Petrov: 'New particles, new physics might be just beyond our research'

Wayne State University Physicist Alexey Petrov recently discussed a potential new breakthrough in physics research with international media.

A potential chink in physicists' understanding of fundamental particles and forces now looks more real. New measurements confirm a fleeting subatomic particle called the muon may be ever so slightly more magnetic than theory predicts, a team of more than 200 physicists reported this week. That small anomaly-just 2.5 parts in 1 billion-is a welcome threat to particle physicists' prevailing theory, the standard model, which has long explained pretty much everything they've seen at atom smashers and left them pining for something new to puzzle over.

We're thrilled to announce that the first results from Fermilab's Muon g-2 experiment strengthen evidence of new physics! #gminus2https://t.co/tUx4ojzIps pic.twitter.com/t1ufui2Mwu

- Fermilab (@Fermilab) April 7, 2021

"Since the 1970s we've been looking for a crack in the standard model," Petrov told Science Magazine. "This may be it." The immediate responses to the new result will likely be twofold, Petrov says. First, with the experimental value confirmed, physicists will likely question the theoretical estimate anew.

Starting in 2017, more than 130 theorists met in a series of workshops to hammer out a consensus value for the standard model prediction, which they published in November 2020. But Petrov says the calculation is a complicated "hodgepodge" that employs a variety of methods-including extrapolating from collider results-to account for different types of standard model particles flitting in and out of the vacuum.

Theorists will now redouble their efforts to validate the consensus value and to develop computational methods that would enable them to calculate it from first principles, Petrov says. And, of course, others will begin to concoct new theories that would go beyond the standard model and explain the muon's extra magnetism. "This is going to be a field day for theorists," Petrov predicts.

Interviews with Petrov ran in the following publications:

Science Magazine: "Particle mystery deepens, as physicists confirm that the muon is more magnetic than predicted"

Associated Press: "'Tantalizing' results of 2 experiments defy physics rulebook"

Smithsonian Magazine: "New Measurements of Muons Might Rewrite Particle Physics"