What is a neutrino?
A neutrino is one of the family of truly fundamental particles in nature. It has no electric charge and it interacts only weakly with matter and light, so neutrinos can reach us from distances comparable with the size of the Universe. Current research focuses on two aspects, what are the masses and other properties of the neutrinos themselves and what can they tell us about energetic events in the Universe.
Neutrinos are the most abundant particles in the universe that have mass, though they are outnumbered by massless photons. Most of the Universe's neutrinos are leftovers from the Big Bang, but some are created during hydrogen fusion in stars, in supernovae, or during mergers of black holes and neutron stars. Atoms that undergo beta decay produce neutrinos and antineutrinos, as do nuclear reactors. In fact, some scientists and policy makers have proposed building sensitive neutrino detectors to monitor nuclear proliferation across the globe.
Astronomers and particle physicists have detected neutrinos from the sun, Supernova 1987A, and unidentified astrophysical sources -- violent events in the cosmos that unleash tremendous energy and produce neutrinos traveling at nearly the speed of light. University of Delaware scientists contributed to IceCube Neutrino Observatory's detection of astrophysical neutrinos, which was awarded the 2013 Breakthrough of the Year Award by PhysicsWorld magazine.
More resources on neutrinos:
- All About Neutrinos from IceCube
- Newsworks profile of UD neutrino physicist Tom Gaisser
- Yes, but what are neutrinos for? Boston Globe story
-Tom Gaisser and Sally Dodson-Robinson
