Experimental value of muon g-2 updated

E989 collaboration announced the latest experimental value of muon g-2

Muon g-2 = 0.00233184110 +/- 0.00000000043 (stat.) +/- 0.00000000019 (syst.)

This result is based on data collected in 2018, 2019, 2020. E989 collaboration is now finished with data collection and will announce the final result based on 6 years of data in 2025. They expect to reduce the error bar by half.

Why is this important?

“Because information from every particle and force is encoded in the numerical value of the muon’s magnetic moment. If we can both measure and predict this number to ultra-high precision, we can test whether the Standard Model of Elementary Particles is complete.” – FERMILAB

Theoretical prediction and experimental value differ significantly

Tension between the experimental value and the theoretical predictions continue. Predicting the numerical value of the magnetic moment of the muon is one of the hardest calculations in particle physics. Theoretical predictions based on the lattice gauge theory are closer to the new experimental value. By 2025, if the difference between the theoretical prediction and the experimental value is still statistically significant then we will be sure there is new physics beyond the Standard Model.

Press release (August 10, 2023)

Scientific paper

My previous blog posts on muon g-2