Supernova Neutrinos: Production, Oscillations and Detection (1508.00785v2)

Abstract: Neutrinos play a crucial role in the collapse and explosion of massive stars, governing the infall dynamics of the stellar core, triggering and fueling the explosion and driving the cooling and deleptonization of the newly formed neutron star. Due to their role neutrinos carry information from the heart of the explosion and, due to their weakly interacting nature, offer the only direct probe of the dynamics and thermodynamics at the center of a supernova. In this paper, we review the present status of modelling the neutrino physics and signal formation in collapsing and exploding stars. We assess the capability of current and planned large underground neutrino detectors to yield faithful information of the time and flavor dependent neutrino signal from a future Galactic supernova. We show how the observable neutrino burst would provide a benchmark for fundamental supernova physics with unprecedented richness of detail. Exploiting the treasure of the measured neutrino events requires a careful discrimination of source-generated properties from signal features that originate on the way to the detector. As for the latter, we discuss self-induced flavor conversions associated with neutrino-neutrino interactions that occur in the deepest stellar regions; matter effects that modify the pattern of flavor conversions in the dynamical stellar envelope; neutrino-oscillation signatures that result from structural features associated with the shock-wave propagation as well as turbulent mass motions in post-shock layers. Finally, we highlight our current understanding of the formation of the diffuse supernova neutrino background and we analyse the perspectives for a detection of this relic signal that integrates the contributions from all past core-collapse supernovae in the Universe.

• The paper presents detailed numerical simulations of neutrino production during core-collapse, highlighting distinct phases such as neutronization, accretion, and cooling.
• The paper analyzes neutrino oscillations using the MSW effect and density matrix formalism to model self-induced flavor conversions in dense environments.
• The paper underscores the need for advanced detection technologies to capture diverse neutrino signals and constrain key particle physics parameters.

Overview of Supernova Neutrinos: Production, Oscillations, and Detection

This paper dives deep into the various theoretical and observational aspects of supernova neutrinos, underlining their significance in the paper of stellar collapses and explosions. The authors present a comprehensive review focused on the production of neutrinos in the core-collapse of massive stars. Neutrinos are shown to play a pivotal role in the gravitational collapse, initiating and fueling supernovae explosions, and they serve as a crucial channel for the cooling of the resultant neutron star.

The discussion begins with an exploration of the mechanisms of neutrino production within the dense cores of massive stars. These particles are emitted during the collapse phase and through subsequent interactions in the proto-neutron star. The authors address the fundamental properties of neutrinos and their emission characteristics based on the stellar mass and the equation of state of dense matter. Special attention is given to the different phases of neutrino emission, such as the neutronization burst, accretion phase, and cooling phase, each described with detailed numerical simulations illustrating different stellar progenitors.

The paper also explores neutrino oscillations, emphasizing the impact of self-induced flavor conversions which are particularly significant near the core where neutrino densities are tremendously high. The authors analyze the interaction of neutrinos with matter (MSW effect), and how these interactions can influence the observable neutrino burst depending on the mass hierarchy and the oscillation parameters. The complex dynamics of flavor evolution, including the effect of neutrino-neutrino interactions and collective oscillations, are described through the mathematical framework of neutrino density matrices.

Additionally, the paper explains the implications of neutrino oscillations on supernova detection techniques and the predictions for large underground detectors. Such detectors could potentially witness the neutrino burst of a future supernova within our galaxy, offering rich data to test the current models of core-collapse physics and neutrino properties.

In terms of theoretical significance, the authors highlight the profound implications supernova neutrinos have on constraining various parameters of particle physics, such as mass hierarchies and potential new physics scenarios involving sterile neutrinos or exotic interactions. The detection of supernova neutrinos can offer insights into these physics questions while providing information on the astrophysical processes occurring during supernova explosions.

Practically, this research underscores the crucial need for advanced detection capabilities and improved simulation models. The paper suggests that next-generation detectors with enhanced resolution and sensitivity to all neutrino flavors are essential for capturing comprehensive data on supernova neutrinos, which could further refine our understanding of both neutrino physics and astrophysical phenomena. The complex interplay of self-interactions, oscillations, and external applications as discussed presents future directions in modeling and observational techniques that align with the theoretical framework established in this paper.