Search for Supernova Relic Neutrinos at Super-Kamiokande

TL;DR

This study searched for supernova relic neutrinos using Super-Kamiokande data, setting upper limits on their flux and providing constraints on supernova models, but did not detect a signal.

Contribution

First search for supernova relic neutrinos with extensive Super-Kamiokande data, establishing new upper limits on neutrino fluxes in the process.

Findings

No significant neutrino signal detected.

Set upper limits on neutrino flux ranging from 20 to 130 nu_e bar cm^-2 s^-1.

Established an upper bound of 1.2 nu_e bar cm^-2 s^-1 for E_nu > 19.3 MeV.

Abstract

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 anti-neutrinos 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 nu_e bar cm^-2 s^-1. Additionally, an upper bound of 1.2 nu_e bar cm^-2 s^-1 was set for the supernova relic neutrino flux in the energy region E_nu > 19.3 MeV.