# Gauge Invariance and Observables in Particle Physics

#### Gauge Invariance and Observables in Particle Physics

- Event time: 2:00pm until 3:00pm
- Event date: 17th April 2024
- Speaker: Axel Maas (University of Graz)
- Location: Higgs Centre Seminar Room, Room 4305, James Clerk Maxwell Building (JCMB) (James Clerk Maxwell Building (JCMB)) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

Title: Gauge Invariance and Observables in Particle Physics

Abstract:

On a formal, fundamental level in a non-Abelian gauge theory only

composite fields can be gauge-invariant, rather than the elementary

fields employed in perturbation theory. While at first sight in

contradiction to the phenomenological success of perturbation theory in

electroweak physics, there is a deeper reason for both being compatible,

the Fröhlich-Morchio-Strocchi mechanism. Its working and validity has

been demonstrated explicitly in lattice simulations. However, even then

this leaves still room for new phenomena in the standard model.

Moreover, the standard model is special. Beyond the standard model these

issues yield qualitative changes and affect such varied scenarios like

grand-unified theories, supersymmetry, and quantum gravity.

The talk provides an overview of the underlying mechanisms, including

some lattice results in their support, and finally highlights a few

example applications.

### About Particle Physics Theory seminars

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..