Physicists from the nova collaboration presented the results of the search for sterile neutrino – hypothetical particles that can exist along with three known types of neutrinos, but interact only through gravity. The study did not reveal signs of the existence of sterile neutrinos, but allowed us to narrow the range of permissible parameters, imposing new restrictions on their properties.
Nova experiment, based in Fermilabe (USA), uses the flow of muon neutrinos generated in the collision of protons with carbon target. Some neutrinos are fixed with a detector in Fermilabe, others – a detector at a distance of 810 km in Minnesota. Researchers analyzed whether muon neutrinos can turn not only into electronic ones, as the standard model predicts, but also in the fourth, sterile type.
The results did not confirm the hypothesis of the existence of sterile neutrinos, and also excluded a number of parameters previously allowed by the experiments of ICECUBE, LSND and MINIBOONE. Although Nova did not investigate the same parameters as LSND and Minibooone, its conclusions contradict their hints of the existence of sterile neutrinos. The question remains open, but new data significantly narrow the space for searches.