Neutrino Fast Flavor Pendulum. Part 2: Collisional Damping

Abstract

In compact astrophysical objects, the neutrino density can be so high that neutrino-neutrino refraction can lead to fast flavor conversion of the kind ${\nu }_e{\bar{\nu }}_e\leftrightarrow {\nu }_x{\bar{\nu }}_x$ with $x=\mu ,\tau$, depending on the neutrino angle distribution. Previously, we have shown that in a homogeneous, axisymmetric two-flavor system, these collective solutions evolve in analogy to a gyroscopic pendulum. In flavor space, its deviation from the weak-interaction direction is quantified by a variable $\cos \vartheta$ that moves between $+1$ and $\cos {\vartheta }_{\min }$, the latter following from a linear mode analysis. As a next step, we include collisional damping of flavor coherence, assuming a common damping rate $\Gamma$ for all modes. Empirically we find that the damped pendular motion reaches an asymptotic level of pair conversion $f=A+(1-A)\cos {\vartheta }_{\min }$ (numerically $A\simeq 0.370$) that does not depend on details of the angular distribution (except for fixing $\cos {\vartheta }_{\min }$), the initial seed, nor $\Gamma$. On the other hand, even a small asymmetry between the neutrino and antineutrino damping rates strongly changes this picture and can even enable flavor instabilities in otherwise stable systems.

arXiv comment9 figures, 14 pages. Matches version published in Phys. Rev. D

References in corpus (39)

• Explosion Mechanisms of Core-Collapse Supernovae
• Collective Neutrino Oscillations
• Simulation of Coherent Non-Linear Neutrino Flavor Transformation in the Supernova Environment I: Correlated Neutrino Trajectories
• Self-induced conversion in dense neutrino gases: Pendulum in flavour space
• 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
• Linearized flavor-stability analysis of dense neutrino streams
• Neutrino oscillations in supernovae: angular moments and fast instabilities
• Self-induced decoherence in dense neutrino gases
• Non-Abelian Boltzmann Equation for Mixing and Decoherence
• Fast flavor conversions of supernova neutrinos: Classifying instabilities via dispersion relations
• Fast neutrino flavor instability and neutrino flavor lepton number crossings
• Fast Flavor Depolarization of Supernova Neutrinos
• Collisional triggering of fast flavor conversions of supernova neutrinos
• Neutrino Quantum Kinetics in Compact Objects
• Dynamic fast flavor oscillation waves in dense neutrino gases
• Fast flavor oscillations in dense neutrino media with collisions
• Collective fast neutrino flavor conversions in a 1D box: Initial condition and long-term evolution
• Fast neutrino flavor conversion: roles of dense matter and spectrum crossing
• Fast oscillations, collisionless relaxation, and spurious evolution of supernova neutrino flavor
• A change of direction in pairwise neutrino conversion physics: The effect of collisions
• Fast flavor conversions in supernovae: the rise of mu-tau neutrinos
• Neutrino Flavor Pendulum Reloaded: The Case of Fast Pairwise Conversion
• Neutrino Flavor Conversions in High-Density Astrophysical and Cosmological Environments
• Simulations of Fast Neutrino Flavor Conversions with Interactions in Inhomogeneous Media
• Normal-mode Analysis for Collective Neutrino Oscillations
• Collective Neutrino Flavor Instability Requires a Crossing
• Neutrino Fast Flavor Pendulum. Part 2: Collisional Damping
• Three flavor neutrino conversions in supernovae: Slow $\&$ Fast instabilities
• On the Occurrence of Crossings Between the Angular Distributions of Electron Neutrinos and Antineutrinos in the Supernova Core
• Neutrino propagation hinders fast pairwise flavor conversions
• Dynamics of fast neutrino flavor conversions with scattering effects: a detailed analysis
• The three flavor revolution in fast pairwise neutrino conversion
• Multi-Dimensional Solution of Fast Neutrino Conversions in Binary Neutron Star Merger Remnants
• Enhancement or damping of fast neutrino flavor conversions due to collisions
• Dispelling a myth on dense neutrino media: fast pairwise conversions depend on energy
• Supernova fast flavor conversions in 1+1D : Influence of mu-tau neutrinos
• Symmetry breaking induced by pairwise conversion of neutrinos in compact sources

Cited by in corpus (37)

• Fast Neutrino Flavor Conversion in Core-Collapse Supernovae: A Parametric Study in 1D Models
• Collisional flavor instabilities of supernova neutrinos
• Neutrino Fast Flavor Pendulum. Part 2: Collisional Damping
• Evaluating approximate asymptotic distributions for fast neutrino flavor conversions in a periodic 1D box
• Collisional flavor instability in dense neutrino gases
• Collision-induced flavor instability in dense neutrino gases with energy-dependent scattering
• Neutrinos and nucleosynthesis of elements
• A Systematic Study on the Resonance in Collisional Neutrino Flavor Instability
• Flavor solitons in dense neutrino gases
• Collisional and Fast Neutrino Flavor Instabilities in Two-dimensional Core-collapse Supernova Simulation with Boltzmann Neutrino Transport
• Universality of the Neutrino Collisional Flavor Instability in Core Collapse Supernovae
• Neutrino fast flavor oscillations with moments: linear stability analysis and application to neutron star mergers
• Fast neutrino flavor conversions in a supernova: Emergence, evolution, and effects
• Perturbing Fast Neutrino Flavor Conversion
• Collective neutrino oscillations and heavy-element nucleosynthesis in supernovae: exploring potential effects of many-body neutrino correlations
• Applications of Machine Learning to Detecting Fast Neutrino Flavor Instabilities in Core-Collapse Supernova and Neutron Star Merger Models
• Theory of neutrino slow flavor evolution. Part I. Homogeneous medium
• Flavor conversions with energy-dependent neutrino emission and absorption
• Neutrino many-body correlations
• Symmetry and bipolar motion in collective neutrino flavor oscillations
• Collective flavor conversions are interactions of neutrinos with quantized flavor waves
• Fast Flavor Pendulum: Instability Condition
• Spectral diversity in collisional neutrino-flavor conversion: flavor equipartition or swap
• Quasi-steady evolution of fast neutrino-flavor conversions
• Subgrid modeling of neutrino oscillations in astrophysics
• Flavor Equilibration of Supernova Neutrinos: Exploring the Dynamics of Slow Modes
• Supernova Neutrinos: flavour conversion mechanisms and new physics scenarios
• Muon-induced collisional flavor instability in core-collapse supernova
• Thermodynamics of oscillating neutrinos
• Neutrino quantum kinetics in two spatial dimensions
• Predicting the outcome of collisional neutrino flavor conversion
• Symmetry breaking due to multi-angle matter-neutrino resonance in neutron star merger remnants
• Steady state of fast-oscillating neutrinos in an inhomogeneous medium
• Systematic local simulations of fast neutrino flavor conversions with scattering effects
• Sufficient and Necessary Conditions for Collective Neutrino Instability: Fast, Slow, and Mixed
• Neutrino flavor instabilities in neutron star mergers with moment transport: Slow, fast, and collisional modes
• Approximate Energy-Integration Method for Identifying Collisional Neutrino Flavor Instabilities