We define neutrinos as very light subatomic particles that practically do not interact with visible matter. We know of three types of neutrinos (the muon, the tau, and the electron), and the search for the fourth has been going on for decades. I’m talking about so-called sterile neutrinos. Its advantage is that it only interacts with matter by gravity. Unfortunately, the search for sterile neutrinos was unsuccessful.
Several theoretical physicists have found the sterile neutrino idea promising because it has the potential to explain many of the anomalies found in particle physics experiments as well as being related to the mysteries of dark matter. But since neutrinos are very small and weakly interact with other matter, we can only observe them indirectly, as a result of collisions with other particles.
In the 1990s and early 2000s, two neutrino experiments found more of these products than expected. However, neither could distinguish electrons from photons – and sterile neutrinos would only produce additional electrons, not photons. A new experiment called MicroBooNE at the Fermi National Accelerator Laboratory (Fermilab) in Illinois could differentiate the two, but the first three years of data revealed no additional neutrino products.
“I was expecting to see an excess of photons or electrons, and we didn’t see any, which raises more questions. We still don’t have a way to explain the previous findings, so they can point to more exotic physical processes,” said Justin Evans of the University of Manchester, a spokesman for MicroBooNE. Not yet covered.
Is the search for sterile neutrinos over?
We certainly don’t see any evidence of sterile neutrinos. As for whether it’s a dead idea, that depends on who we ask. You definitely need to be more creative to incorporate sterile neutrinos into new models of particle physics,” added Justin Evans.
