Science

Neutrinos

Our universe is permeated with neutrinos — nearly massless, neutral particles that interact so rarely with other matter that trillions of them pass through our bodies each second without leaving a trace. These tiny particles, studied in world-leading Fermilab experiments, could be key to a deeper understanding of our universe.

Neutrinos, first discovered in 1956, have some mysterious characteristics. They have puzzlingly low masses, compared to other elementary particles, and they are able to oscillate, or change from one type of neutrino to another.

The Standard Model, the best description of the fundamental particles and forces that make up our universe, predicted the existence of neutrinos. But it also predicted that the lightweight particles would have no mass at all. It could be that neutrinos are the only fundamental particles that gain their mass from a source other than the just-discovered Higgs field.

Neutrinos could have other strange properties as well. They could turn out to be identical to antineutrinos, their antimatter counterparts. They could be related to massive particles that theorists think might have greatly influenced the formation of our universe.

Studying neutrinos could tell us about other areas of physics as well. They could give us insight into why particles seem naturally to be organized into three generations. They could help reveal undiscovered principles of nature.

Scientists at Fermilab have been involved in neutrino research since the 1970s. In 1999, the laboratory broke ground on its first long-baseline neutrino experiment, MINOS, which studies the oscillation of muon neutrinos to tau neutrinos. The DONUT experiment at Fermilab made the first ever direct observation of a tau neutrino in 2000.

Scientists have proposed a number of other experiments and facilities to learn more about the properties and behaviors of neutrinos. One of these proposed experiments is Fermilab's flagship, the Deep Underground Neutrino Experiment, to be conducted at the international Long-Baseline Neutrino Facility in South Dakota.

Learn more about Fermilab experiments below and visit the Fermilab Neutrino Division website.

DUNE

The Deep Underground Neutrino Experiment, DUNE, is a proposed international neutrino experiment that would be the largest of its kind. DUNE aims to make definitive determinations of neutrino properties, the dynamics of the supernovae that produced the heavy elements necessary for life and the possibility of proton decay. DUNE research will be conducted with the international Long-Baseline Neutrino Facility, LBNF, at Fermilab and the Sanford Underground Research Facility in South Dakota.

Short-Baseline Neutrino Program

The Short-Baseline Neutrino Program at Fermilab will look for a fourth neutrino, one that may not follow the rules of neutrino oscillations and interactions shown by the other known three. When construction is complete, a chain of three particle detectors — ICARUS, MicroBooNE and SBND — will probe a beam of neutrinos created by Fermilab's particle accelerators. MicroBooNE, the middle detector, is currently operational. It is a multiton liquid-argon detector and uses the same technology that will be used for DUNE. ICARUS, the most distant of the three, is currently undergoing refurbishment at the CERN research center in Switzerland. SBND, which will sit closest to the source of the neutrino beam, will be a 260-ton liquid-argon detector. Together these three detectors will be powerful tools to investigate in great detail the evolution of neutrino oscillations over short time and distance.

NOvA

Fermilab's current flagship neutrino experiment, NOvA sends a beam of neutrinos to a 14,000-ton particle detector a record-breaking 500 miles away in Minnesota. NOvA aims to study the oscillation of muon neutrinos to electron neutrinos, to determine the ordering of neutrino masses and to discover whether neutrinos and antineutrinos oscillate at different rates.

MINOS

MINOS is a neutrino oscillation experiment with a far detector located in a former mine in Minnesota. It aims to observe neutrino oscillations by measuring the disappearance of muon neutrinos and the appearance of electron neutrinos.

MINERvA

MINERvA is a neutrino-scattering experiment that uses a variety of target materials to search for low-energy neutrino interactions. It is designed to study neutrino-nucleus interactions with unprecedented detail.