Symmetry breaking due to multi-angle matter-neutrino resonance in neutron star merger remnants

Abstract

Neutron star merger remnants are unique sites for exploring neutrino flavor conversion in dense media. Because of the natural excess of ${\bar{\nu }}_e$ over ${\nu }_e$, the neutrino-neutrino potential can cancel the matter potential, giving rise to matter-neutrino resonant flavor conversion. Under the assumption of two (anti)neutrino flavors and spatial homogeneity, we solve the neutrino quantum kinetic equations to investigate the occurrence of the matter-neutrino resonance within a multi-angle framework. We find that isotropy is broken spontaneously, regardless of the mass ordering. Relying on a hydrodynamical simulation of a binary neutron star merger remnant with a black hole of $3M_{\odot }$ and an accretion torus of $0.3M_{\odot }$, we find that complete flavor conversion caused by the matter-neutrino resonance is unlikely, although the matter and neutrino potentials cancel at various locations above the disk. Importantly, the matter-neutrino resonant flavor conversion crucially depends on the shape of the neutrino angular distributions. Our findings suggest that an accurate modeling of the neutrino angular distributions is necessary to understand flavor conversion physics in merger remnants, its implications on the disk physics and synthesis of the elements heavier than iron.

31 pages, 18 figures. Minor changes, matches version accepted for publication in JCAP. Supplemental material: https://sid.erda.dk/share_redirect/e2zTyjhG3B/index.html

References in corpus (25)

• Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers
• Kilonovae
• Simulation of Coherent Non-Linear Neutrino Flavor Transformation in the Supernova Environment I: Correlated Neutrino Trajectories
• Collective neutrino flavor transitions in supernovae and the role of trajectory averaging
• Fast Pairwise Conversion of Supernova Neutrinos: A Dispersion-Relation Approach
• New Developments in Flavor Evolution of a Dense Neutrino Gas
• Imprints of neutrino-pair flavor conversions on nucleosynthesis in ejecta from neutron-star merger remnants
• Neutrino Fast Flavor Conversions in Neutron-star Post-Merger Accretion Disks
• Fast neutrino flavor instability and neutrino flavor lepton number crossings
• Fast neutrino flavor conversion, ejecta properties, and nucleosynthesis in newly-formed hypermassive remnants of neutron-star mergers
• Matter Neutrino Resonance Transitions above a Neutron Star Merger Remnant
• Neutrino Flavor Pendulum Reloaded: The Case of Fast Pairwise Conversion
• The Fast Flavor Instability in Hypermassive Neutron Star Disk Outflows
• Neutrino Fast Flavor Pendulum. Part 2: Collisional Damping
• Collisional instabilities of neutrinos and their interplay with fast flavor conversion in compact objects
• Neutrino Flavor Evolution in Binary Neutron Star Merger Remnants
• Collisional flavor instability in dense neutrino gases
• Spurious instabilities in multiangle simulations of collective flavor conversion
• Evaluating Approximate Flavor Instability Metrics in Neutron Star Mergers
• Multi-Dimensional Solution of Fast Neutrino Conversions in Binary Neutron Star Merger Remnants
• Neutrino Flavor Conversion, Advection, and Collisions: Towards the Full Solution
• Neutrino Decoupling Is Altered by Flavor Conversion
• Symmetry breaking induced by pairwise conversion of neutrinos in compact sources
• Effect of collisions on neutrino flavor inhomogeneity in a dense neutrino gas
• Resonant Production of Light Sterile Neutrinos in Compact Binary Merger Remnants

Cited by in corpus (4)

• Neutrinos from explosive transients at the dawn of multi-messenger astronomy
• Flavor Equilibration of Supernova Neutrinos: Exploring the Dynamics of Slow Modes
• Neutrino flavor instabilities in neutron star mergers with moment transport: Slow, fast, and collisional modes
• Neutrinos in colliding neutron stars and black holes