Registration will close on 15 August 2025.
The viability of the anomalous magnetic moment of the electron, $a_e$, as a powerful probe of physics beyond the Standard Model (BSM), depends crucially on independent input for the fine-structure constant $\alpha$. At present, the two most precise determinations, from atom interferometry using Cs and Rb atoms, respectively, differ by $5.4\sigma$. Moreover, the precision of the SM prediction for $a_e$ is limited by the knowledge of higher-order QED calculations and hadronic vacuum polarization, which will become relevant once the current puzzle in $\alpha$ is resolved.
In the workshop, we aim to make progress regarding precision measurements and calculations of $\alpha$ and $a_e$, to try and resolve the current tensions and further improve the precision. In addition, the workshop will explore alternative approaches for precision determinations of $\alpha$ --- bound-state $g$-factors and muonic spectroscopy --- to identify the best strategies to constrain BSM effects in $a_e$ at the highest precision achievable. When combined with $a_\mu$, the result has immediate consequences for the flavor and chirality structure of potential BSM effects accessible with lepton anomalous magnetic moments.
