Swiss PSI Ultracold Neutron Experiment Finds No Signs of "Mirror World" Oscillation
The Paul Scherrer Institute (PSI) in Switzerland announced on July 28 that its researchers detected approximately 25 billion neutrons in an ultracold neutron experiment and found no signs of neutrons spontaneously transforming into mirror neutrons. The results constrain, with high certainty, the theoretical possibility of neutrons disappearing into the so-called mirror world. The mirror world hypothesis posits that every elementary particle in the real world may have a corresponding mirror particle, such as mirror electrons, mirror protons, and mirror neutrons. Such particles interact extremely weakly with ordinary matter, potentially connecting primarily through gravity or rare oscillations of neutral particles, and have therefore also been considered as dark matter candidates...
2026-08-03
