Speaker
Description
Recently there have been stronger and stonger disagreements between direct measurements of the anomalous magnetic moment of the muon and the standard-model prediction. Such a large discrepancy should signal the discovery of interactions or particles not present in the standard model. However, two independent determinations of the most uncertain contribution to the standard-model prediction display significantly less tension with the measurement. Here we present a new first-principle calculation of this contribution. We reduce uncertainties compared to our earlier (2020) BMW computation by 40%. To reach this unprecedented level of precision we improve on many aspects of the calculation. Namely, we perform large-scale lattice QCD simulations on finer lattices than in 2020, allowing for an even more accurate continuum extrapolation. We also include a small, long-distance contribution obtained using input from experiments in a low-energy regime where they all agree. Combined with the extensive calculations of other standard model contributions, our result leads to a prediction that differs from the direct measurement by only 0.9 standard deviations. This provides a remarkable validation of the standard model to 0.37ppm.
Details
Zoltan Fodor, Prof., Penn State/Wuppertal/Juelich, USA/DE, http://particle.uni-wuppertal.de/fodor/
| Internet talk | No |
|---|---|
| Is this an abstract from experimental collaboration? | No |
| Name of experiment and experimental site | N/A |
| Is the speaker for that presentation defined? | Yes |