The diffuse supernova neutrino background: Expectations and uncertainties derived from SN1987A

TL;DR

This paper estimates the expected detection rate of the diffuse supernova neutrino background using current and improved detector configurations, highlighting the dominant uncertainties from supernova emission models.

Contribution

It provides a detailed calculation of the expected neutrino background signal and its uncertainties based on SN1987A data, considering detector improvements like gadolinium loading.

Findings

Expected signal rate ranges from 0.3 to 0.9 events/year without gadolinium.

Gadolinium loading increases the expected rate to 1.1 to 2.9 events/year.

Astrophysical uncertainties in supernova emission dominate the total uncertainty.

Abstract

Context: The detection of the diffuse supernova neutrino background may be imminent, but theoretical predictions are affected by substantial uncertainties. AIMS. We calculate the signal and its uncertainty with the present configuration of Super-Kamiokande and consider the possibility of lowering the threshold by means of gadolinium loading. Methods: We model neutrino emission following the analysis of SN1987A by Pagliaroli and collaborators 2009 and use the number of expected events in the neutrino detector as a free parameter of the fit. The best-fit value of this parameter and its error are evaluated by means of standard maximum likelihood procedures, taking into account properly the correlations. Results: The uncertainties in the astrophysics of the emission dominates the total uncertainty in the expected signal rate, which conservatively ranges from 0.3 to 0.9 events per year and from 1.1 to 2.9 with gadolinium.