A search for the relic neutrinos from all past core-collapse supernovae was conducted using 1496 days of data from the Super-Kamiokande detector. This analysis looked for electron-type antineutrinos that had produced a positron with an energy greater than 18 MeV. In the absence of a signal, 90% C.L. upper limits on the total flux were set for several theoretical models; these limits ranged from 20 to $130\text{ }{\overline{\ensuremath{\nu}}}_{e}\text{ }{\mathrm{c}\mathrm{m}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$. Additionally, an upper bound of $1.2\text{ }{\overline{\ensuremath{\nu}}}_{e}\text{ }{\mathrm{c}\mathrm{m}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ was set for the supernova relic neutrino flux in the energy region ${E}_{\ensuremath{\nu}}>19.3\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}$.
Search for Supernova Relic Neutrinos at Super-Kamiokande | Litlas
