It took two years for researchers using the vast IceCube Neutrino Observatory to uncover a population of the chargeless, featherweight particles that originated beyond the solar system. They would need a decade more, it turns out, to confirm that those energetic particles come in all three neutrino flavors. To pair with its previous measurements of cosmic muon and electron neutrinos, the IceCube collaboration now reports identifying seven candidate tau neutrinos, the most elusive variety of neutrino because its partner lepton decays so rapidly.
The candidates were plucked from nearly 10 years of data acquired from the IceCube detector, whose more than 5000 light sensors are attached to cables that are frozen within an Antarctic ice sheet. Whether produced in a laboratory or in a galaxy billions of light-years away, neutrinos are constantly oscillating between flavors until they interact with other matter. When such an interaction occurs, including in the dark...
