# Measuring the fine-structure constant to refine Standard Model predictions

- Institution: CERN
- Department: EP Seminar
- Speaker: Saida GUELLATI
- Year: 2021
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3007539)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

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.

EP Seminar 4 May: https://cern.zoom.us/j/61684350049?pwd=RStaOFVBa2ZMeGozTDliWkw2ZG53UT09.

0:00:00 Slide 1

0:06:22 Slide 2

0:12:44 Slide 3

0:19:05 Slide 4

0:25:27 Slide 5

0:31:49 Slide 6

0:38:10 Slide 7

0:44:32 Slide 8

0:50:53 Slide 9

0:57:15 Slide 10

1:03:37 Slide 11

## Lectures

1. [Measuring the fine-structure constant to refine Standard Model predictions](https://invisiblenetwork.ai/learn/cern/3007539/7fb846088fd6), 1 h 4 min (CERN's player)