The biggest particle physics project in North America is getting its groundbreaking, and CU Boulder is involved.
Our understanding of the universe may soon be changing thanks to the efforts of a thousand scientists from around the world, including two from the University of Colorado Boulder.
Alysia Marino, an associate professor, and Eric Zimmerman, a professor in the Physics Department at CU Boulder, are both working on the construction of the Long-Baseline Neutrino Facility (LBNF), which will eventually house the Deep Underground Neutrino Experiment (DUNE).
This project will be the largest particle physics experiment ever undertaken in North America, and is supported by both the Fermi National Accelerator Laboratory (Fermilab) and CERN, a massive particle-physics laboratory in Switzerland.
LBNF, which is celebrating its groundbreaking Friday, will eventually shoot a beam of neutrinos through the Earth's crust from Illinois to South Dakota, all to better understand how and why the universe formed. The project, which has been in the works for close to a decade, will take roughly another decade to build before the first beam is finally shot.
"It's a long process, but this is certainly the first step. It's exciting to see it become closer to reality," said Marino.
Neutrinos, the central part of this whole experiment, are the most abundant matter particle (or, the most abundant "thing") in the universe and a central building block in its formation. They are everywhere at all times, and yet they have almost no mass and no electrical charge, so they do not bind to anything. They simply exist, born from the sun or some distant star, as they move through the planet.
Yet, despite this knowledge, their role in the universe is still mysterious to the scientists who study them.
DUNE, and the corresponding LBNF, seek to change this and, thus, alter our understanding of how the universe came to exist in its current form of matter instead of antimatter.
"One of the biggest open questions in physics right now is how the universe began to be dominated by matter instead of antimatter, because any reaction that we’ve made in the lab… if you produce a particle of matter, you produce a precisely equal amount of antimatter. So, if that’s how the early universe evolved, then all of the matter and antimatter would have annihilated each other out and there’d be nothing left except energy. Obviously, that didn’t happen," Zimmerman said.
"There's got to be something else. We know there’s got to be something else, and neutrinos are a major candidate for that."
DUNE will measure neutrinos by firing a proton beam from Fermilab, a Department of Energy laboratory near Chicago, to the Sanford Underground Research Facility in Lead, S.D. The proton beam, which is similar to a cosmic ray from the sun, will hit a controlled carbon nucleus (which, in this case, will probably be a wall of graphite) and eventually decay down to muons (a particle that produces the bulk of the cosmic radiation we receive on Earth) and neutrinos.
To measure this phenomenon, a "near" detector will be constructed right outside of Fermilab and the beam, and then again in South Dakota (which would be the largest in the world, located almost a mile underground in an abandoned gold mine) to see how much the neutrinos decay and transform along the 4-millisecond trip.
By examining these tiny parts of the universe, the scientists are hoping to shed light on three things: the origin of matter (versus antimatter), the unification of forces (which will be examined through proton decay, along with the neutrinos) and the formation of black holes (as DUNE can potentially detect supernova explosions).
"DUNE will be able to make these measurements way, way better than anything that exists now," remarked Zimmerman.
This experiment builds upon existing neutrino research, including one piece that was awarded the 2015 Nobel Prize in Physics for discovering that neutrinos can change from one kind to another.
"It's important that we're involved, and we're going to get, hopefully, a lot more generations of students involved in this as well," said Marino.
While the groundbreaking is scheduled for Friday, the project faces many barriers—including funding.
"The biggest threat to DUNE right now is the uncertainty about the federal budget," said Zimmerman. While LBNF is an international collaboration, most support for the project comes from Fermilab and the Department of Energy, and in the President's Budget Request, research across all of the department would be cut by 18 percent from its current levels.
If that were to come to pass, the lack of funds would cripple construction, having a "very severe impact on the research."
For more information on the DUNE project, including additional information and materials, see the project's website. For information on CU's involvement, contact Alysia Marino (firstname.lastname@example.org) or Eric Zimmerman (email@example.com).