Search for neutrino doublets and triplets using 11.4 years of IceCube data

TL;DR

This study searches for clusters of high-energy astrophysical neutrinos in 11.4 years of IceCube data, using a new method optimized for transient emissions on a monthly timescale, but finds results consistent with background noise.

Contribution

Introduces a novel search method optimized for detecting transient neutrino emissions on a monthly timescale in IceCube data, enhancing sensitivity to such events.

Findings

Number of neutrino multiplets consistent with background expectations

Set limits on transient neutrino source fluxes

Demonstrated the effectiveness of the new search method

Abstract

We report a search for high-energy astrophysical neutrino multiplets, detections of multiple neutrino clusters in the same direction within 30 days, based on an analysis of 11.4 years of IceCube data. A new search method optimized for transient neutrino emission with a monthly time scale is employed, providing a higher sensitivity to neutrino fluxes. This result is sensitive to neutrino transient emission, reaching per-flavor flux of approximately $10^{-10}\ {\rm erg}\ {\rm cm}^{-2}\ {\rm sec}^{-1}$ from the Northern sky in the energy range $E\gtrsim 50$~TeV. The number of doublets and triplets identified in this search is compatible with the atmospheric background hypothesis, which leads us to set limits on the nature of neutrino transient sources with emission timescales of one month.