# g-2 short study and discussion

*The Muon g-2 experiment measures the magnetic moment of the muon with high precision. The results are, well, interesting. *

Images courtesy of Fermi National Accelerator Laboratory,

## Workshop Group Tutorial for Teachers

__Questions__:

- What are magnetic moment (hyperphysics) and gyromagmnetic ratio (Almost Complex Structure)?
- How do these show up for a small charged particle moving in a magnetic field?
*Time for a crazy human trick!* - What do we mean by g-2? (
__Hint__: It is*not*7.81 m/s^{2}.) - The theoretical value of g, according to the Standard Model, is g = 2.00233183620(86).
- According to QED, g = 2. The remaining decimals are from QCD and the Standard Model.
- To get the anomalous magnetic moment, a
_{μ}first get the difference between the full theoretical value of g and the QED value of g, which we'll call g_{QED}. Then divide by g_{QED}. In (no) other words, a_{μ}= (g - g_{QED})/g_{QED}= (g-2)/2. - Can you find the theoretical value of the anomalous magnetic moment, a
_{μ}?

- Now let's make sense of the chart below from Fermilab.

*In case you missed the calculation, theoretical a _{μ} = 0.00116591810(43).*

__Resources__:

- Fermilab Muon g-2 ← primary (use side menu)
- First results at Fermilab
- Wikipedia
- Video: What does the Muon g-2 experiment tell us?

__Probing Deeper__:

- Muon g-2: A review, Nuclear Physics B, Volume 975, February 2022