Search for Neutrinos in Super-Kamiokande associated with Gravitational Wave Events GW150914 and GW151226

TL;DR

This study searched for neutrino signals coincident with gravitational wave events GW150914 and GW151226 using Super-Kamiokande, setting upper limits on neutrino fluence across a wide energy range, with no significant detections.

Contribution

First to perform a neutrino search coincident with GW150914 and GW151226, establishing fluence upper limits over a broad energy spectrum with no confirmed neutrino signals.

Findings

Four neutrino candidates for GW150914, consistent with background

No neutrino candidates for GW151226

Set upper limits on neutrino fluence depending on energy and zenith angle

Abstract

We report the results from a search in Super-Kamiokande for neutrino signals coincident with the first detected gravitational wave events, GW150914 and GW151226, using a neutrino energy range from 3.5 MeV to 100 PeV. We searched for coincident neutrino events within a time window of $\pm$500 seconds around the gravitational wave detection time. Four neutrino candidates are found for GW150914 and no candidates are found for GW151226. The remaining neutrino candidates are consistent with the expected background events. We calculated the 90\% confidence level upper limits on the combined neutrino fluence for both gravitational wave events, which depends on event energy and topologies. Considering the upward going muon data set (1.6 GeV - 100 PeV) the neutrino fluence limit for each gravitational wave event is 14 - 37 (19 - 50) cm$^{-2}$ for muon neutrinos (muon antineutrinos), depending on the zenith angle of the event. In the other data sets, the combined fluence limits for both gravitational wave events range from 2.4$\times 10^{4}$ to 7.0$\times 10^{9}$ cm$^{-2}$.