Supernova relic neutrino search at super-Kamiokande

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 $3.1{\overline{\ensuremath{\nu}}}_{e}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}>16\text{ }\text{ }\mathrm{MeV}$ total positron energy (17.3 MeV ${\mathrm{E}}_{\ensuremath{\nu}}$).