Possible High-Energy Neutrino Emission from Dark Matter Annihilation in the Disrupting Dwarf Galaxy Bo" o tes III

We report the first search for high-energy neutrino emissions from dark matter (DM) annihilation in stellar-stream cores. Motivated by a recent gamma-ray study that proposed these cores as a new class of indirect DM targets, we analyze three stream cores in the Northern Hemisphere using the public ten-year track-like neutrino data released by IceCube. Under the χχ toν ν annihilation hypothesis, the most significant excess among the three targets is found at the position of the nearby dwarf galaxy Boötes III, the core of the Styx stream, with the DM mass of m χ 10 -- 31 TeV. The excess has a post-trial significance of 3.1σ. Considering the existing IceCube dwarf-galaxy limit for the same channel, we obtain a limit on the J-factor J ann, 10(J ann/ GeV squared,cm-5) 19.1+0.3-0.5. This limit is broadly consistent with empirical estimates of J ann for Boötes III. The results provide the first candidate target with a possible HE neutrino signal associated with DM annihilation. This neutrino excess and the general existence of DM-induced neutrino signals from other similar sources will be confirmed with the near-future large high-energy neutrino detectors, thus enabling us to probe the nature of DM particles.