Physicists working with a Fermilab neutrino experiment may have found a new elementary particle whose behavior breaks the known laws of physics. If correct, their results poke holes in the accepted Standard Model of particles and forces, and raise some interesting questions for the Large Hadron Collider and Tevatron experiments. The new particle could even explain the existence of dark matter.
This bad boy to the left uses 170,000 ampere current to create a magnetic field capable of directing neutrinos to a detector. When I was in high school and college, I worked at Fermilab in the electrical shop, and remember when the first neutrino detector, the Muon Lab, was built. It is interesting to see today that Fermilab still maintains some relevance.
Neutrinos have been mystifying physicists since they were first theorized decades ago. They are one of the building blocks of matter, and to the best of our knowledge, they come in three varieties, called flavors: electron neutrinos, muon neutrinos and tau neutrinos. Oscillation is what happens when neutrinos turn from one flavor to another; an electron neutrino might turn into a muon neutrino, and then turn back again. How often they do this tells physicists about the infinitesimally small differences in their masses. Neutrino mass is important because it may lead us to physics beyond the Standard Model. And that is exactly what seems to have happened.
Examining three years’ worth of MiniBooNE data, researchers detected more oscillations than would be possible if there were only three flavors. The simplest explanation is that there’s another flavor, and that it is “sterile,” meaning it does not interact with the weak nuclear force; it only interacts via gravity, which makes it really hard to detect. Incidentally, the same holds for dark matter. Sterile neutrinos could therefore help explain dark matter, which makes up most of the universe.
Ken, I'll send Stan over as he will be very interested in this post.
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