Photo: Fermi scientist Rob Roser at his Elburn home with hunting dogs Pete and Maggie. Roser and his wife Laurie spend their spare time bird hunting with the dogs. Photo by Sandy Kaczmarski
by Sandy Kaczmarski
BATAVIA—The scene: Scientists from around the world wait as the particles are readied to be shot through the Earth at unbelievably high speeds. Their path deep inside the planet is to keep cosmic rays from the universe from impacting the detector.
Destination: The old Homestake gold mine in the hills of South Dakota, where the particles will be smashed into a target a mile into the ground. The reason for this scientific exercise is to try to understand why these particles, called neutrinos, break bad.
Neutrinos don’t follow the Laws of Nature.
While this sounds like the opening of a science fiction movie, it’s all part of what’s on the horizon for Fermi National Accelerator Laboratory in Batavia. Fermilab scientist Rob Roser, of Elburn, calls it “the intensity frontier.”
“Neutrinos are particles that don’t interact at all with matter. So you can literally make them and point them in the right direction and they will just keep going,” Roser said. “Neutrinos don’t follow our expectations with the Standard Model (of particle physics).”
Roser said a good way to try to understand the universe is to acknowledge that scientists don’t understand these particles.
“So let’s build experiments to really try to understand them; why they don’t follow the Laws of Nature that we expect them to follow,” he said.
Roser, 49, has been a staff scientist at Fermi since 1997. He grew up in New England, not far from Hartford, Conn., in what used to be a farming community, but what he says now is a “yuppie” haven.
Roser has been studying collisions of protons and anti-protons with the super-conductor Tevatron. He said the latest incarnation of these experiments were running the last 10 years “pretty much 24-hours a day, 365 days a year.”
“If something occurs one in a billion times, or one in a trillion times, you need an awful lot of trillions of collisions in order to see it,” Roser explained. “So discoveries we’ve made at Fermilab or in particle physics are not ‘eureka’ moments where all of a sudden you have a single collision and you produce your new found object and then you’ve got something. It’s a statistical process.”
Tevatron was shut down on Sept. 30, 2011, and Roser explained that its demise was inevitable.
“These machines always have a finite lifetime,” he said. “You plan them for a certain amount of time, but when the new machine comes along and can do more, the plan is to turn this one off. It was the world-class machine for 20 years.”
That new machine is the Large Hadron Collider (uslhc.us/) which started operating in 2008 and is located in Geneva, Switzerland. Roser said it “actually blew up a piece of itself” shortly after it was activated and it took another year and a half to fix. But Roser said it’s a fancier version of the Tevatron, and instead of being four miles in circumference, it’s 18 miles in circumference.
Roser said about a third of Fermilab’s 300 scientists are engaged in the energy frontier and will continue their work at the LHC. Many of the remaining scientists will continue in the U.S. working on the intensity frontier or in particle astro physics, looking for dark energy and dark matter.
Roser also said there are actually five accelerators at Fermilab, all of which were needed to make the Tevatron work. The other four accelerators are still active on other experiments.
These days, that would include a quest to find and understand Higgs boson, which is described in a “Fermilab Today” article as a “key member of the particle zoo known as the Standard Model.”
“The most amazing thing is we’ve been doing this game for a long time and something as simple as mass, from a chemistry point of view, we understand,” Roser said. “But from a particle physicist’s point of view, we don’t understand it at all.”
There are six quarks in the Standard Model and each has a different mass. Roser says scientists don’t know why.
“The whole universe has a Higgs field that permeates it and how strongly each particle couples to that Higgs field is what gives it its mass,” he said. “The question is, is it right? Just because it’s a beautiful theory, doesn’t mean it’s right.”
Roser wanted to make clear that Fermilab has a very bright future ahead of itself. But he said within the next decade, the United States will have to make a decision to invest more in research and development. He points to a book called, “The Science and the Wealth of Nations,” that makes a strong case that if countries don’t invest in fundamental R&D, then the standard of living in those countries will fall.
“That’s where your real discoveries come from,” he said. “You don’t really know what they may be yet, but they will come if you do it.”
About fundamental research, he said, “all of it is important.”
Learn more about the neutrino experiment at fnal.gov/pub/science/experiments/works-in-progress/ and the CERN collider at cern.ch/.