Diffuse supernova neutrino background with up-to-date star formation rate measurements and long-term multidimensional supernova simulations

TL;DR

This paper refines predictions for the diffuse supernova neutrino background by integrating recent star formation data, advanced supernova simulations, and failed supernova models, estimating detection prospects for upcoming neutrino observatories.

Contribution

It combines updated star formation rates, multidimensional supernova simulations, and failed supernova models to improve DSNB flux predictions and detection time estimates.

Findings

Predicted DSNB flux at SK-Gd: 5.1 ± 0.4 cm^-2 s^-1

Expected detection: 3σ by ~2030, 5σ by ~2035 with SK-Gd/JUNO

Uncertainties dominated by star formation rates and supernova models

Abstract

The sensitivity of current and future neutrino detectors like Super-Kamiokande (SK), JUNO, Hyper-Kamiokande (HK), and DUNE is expected to allow for the detection of the diffuse supernova neutrino background (DSNB). However, the DSNB model ingredients like the core-collapse supernova (CCSN) rate, neutrino emission spectra, and the fraction of failed supernovae are not precisely known. We quantify the uncertainty on each of these ingredients by (i) compiling a large database of recent star formation rate density measurements, (ii) combining neutrino emission from long-term axisymmetric CCSNe simulations and strategies for estimating the emission from the protoneutron star cooling phase, and (iii) assuming different models of failed supernovae. Finally, we calculate the fluxes and event rates at multiple experiments and perform a simplified statistical estimate of the time required to significantly detect the DSNB at SK with the gadolinium upgrade and JUNO. Our fiducial model predicts a flux of $5.1\pm0.4^{+0.0+0.5}_{-2.0-2.7}\,{\rm cm^2~s^{-1}}$ at SK employing Gd-tagging, or $3.6\pm0.3^{+0.0+0.8}_{-1.6-1.9}$ events per year, where the errors represent our uncertainty from star formation rate density measurements, uncertainty in neutrino emission, and uncertainty in the failed-supernova scenario. In this fiducial calculation, we could see a $3\sigma$ detection by $\sim2030$ with SK-Gd and a $5\sigma$ detection by $\sim2035$ with a joint SK-Gd/JUNO analysis, but background reduction remains crucial.