U.S. Department of Energy

Pacific Northwest National Laboratory


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Neutrino mass

Recent discoveries show that neutrinos have mass and they change between types as they travel. Physicists now know that neutrinos exist in three types and they oscillate, i.e., they change type as they move in space and time.


Mysterious and elusive particles called neutrinos morph from one type into another and back again. These “oscillations” imply that neutrinos have nonzero mass, but are also anomalously light, relative to other particles. Neutrinos may help scientists discover why the cosmos exists as we know it. There are three known neutrino types: electron neutrinos, muon neutrinos and tau neutrinos.


Neutrons have no net charge, thus are much difficult to identify and study. Due to its lack of charge, the neutron wasn’t added to the atlas of subatomic particles until 1932. The neutron’s name originates from the Latin root for “neutral.” But, we know the quarks inside are charged, so nuclear scientists use high-energy electrons to understand the neutron’s interior and answer the question ‘how does that net neutrality come about?’

New physics beyond the Standard Model

Probing more deeply for deviations from the Standard Model predictions, thus providing some other evidence for physics Beyond the Standard Model.

Non-accelerator-based experiments

The use of naturally occurring particles and phenomena to explore particle and astroparticle physics. Cosmic rays in the earth’s atmosphere and neutrinos from the sun, galactic supernovae, and terrestrial nuclear reactors serve as some of the non-accelerator-based particle sources used in this area of research.

Nuclear physics

A journey of discovery into the nucleus of the atom, which is at the heart of our ability to understand the universe. It provides answers and expands our knowledge of both the infinitely small and the extremely large.