http://www.sciencemag.org/news/2021/04/fresh-calculation-obscure-particles-magnetism-could-dim-hopes-new-physics

The peripatetic Muon g-2 experiment took data at Brookhaven National Laboratory in New York from 1997 to 2001 and has been taking data at Fermi National Accelerator Laboratory in Illinois since 2018.

Talk about raining on your colleagues’ parade. On 7 April, a collaboration of more than 200 experimenters announced to great fanfare that a particle called the muon is slightly more magnetic than predicted by physicists’ standard model, a discrepancy that could signal new particles waiting to be discovered. But on the same day, 14 theorists published a paper that suggests the consensus theoretical prediction is wrong. Their value sits closer to the experimental result and makes the tantalizing discrepancy nearly vanish.