KATRIN experiment finds no evidence for sterile neutrinos

The KATRIN experiment has conducted the most precise direct search for sterile neutrinos, finding no evidence for their existence. This result significantly constrains theories proposing a fourth type of neutrino. The experiment measured tritium beta decay with high accuracy, looking for a specific distortion in the electron energy spectrum that would indicate a sterile neutrino. The findings exclude a large parameter space previously suggested by anomalies in other experiments. KATRIN's data collection continues through 2025, with future upgrades planned to further increase sensitivity and explore higher mass ranges for sterile neutrinos, which could potentially be dark matter.