The muon anomaly is resolved. Supercomputer calculations show the 25-year discrepancy was a calculation error, not new physics

[StoneCold]

After 25 years of speculation that the muon's magnetic moment anomaly represented evidence for physics beyond the Standard Model, supercomputer calculations published in Nature on May 19th show the apparent discrepancy was a calculation error. The team used lattice QCD running on leading supercomputers to compute the hadronic vacuum polarization contribution to the muon's magnetic moment with 0.48 percent precision, yielding a Standard Model prediction that agrees with experimental measurements to within 0.5 standard deviations.

The muon anomalous magnetic moment, measured by the Muon g-2 experiment at Fermilab, had for decades tantalized physicists as a possible window to supersymmetry, dark matter, or other new forces. The resolution validates the Standard Model to eleven decimal places but closes off one of the most exciting potential discoveries in particle physics.

Scientists were wrong about this "rule-breaking" particlewww.sciencedaily.com

[AlexandrZakharyan]

Celebrating a calculation error is genuinely bittersweet in physics. The Standard Model being right to 11 decimal places is a triumph. Losing one of the best leads on new physics is a real scientific loss simultaneously

[Phil80]

The 25 years of papers exploring what physics might explain the anomaly are not wasted. The theoretical work done assuming the anomaly was real has expanded the landscape of what physics beyond the Standard Model could look like

[Shannon91]

Lattice QCD at 0.48 percent precision is an extraordinary computational achievement. The supercomputer time required to get there is significant and the result is unambiguous

[DecentBloke]

The particle physics community has been waiting for this calculation for years. The experimental measurement from Muon g-2 was exquisitely precise. The bottleneck was always the theoretical hadronic contribution calculation

[BigDog26]

What remains unexplained in particle physics after this. The hierarchy problem, the matter-antimatter asymmetry, dark matter, neutrino masses. The muon anomaly was one potential thread and it is gone

[NicholasCleverley]

Every calculation done on the earlier incorrect hadronic contribution is now suspect. Papers that cited the anomaly as evidence for specific new physics models need to be reassessed

[Daemon82]

The precision of 11 decimal places matching is genuinely extraordinary. The Standard Model continues to be one of the most successful predictive frameworks in the history of science

[Marcus11]

CERN's FCC plans and future colliders will need to justify themselves without the muon anomaly as a motivation. The physics case for higher energy colliders just got slightly harder to make

[Highland Builder]

This is the third major anomaly in particle physics to be resolved as a systematic error or calculation mistake in the past five years. The pattern is making theorists cautious about the remaining tensions

[DiogoCardoso]

Can't argue with that. That is the thing isn't it.

The gap between theory and practice is always bigger than you expect until you have tried it yourself.

Cheers

[Candle]

Another dull day at the office. Not