antineutrinos. In contrast to other astrophysical scenarios, like supernovae, in mergers the antineutrinos outnumber the neutrinos. This antineutrino dominance gives neutrinos from merger disks the opportunity to exhibit new oscillation physics, specifically a matter-neutrino resonance. We explore this resonance, finding that consequences can be a large transition of $\nu_e$ to other flavors, while the $\bar{\nu}_e$s return to their initial state. We present numerical calculations of neutrinos from merger disks and compare with a single energy model. We explain both the basic features and the conditions for a transition.