In the meantime, in 2020 a bunch of 170 consultants referred to as the Muon g-2 Concept Initiative printed a new consensus value of the theoretical value of muon’s magnetic moment, based mostly on three years of workshops and calculations utilizing the Commonplace Mannequin. That reply bolstered the unique discrepancy reported by Brookhaven.
Reached by cellphone on Monday, Aida X. El-Khardra, a physicist on the College of Illinois and a co-chair of the Muon g-2 Concept Initiative, mentioned she didn’t know the end result that Fermilab can be saying two days later — and he or she didn’t need to, lest she be tempted to fudge in a lecture scheduled simply earlier than the official unveiling on Wednesday.
“I’ve not had the sensation of sitting on sizzling coals earlier than,” Dr. El-Khadra mentioned. “We’ve been ready for this for a very long time.”
On the day of the Fermilab announcement one other group, utilizing a distinct method referred to as a lattice calculation to compute the muon’s magnetic second, concluded that there was no discrepancy between the Brookhaven measurement and the Commonplace Mannequin.
“Sure, we declare that there is no such thing as a discrepancy between the Commonplace Mannequin and the Brookhaven end result, no new physics,” mentioned Zoltan Fodor of Pennsylvania State College, one of many authors of a report published in Nature on Wednesday.
Dr. El-Khadra, who was accustomed to that work, known as it an “superb calculation, however not conclusive.” She famous that the computations concerned have been horrendously sophisticated, having to account for all potential ways in which a muon may work together with the universe, and requiring hundreds of particular person sub-calculations and tons of of hours of supercomputer time.
These lattice calculations, she mentioned, wanted to be checked in opposition to impartial outcomes from different teams to remove the opportunity of systematic errors. For now, the Concept Initiative’s calculation stays the usual by which the measurements will probably be in contrast.