Supernova Relic Neutrino Search at Super-Kamiokande

TLDR: A new Super-Kamiokande search for supernova relic neutrinos was conducted using 2853 live days of data as mentioned in this paper, and the results showed that the neutrino flux was between 2.8 and 3.3 MeV.

Abstract: A new Super-Kamiokande search for supernova relic neutrinos was conducted using 2853 live days of data. Sensitivity is now greatly improved compared to the 2003 Super-Kamiokande result, which placed a flux limit near many theoretical predictions. This more detailed analysis includes a variety of improvements such as increased efficiency, a lower energy threshold, and an expanded data set. New combined upper limits on supernova relic neutrino flux are between 2.8 and $3.1{\overline{\ensuremath{\nu}}}_{e}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}g16\text{ }\text{ }\mathrm{MeV}$ total positron energy (17.3 MeV ${\mathrm{E}}_{\ensuremath{\nu}}$).