Search for sterile neutrinos in MINOS and MINOS+ using a two-detector fit
Authors: Justin Evans, Rui Chen, Ashley Timmons
Journal: Physical review letters
Publication Date: 06 March, 2019
Department of: Physics and Astronomy
Neutrinos travel 500 miles to shed light on a longstanding puzzle of particle physics
A longstanding question in particle physics is whether we have discovered all types of neutrino. Three types are known; called ”active” neutrinos, since they interact with other matter, these are the electron, muon and tau neutrino. But these neutrinos have strange properties: they are much lighter than any other massive particle, and they only seem able to spin in one direction. These puzzles suggest there is more to be discovered about the neutrino. One key question is whether there are additional types of neutrino that have not yet been observed. For these to be hidden, they would have to be incapable of interacting with matter, hence they are called ”sterile” neutrinos. To search for sterile neutrinos, a process of neutrino oscillation is used: thanks to quantum mechanics, one type of neutrino is able to turn into another as it travels.
Researchers from the University of Manchester in collaboration with scientists from the USA, Brazil and Greece, used data from the MINOS+ experiment, which sent muon neutrinos 457 miles from Fermilab in Chicago to the Soudan Underground laboratory in northern Minnesota. The experiment aimed to look for evidence of any of the muon neutrinos turning into sterile neutrinos as they travel. The results provide no evidence of the neutrino transformation, and are able to set one of the most stringent limits ever made on the existence of sterile neutrinos.
The Manchester neutrino group are now leading the construction of the new DUNE experiment, which aims to measure the properties of neutrinos with even greater precision, in particular hoping to discover an asymmetry between neutrinos and antineutrinos that could help us to understand the evolution of the universe.
- Neutrino physics: new limits on the existence of sterile neutrinos