They’re ghostly particles created in the fusion reactions in the sun’s core and elsewhere in the cosmos, and they bombard Earth constantly, trillions of them every second, harmlessly passing through our bodies and everything around us.
Now some scientists think neutrinos could help solve an elementary problem of quantum physics: Why, when the universe was created, did matter win out over antimatter, when in theory they should have canceled each other out and left the universe empty?
About 150 physicists from around the world gathered last month at the University of Texas at Arlington to discuss plans for an estimated $1 billion project to investigate neutrinos. The Deep Underground Neutrino Experiment, or DUNE, would be the first major high-energy physics experiment on U.S. soil since the superconducting super collider project near Waxahachie was canceled in 1993.
Although neutrinos are all around us, they interact so rarely with other matter that they are very difficult to observe, and consequently, they are completely harmless.
DUNE holds such promise for groundbreaking discovery that scientists from CERN, the European Agency for Nuclear Research, are participating — the first time they’ve been part of a project outside Europe, said Christopher Mossey, project director for the Long Baseline Neutrino Facility at Fermi National Accelerator Laboratory in Batavia, Ill. Organizers hope to attract the interest of as many research institutions and governments as possible to ensure long-term funding. About 800 scientists from 150 institutions in 27 countries are already part of the effort.
“DUNE is the next big thing in particle physics,” said UT Arlington physics professor Jaehoon Yu, who hosted the January gathering. DUNE co-leaders Mark Thomson of Cambridge University and Andre Robbia of ETH Zurich in Switzerland were among those who attended.
Project organizers hope that DUNE can go online in about 10 years. Plans call for a beam of neutrinos to be sent from Fermi National Accelerator Laboratory, outside Chicago, 20 miles below the earth’s surface to the Sanford Underground Research Facility in Lead, S.D., 800 miles away. There images of the particle interactions will be captured in three dimensions by a detector in four massive liquid argon time-projection chambers. (Time-projection chambers, UTA pointed out, were developed in 1974 by David Nygren, a UTA Presidential Distinguished Professor of Physics, and have been used worldwide since then.)
But unlike the Large Hadron Collider at CERN where experimentalists discovered the elusive Higgs boson in 2012, no tunnel is needed for neutrino beams because they pass through other matter, rarely interacting with it. An Energy Department environmental study concluded that building and operating DUNE would not have a significant impact on the environment.
Neutrinos are among the most abundant particles in the universe, a billion times more abundant than the particles that make up stars, planets and people.
Besides studying the properties of neutrinos — which come in three types, or “flavors,” that can change as neutrinos pass through space — the experiment will tell scientists more about supernovas, perhaps letting them witness the creation of a black hole, and watch for evidence of proton decay. Scientists hope that by observing and comparing the oscillations of neutrinos and antineutrinos, they will discover the answer to the matter-antimatter imbalance — and the answer to how the universe came to exist.
Within DUNE, Yu leads a working group that will search for dark matter, while UTA associate physics professor Amir Farbin has a leading role in designing the computing systems. Both are members of UTA’s high-energy physics group within the College of Science.
minus 303 degrees F Temperature of liquid argon in the DUNE far detector in South Dakota
UTA physicists also played major roles in the ATLAS experiment at the Large Hadron Collider at CERN, which helped confirm the existence of the Higgs boson.
“Yet again, UTA is taking on a high-profile role that strengthens our reputation as a leading research institution, providing opportunities for our faculty and students to work with international experts at the highest level,” Duane Dimos, UTA vice president for research, said in a statement.
A closer look
What is a neutrino?
Neutrinos are harmless particles that are among the most abundant — yet least understood — in the universe; they are a billion times more abundant than the particles that make up stars, planets and people. They have no electric charge and mostly pass right through the atoms that make up ordinary matter, very rarely interacting with it. This makes them very challenging to observe.
Why is DUNE scientifically important?
Neutrinos, created in vast numbers just after the Big Bang, are crucial to understanding the origins of the universe, as well as energy and matter. DUNE may find, for example, that neutrinos are the key to solving the mystery of how the universe came to consist of matter rather than antimatter. In addition to studying neutrinos from the beamline at Fermilab, the DUNE detector is being designed to catch neutrinos emerging from supernovas, letting scientists look inside a star as it dies and collapses into a black hole. Scientists also will use the detector to look for rare subatomic interactions predicted by theories inspired by Einstein’s search for a Grand Unified Theory.
Will the neutrino beam be safe?
Yes. Unlike a focused beam of light that can heat and potentially burn objects, neutrinos neither create heat nor change the properties of the material they travel through. Unlike a laser beam, the neutrino beam will spread as it travels. By the time the neutrinos reach South Dakota, the neutrinos will be dispersed into a cone about 50 miles wide.
How do you make neutrinos?
Scientists will use one of Fermilab’s existing particle accelerators, the Main Injector, which has made neutrinos for other experiments since 2004. It accelerates protons, and smashes them into a piece of graphite or similar material where they collide with atoms, producing secondary particles. The particles that emerge from these collisions generate neutrinos.