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 5.1Β±0.4β2.0β2.7+0.0+0.5βcm2Β sβ1 at SK employing Gd-tagging, or 3.6Β±0.3β1.6β1.9+0.0+0.8β
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
3Ο detection by βΌ2030 with SK-Gd and a 5Ο detection by
βΌ2035 with a joint SK-Gd/JUNO analysis, but background reduction remains
crucial.Comment: 19 pages, 9 figures, 3+2 tables. Comments welcom