The Ghost Particles Passing Through You Every Second

Details

Neutrinos are tiny particles with no electric charge and an extremely small mass. They are produced by the Sun, nuclear reactions, radioactive decay, particle accelerators, and other cosmic events. Enormous numbers pass through Earth and through our bodies every second, yet neutrinos interact so weakly with ordinary matter that we normally cannot feel or notice them. That unusual behavior is why they are often nicknamed ghost particles. Scientists have detected neutrinos by building very large, sensitive instruments designed to catch the rare occasions when one does interact with matter. Neutrinos also come in three known types, called electron, muon, and tau neutrinos, and they can change from one type into another as they travel, a phenomenon known as neutrino oscillation. Experiments such as the Deep Underground Neutrino Experiment are being developed to study these particles in much greater detail. DUNE will send a powerful neutrino beam through the Earth from Fermilab in Illinois to a large detector in South Dakota. Its detectors use extremely cold liquid argon so that rare neutrino interactions can produce detectable particles, electrons, and flashes of light. Better detectors could help scientists investigate questions about neutrino properties, the history of the universe, and why matter exists in much greater abundance than antimatter. The challenge is simple to describe but difficult to solve: neutrinos are everywhere, but they are remarkably difficult to catch.