No Evidence of Mirror Neutrons Found in Swiss PSI Ultracold Neutron Experiment
The Ultracold Neutron Physics Group at the Paul Scherrer Institute (PSI) in Switzerland recently stated that its research team found no evidence of spontaneous transformation of ordinary neutrons into mirror neutrons in a high-precision experiment. The researchers said the result essentially rules out the main parameter space previously suggested for anomalous neutron-mirror neutron oscillation signals, and also weakens the possibility that mirror neutrons could be a component of dark matter. Bernhard Lauss (left) and Géza Zsigmond examined approximately 2.5 billion neutrons at the ultracold neutron source at the Paul Scherrer Institute (PSI). They essentially ruled out the hypothesis of spontaneous transformation of neutrons into mirror neutrons. (Image courtesy of Paul Scherrer Institute PSI/Ma...
2026-09-07