Neutrinos
The lab’s suite of experiments to study the subtle, elusive particle called the neutrino will aid humanity’s understanding of the origin of matter, the unification of forces and the Big Bang. Before being detected, neutrinos from Fermilab experiments travel over short distances — several hundred meters — and over long distances — several hundred miles.
Fermilab is hosting what will be the largest experiment of its kind when complete: DUNE at LBNF. At Fermilab’s flagship experiment DUNE, the Deep Underground Neutrino Experiment, the lab will send neutrinos 800 miles through Earth’s mantle to a former gold mine in Lead, South Dakota. Scientists will use giant detectors to study the neutrinos’ travel patterns over that distance, recording neutrino interactions at either end of the journey. Scientists will search for new subatomic phenomena and potentially transform our understanding of neutrinos and their role in the universe. The Long-Baseline Neutrino Facility will provide the neutrino beamline and the infrastructure that will support the DUNE detectors.
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. While small and antisocial, neutrinos are the most abundant particle with mass in the universe — so the sheer number of them could have a powerful collective effect. Their odd properties could be a clue to a deeper understanding of the most fundamental physics in the universe, which is why Fermilab has put together a suite of world-leading experiments.
Neutrinos, first discovered in 1956, come in three flavors (or types) and have some mysterious characteristics. They have puzzlingly low masses when 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 that neutrinos would have no mass. However, we know from oscillation experiments that neutrinos do have tiny masses. It could be that neutrinos are the only fundamental particles that gain their mass from a source other than the Standard Model 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. 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 studied the oscillation of muon neutrinos to tau neutrinos into other flavors. The DONUT experiment at Fermilab made the first ever direct observation of a tau neutrino in 2000.
Learn more about Fermilab experiments below and visit the Fermilab Neutrino Division website. And for a thorough primer on neutrino physics, visit All Things Neutrino. All Things Neutrino is a comprehensive site that covers the history, science and intrigue behind these subtle particles.