Flavor composition of supernova neutrinos

Abstract

Predicting the flavor composition of neutrinos from supernovae is a challenging task, primarily due to the high neutrino densities at their core. In such an environment, neutrino self-interactions give rise to collective effects that have dramatic yet poorly understood consequences for their flavor evolution. In this paper, however, we show that standard matter effects in the outer layers of supernovae can significantly constrain the flavor composition of the neutrino flux. We assume that, since a large number of neutrinos undergo different evolutions within the core, their state upon entering the MSW-dominated region is affected by decoherence. This assumption simplifies the problem and suggests that the fraction of neutrinos with electron flavor reaching Earth, denoted as $f_{{\nu }_e}$, is constrained to be less than $0.5$ for all energies throughout the emission phase in the case of normal mass ordering. In contrast, for inverted mass ordering, we anticipate neutrinos arriving in near flavor equipartition ($f_{{\nu }_e}\approx 1/3$). These predictions, and consequently their underlying assumptions, could be tested by future observations and may provide valuable insights into the properties of neutrino fluxes emerging from supernovae.

7 pages + references, 2 figures. Matches published version

References in corpus (23)

• 2020 Global reassessment of the neutrino oscillation picture
• Collective Neutrino Oscillations
• Identifying the neutrino mass spectrum from a supernova neutrino burst
• Speed-up of neutrino transformations in a supernova environment
• Fast Pairwise Conversion of Supernova Neutrinos: A Dispersion-Relation Approach
• Collective neutrino flavor conversion: Recent developments
• New Developments in Flavor Evolution of a Dense Neutrino Gas
• Neutrino cloud instabilities just above the neutrino sphere of a supernova
• The multi-angle instability in dense neutrino systems
• Self-induced neutrino flavor conversion without flavor mixing
• What can be learned from a future supernova neutrino detection?
• Neutrino signatures of supernova shock and reverse shock propagation
• Probing the neutrino mass hierarchy with the rise time of a supernova burst
• Fast Neutrino Flavor Conversions can Help and Hinder Neutrino-Driven Explosions
• Fast Neutrino Flavor Conversion in Core-Collapse Supernovae: A Parametric Study in 1D Models
• Roles of fast neutrino-flavor conversion on the neutrino-heating mechanism of core-collapse supernova
• Supernova Simulations Confront SN 1987A Neutrinos
• Phase effects in neutrino conversions during a supernova shock wave
• Supernova neutrinos: difference of nu_mu - nu_tau fluxes and conversion effects
• Liouville equations for neutrino distribution matrices
• Identifying neutrinos and antineutrinos in neutral-current scattering reactions
• Exploiting a future galactic supernova to probe neutrino magnetic moments
• New Resonances of Supernova Neutrinos in Twisting Magnetic Fields

Cited by in corpus (3)

• Towards First Detection of the Solar MSW Transition With JUNO
• Supernova $\nu$ flavour conversions in DUNE: the slow, the fast and the standard
• Cosmic Overture Echoed in a Stellar Final Act: Implications of Nanohertz Gravitational Waves for Core Collapse Supernova Neutrinos