The Northern Illinois University (NIU) Board of Trustees unanimously voted Dec. 7 to extend the…
DeKalb, Ill. – NIU can take more than a little pride in its contributions to the latest landmark finding at the U.S. Department of Energy’s Fermi National Accelerator Laboratory in nearby Batavia.
Over the years, nearly 50 NIU faculty and student researchers contributed to Fermilab’s “Muon g-2 experiment.” It uses powerful accelerators to explore the properties and interactions of muons—tiny subatomic particles that are abundant in nature but exist for only 2.2 millionths of a second. The first results from the Muon g-2 experiment made headlines early this month in news outlets worldwide, from the New York Times to the BBC.
So what’s all the fuss about?
For the past five decades, the Standard Model of particle physics, the top scientific theory explaining the nature of matter, has been amazingly accurate in predicting the behavior of the subatomic building blocks of our universe. But Fermilab’s long-awaited first results from its “Muon g-2 experiment” show muons behave in a way that is not predicted by the theory.
The strong evidence that muons deviate from the Standard Model hints at exciting new physics. Many scientists suspect muons must be interacting with an undiscovered particle or hidden force of nature.
“The Standard Model does an incredible job of predicting the forces and interactions of nature, and it explains everything from how our universe formed to nuclear fusion at the sun’s core,” NIU physicist Michael Eads says. “However, the g-2 results provide the best evidence to date that there is something else going on that is unexplained by the Standard Model. The results tell us there are likely additional unknown particles or forces or both at play.”
The Muon g-2 experiment, located on the Fermilab Muon Campus, involves an international collaboration among Fermilab, Brookhaven National Laboratory in New York, and dozens of labs and universities in seven countries.
Most of NIU’s involvement was in preparation for the experiment, with the university’s contingent led by Eads, Physics Professor Michael Syphers and Mechanical Engineering Professor Nicholas Pohlman. Over the past nine years, 44 NIU students also have contributed to the experiment, as well as now retired Physics Professors David Hedin and Michael Fortner.
Syphers, who has a joint appointment between NIU and Fermilab, was part of a small group of original proponents who advocated more than a decade ago to bring the Muon g-2 experiment to Fermilab, which is about a 40-minute drive east from NIU. They foresaw that the scheduled 2011 shutdown of the main Fermilab accelerator, the Tevatron, created an opportunity to reconfigure the laboratory complex to perform lower-energy but higher-intensity particle beam experiments like g-2.
The predecessor experiment of g-2 at DOE’s Brookhaven National Laboratory had concluded in 2001 and offered hints that the muon’s behavior disagreed with the Standard Model. In the summer of 2013, that experiment’s massive 700-ton electromagnet was transported over land and sea from Brookhaven to Fermilab. In the ensuing years, the experiment has been retooled, upgraded and rebooted.
Syphers helped develop the muon beam delivery process from the Fermilab accelerator system and more recently was involved in error analysis. Two of his graduate students and one post-doc have worked on the experiment as well.
“Beam physicists and students at NIU have been involved with the experiment for several years and made valuable contributions to the production, confirmations and understanding of the muon particle beam produced for this experiment,” Syphers says. “We have also contributed to computational studies and measurements that have fed directly into the initial results revealed in this recent announcement.
“Many NIU physics students, even those not involved directly with this experiment, have had access to Fermilab and have participated in discussions and talks regarding this experiment,” he adds. “They have benefitted from direct contact with g-2 scientists and engineers and their experiences and expertise.”
Professors Eads and Pohlman contributed to the design, construction and quality control of the tracker system, which detects particles known as positrons that result from the decay of muons. They also worked with their students on the design, installation and calibration of the experiment’s “slow controls” system, which measures and records various parameters in the experimental hall, such as temperatures, humidity, air pressure, voltages and currents.
Eads notes that five of his past graduate students focused their master’s theses on the g-2 experiment. Additionally, he arranged for five undergraduates, one high school teacher and two high school students to collaborate on the project.
Meanwhile, Pohlman led extraordinary involvement from NIU engineering. Three graduate students and 28 undergrads, many of them working in Senior Design teams, contributed to development of the tracker system.
“Seeing the tracker system, from starting concept through fabrication and operations, was a great opportunity for students to get a feel for how complex challenges can be solved while working in large collaborations,” Pohlman says.
“Physicists do a great job of drawing up conceptual ideas, and engineers turn those sketches into real-world devices,” he adds. “For our students, this has been a great real-world experience.”
Syphers also felt the collaborative nature of the experiment was amazing.
“We all knew it was important and what was possibly at stake, so everyone has been very professional and serious about the work,” he says. “But at the same time, it has just been a great group of humans to be around all this time. My hope is that future NIU students will somehow be able to get a taste of the excitement of doing science and learning about their universe first-hand through efforts like this one.”
NIU is also involved in the Mu2e experiment on Fermilab’s Muon campus. That experiment searches for rare decays of the muon – another hint for new physics. More exciting results are expected from both g-2 and Mu2e in the future.
Media Contact: Tom Parisi
Northern Illinois University is a student-centered, nationally recognized public research university, with expertise that benefits its region and spans the globe in a wide variety of fields, including the sciences, humanities, arts, business, engineering, education, health and law. Through its main campus in DeKalb, Illinois, and education centers for students and working professionals in Chicago, Hoffman Estates, Naperville, Oregon and Rockford, NIU offers more than 100 areas of study while serving a diverse and international student body.