Bayesian Inference of Supernova Neutrino Spectra with Multiple Detectors

TL;DR

This paper develops a Bayesian framework combining multiple neutrino detection channels to accurately infer supernova neutrino spectra, offering potential insights into neutrino properties and the neutrino mass hierarchy.

Contribution

It introduces a multi-channel Bayesian inference method for supernova neutrino spectra, incorporating data from various detectors to improve spectral parameter estimation and hierarchy sensitivity.

Findings

Achieves a few percent precision on spectral parameters for most neutrino flavors.

Identifies correlation patterns sensitive to neutrino mass hierarchy.

Provides a new approach for supernova neutrino analysis using combined detector data.

Abstract

We implement the Bayesian inference to retrieve energy spectra of all neutrinos from a galactic core-collapse supernova (CCSN). To achieve high statistics and full sensitivity to all flavours of neutrinos, we adopt a combination of several reaction channels from different large-scale neutrino observatories, namely inverse beta decay on proton and elastic scattering on electron from Hyper-Kamiokande (Hyper-K), charged current absorption on Argon from Deep Underground Neutrino Experiment (DUNE) and coherent elastic scattering on Lead from RES-NOVA. Assuming no neutrino oscillation or specific oscillation models, we obtain mock data for each channel through Poisson processes with the predictions, for a typical source distance of 10 kpc in our Galaxy, and then evaluate the probability distributions for all spectral parameters of theoretical neutrino spectrum model with Bayes' theorem. Although the results for either the electron-neutrinos or electron-antineutrinos reserve relatively large uncertainties (according to the neutrino mass hierarchy), a precision of a few percent (i.e., $\pm 1 \% \sim \pm 4 \%$ at a credible interval of $2 \sigma$) is achieved for primary spectral parameters (e.g., mean energy and total emitted energy) of other neutrino species. Moreover, the correlation coefficients between different parameters are computed as well and interesting patterns are found. Especially, the mixing-induced correlations are sensitive to the neutrino mass hierarchy, which potentially makes it a brand new probe to determine the neutrino mass hierarchy in the detection of galactic supernova neutrinos. Finally, we discuss the origin of such correlation patterns and perspectives for further improvement on our results.