PSILOGO

Laboratory for Particle Physics (LTP)


LTP Colloquium

Measuring the Fine-Structure Constant to refine the Standard Model Predictions

Thursday, March 25, 2021, 16:00
online only                                             (for the zoom link contact michael.spira@psi.ch, emanuele.bagnaschi@psi.ch or pulak.banerjee@psi.ch)

Saïda Guellati-Khélifa, LKB/Sorbonne Université

Abstract:
The fine-structure constant "alpha" is this "magic and enigmatic" number close to 1/137 that appears in the various fields of physics. This dimensionless constant characterizes the strength of the electromagnetic interaction between light and charged elementary particles, such as electron or muon. Knowing accurately 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 talk, I will present our experiment which recently led to a new determination of the structure-fine constant with a relative uncertainty of 8.1 x 10-11 and I will discuss the impact of this result on the tests of the Standard Model.