JMU physicist, students team up with UVA for role in second groundbreaking discovery

A James Madison University physicist and a group of students were contributors to experiments related to the announcement of a second groundbreaking particle physics discovery at the Fermi National Accelerator Laboratory.

James Madison University physicist Kevin Giovanetti teamed up with the University of Virginia to design, prototype and build a power management system that was used as part of the experiment’s detector system.

Fermilab, the premiere particle physics and accelerator laboratory in the U.S., announced in April 2021 that the Muon g-2 experiment revealed that fundamental particles called muons behave in a way that is not predicted by scientists’ best theory, the Standard Model of particle physics.

One potential explanation for the unexpected behavior would be the existence of undiscovered particles or forces.

Fermilab announced that the latest experimental result is twice as precise as the first result.

“We’re really probing new territory. We’re determining the muon magnetic moment at a better precision than it has ever been seen before,” said Brendan Casey, a senior scientist at Fermilab who has worked on the Muon g-2 experiment since 2008. 

The Fermilab experiments confirm findings from an identical study done in the 1990s at Brookhaven National Laboratory in New York, but with greater precision.

“Our first measurement was a confirmation of the BNL experiment,” Giovanetti said.  “This was important because the BNL experiment might have been wrong, and people wondered if we would move the experimental closer to the singular theoretical value. Since our first result verified the previous experiment, the discrepancy was the key point.”

Twenty-four detector packages were deployed to detect the muons as they decayed.

“I usually describe these types of experiments as a search for a ‘Holy Grail,’ evidence that there is something new that requires rethinking and innovation,” Giovanetti said. “Clear evidence that there is a discrepancy between theory and experiment is a highly regarded result.”

Giovanetti said working on projects at national laboratories benefits his students.

“The role of integrative classroom teaching and student research has always been a hallmark of the physics department’s educational efforts and for me this has been a long-standing effort,” he said. “My status as a researcher over many years has clearly influenced my teaching and remains a critical ingredient.”