NishMath - #particles

Fermilab has announced the final results from its Muon g-2 experiment, aiming to resolve a long-standing anomaly regarding the magnetic moment of muons. This experiment delves into the quantum realm, exploring how short-lived particles popping in and out of existence influence the magnetic properties of muons. The initial results from this experiment suggested that the Standard Model of physics might be incomplete, hinting at the presence of undiscovered particles or forces.

The experiment's findings continue to show a discrepancy between experimental measurements and the predictions of the Standard Model. However, the statistical significance of this discrepancy has decreased due to improvements in theoretical calculations. This implies that while the Standard Model may not fully account for the behavior of muons, the evidence for new physics is not as strong as previously thought. The result is at 4.2σ (standard deviations) away from what's calculated using the Standard Model, which is a bit short of the 5 sigma normally used to declare a discovery. There's about a 1 in 40,000 chance that this is a fluke.

Despite the reduced statistical significance, the results remain intriguing and motivate further research. The possibility of undiscovered particles influencing muons still exists, pushing physicists to explore new theoretical models and conduct additional experiments. Fermilab shared first results from their "g-2" experiment showing the Standard Model of physics is even more incomplete than we thought. If the universe includes particles we don't yet know about, these too will show up as fluctuations around particles, influencing the properties we can measure.


References :

• astrodon.social: Anomaly no more! “Muon g-2†puzzle resolved at last Can theory and experiment agree on the magnetic moment of the muon? At last, a new theory initiative paper coupled with final, world's best experimental results point to the resolution.
• Ray Lee: Fermilab is announcing final results from the muon g-2 experiment today! I'm heading out the door, but the results will be at 10am CT. Quoting myself from April 7th, 2021: Fermilab shared first results from their "g-2" experiment showing the Standard Model of physics is even more incomplete than we thought.
• bigthink.com: Anomaly no more! “Muon g-2†puzzle resolved at last Can theory and experiment agree on the magnetic moment of the muon? At last, a new theory initiative paper coupled with final, world's best experimental results point to the resolution.
• Ray Lee: I should add, there have been various papers since this announcement back in 2021 that claim the calculations were incomplete and newer methods, such as brute-forcing the calculation via SM lattice methods on supercomputers, has pushed the discrepancy with experiment down to less than 2 sigma. Today we'll learn more! 3/3
• physics.aps.org: Link to the stream: A rather nice cartoon explainer of all this by Jorge Cham: An accessible and slightly more scientific walkthrough over at Quanta Magazine from 2021: And the below graphic, showing how one particle physicist (who's name escapes me), viewed the tension in the results, four years ago. 2/3

Classification:

• HashTags: #MuonG2 #StandardModel #ParticlePhysics
• Company: Fermilab
• Target: Particles
• Product: Physics
• Feature: Measurement
• Type: Research
• Severity: Interesting