arXiv subjects

Maria Manuela Saez

Publications and source records attributed to Maria Manuela Saez.

5 recordsLinked to original sources

arXiv2025

Expected flavor composition of supernova neutrinos

We revisit the flavor composition of neutrinos from core-collapse supernovae (SN), focusing on robust predictions that are insensitive to the poorly known dynamics of collective flavor conversion in the inner core. Assuming that the many different trajectories and microscopic histories of neutrinos lead to decoherence of the ensemble at the boundary between the region of collective effects and the Mikheyev-Smirnov-Wolfenstein (MSW) dominated layers, we show that standard matter effects alone strongly constrain the electron-flavor fraction at Earth. For normal mass ordering (NO) we obtain $f_{ν_e}^{\rm NO}\lesssim 0.5$ at all times and energies, while for inverted ordering (IO), we predict $f_{ν_e}^{\rm IO}\simeq 1/3$, i.e.\ near flavor equipartition. Shock-wave propagation through the high (H) MSW resonance drives the system toward equipartition also in NO. In this way our framework links simple assumptions about decoherence and standard matter effects to robust expectations for the flavor evolution inside core-collapse supernovae. This contribution summarizes the main results of arXiv:2403.14762.

hep-ph↗

arXiv2025

Flavor composition of supernova neutrinos

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 $f_{ν_e}$, 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 ($f_{ν_e} \approx 1/3$). 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.

hep-ph↗

arXiv2024

Correlations and Distinguishability Challenges in Supernova Models: Insights from Future Neutrino Detectors

This paper explores core-collapse supernovae as crucial targets for neutrino telescopes, addressing uncertainties in their simulation results. We comprehensively analyze eighteen modern simulations and discriminate among supernova models using realistic detectors and interactions. A significant correlation between the total neutrino energy and cumulative counts, driven by massive lepton neutrinos and oscillations, is identified, particularly noticeable with the DUNE detector. Bayesian techniques indicate strong potential for model differentiation during a Galactic supernova event, with HK excelling in distinguishing models based on equation of state, progenitor mass, and mixing scheme.

astro-ph.HE↗

arXiv2023

Exploring Neutrino Mass Orderings through Supernova Neutrino Detection

Core-collapse supernovae (SNe) are one of the most powerful cosmic sources of neutrinos, with energies of several MeV. The emission of neutrinos and antineutrinos of all flavors carries away the gravitational binding energy of the compact remnant and drives its evolution from the hot initial to the cold final states. Detecting these neutrinos from Earth and analyzing the emitted signals present a unique opportunity to explore the neutrino mass ordering problem. This research outlines the detection of neutrinos from SNe and their relevance in understanding the neutrino mass ordering. The focus is on developing a model-independent analysis strategy, achieved by comparing distinct detection channels in large underground detectors. The objective is to identify potential indicators of mass ordering within the neutrino sector. Additionally, a thorough statistical analysis is performed on the anticipated neutrino signals for both mass orderings. Despite uncertainties in supernova explosion parameters, an exploration of the parameter space reveals an extensive array of models with significant sensitivity to differentiate between mass orderings. The assessment of various observables and their combinations underscores the potential of forthcoming supernova observations in addressing the neutrino mass ordering problem.

astro-ph.HE↗

arXiv2016

Effects of active-sterile neutrino mixing during primordial nucleosynthesis

In the present work, we discuss the effects of the inclusion of sterile-active neutrino oscillations during the production of primordial light-nuclei. We assume that the sterile neutrino mass-eigenstate might oscillate with the two lightest active neutrino mass- eigenstates, with mixing angles $ϕ_1$ and $ϕ_2$. We also allow a constant renormalization (represented by a parameter ($ζ$)) of the sterile neutrino occupation factor. Taking $ζ$ and the mixing angles as free parameters, we have computed distribution functions of active and sterile neutrinos and primordial abundances. Using observable data we set constrains in the free parameters of the model. It is found that the data on primordial abundances are consistent with small mixing angles and with a value of $ζ$ smaller than 0.65 at 3$σ$ level.

astro-ph.CO↗