Sterile neutrinos are potential candidates for dark matter. A repeated anomaly during experiments dedicated to these neutrinos seems to clarify their existence.
« The results are very exciting. At the Los Alamos lab, an intriguing anomaly has been detected during a major experiment. It is relayed in two studies (1, 2) published on June 9, 2022, as well as on the observatory website. This anomaly could well be the sign of “sterile neutrinos”, which remain, for the moment, purely hypothetical.
Neutrinos are already, in themselves, ghostly particles. The Universe is full of them, our Sun sends us billions of them every second, but these elementary particles remain very difficult to observe. They have no mass or electric charge. They slip through the densest materials and only interact in the weak nuclear field. To hope to see traces of it, you need observatories like the Super-Kamiokande in Japan – a huge tank of water, several hundred meters underground, with walls strewn with thousands of detectors supposed to detect interactions with water.
As they move, neutrinos oscillate between three flavors (a set of physical properties): electronic, muonic, tauic. Except that, in the 1990s, experiments suggested the existence of a fourth flavor, a phase where the neutrinos would not even interact via the weak nuclear interaction.