Ghost hunters come up empty: Neutrino experiment finds no sign of elusive ‘sterile’ particle

The KATRIN experiment in Germany conducted the most precise search yet for a hypothetical fourth type of neutrino called a "sterile" neutrino by analyzing 36 million electrons from tritium decay over 259 days. Despite achieving sub-percent measurement accuracy, researchers found no evidence of this elusive particle, contradicting earlier experimental hints and ruling out the possibility that light sterile neutrinos significantly mix with known neutrino types.