The fine structure constant is this "magic and enigmatic" number close to 1/137 that appears in several areas of physics. This dimensionless constant characterizes the strength of the electromagnetic interaction between light and charged elementary particles, such as electron or muon. A precise knowledge of its numerical value is crucial to test, even with low-energy experiments, the calculations of quantum electrodynamics and some theoretical predictions of the Standard Model.
In this seminar, I will present our experiment that recently led to a new determination of the fine-structure constant with a relative uncertainty of $8.1 \times 10^{-11}$ and discuss the impact of this result on the tests of the Standard Model.
M. Pepe-Altarelli, P. Silva