A search for correlated low-energy electron antineutrinos in KamLAND with gamma-ray bursts

TL;DR

This study searches for low-energy electron antineutrinos coinciding with gamma-ray bursts using KamLAND, setting new upper limits on neutrino fluence and constraining source properties based on non-detection.

Contribution

It provides the most stringent upper limits on electron antineutrino fluence from gamma-ray bursts and constrains their neutrino luminosity and temperature.

Findings

No significant neutrino excess detected

Set the world's most stringent 90% CL upper limit on fluence

Constrained neutrino luminosity and temperature of GRB sources

Abstract

We present the results of a time-coincident event search for low-energy electron antineutrinos in the KamLAND detector with gamma-ray bursts from the Gamma-ray Coordinates Network and Fermi Gamma-ray Burst Monitor. Using a variable coincidence time window of $\pm$500s plus the duration of each gamma-ray burst, no statistically significant excess above background is observed. We place the world's most stringent 90% confidence level upper limit on the electron antineutrino fluence below 17.5 MeV. Assuming a Fermi-Dirac neutrino energy spectrum from the gamma-ray burst source, we use the available redshift data to constrain the electron antineutrino luminosity and effective temperature.