In the meantime, in 2020 a gaggle of 170 consultants often called the Muon g-2 Concept Initiative printed a brand new consensus worth of the theoretical worth of muon’s magnetic second, based mostly on three years of workshops and calculations utilizing the Customary Mannequin. That reply bolstered the unique discrepancy reported by Brookhaven.
Reached by telephone on Monday, Aida X. El-Khardra, a physicist on the College of Illinois and a co-chair of the Muon g-2 Concept Initiative, stated she didn’t know the end result that Fermilab could be saying two days later — and he or she didn’t wish 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 scorching coals earlier than,” Dr. El-Khadra stated. “We’ve been ready for this for a very long time.”
On the day of the Fermilab announcement one other group, utilizing a distinct approach often called a lattice calculation to compute the muon’s magnetic second, concluded that there was no discrepancy between the Brookhaven measurement and the Customary Mannequin.
“Sure, we declare that there isn’t any discrepancy between the Customary Mannequin and the Brookhaven end result, no new physics,” stated Zoltan Fodor of Pennsylvania State College, one of many authors of a report printed in Nature on Wednesday.
Dr. El-Khadra, who was aware of that work, referred to as it an “wonderful calculation, however not conclusive.” She famous that the computations concerned had been horrendously difficult, having to account for all doable ways in which a muon may work together with the universe, and requiring hundreds of particular person sub-calculations and a whole bunch of hours of supercomputer time.
These lattice calculations, she stated, wanted to be checked towards unbiased outcomes from different teams to eradicate the potential for systematic errors. For now, the Concept Initiative’s calculation stays the usual by which the measurements will likely be in contrast.