Nuclear and Particle Physics

A critical look at the electroweak phase transition

by Johan Löfgren (U)

Europe/Stockholm
694 8338 9142 (Zoom)

694 8338 9142

Zoom

https://uu-se.zoom.us/j/69483389142
Description
This will a virtual seminar, hosted in Zoom

Meeting ID: 694 8338 9142

Direct link: https://uu-se.zoom.us/j/69483389142

This meeting is password protected, if you are interested in joining, send an email to rebeca.gonzalez.suarez@physics.uu.se

Final PhD seminar
 
As the early universe expands and cools down, the Higgs field develops a vacuum-expectation-value—breaking the electroweak symmetry. This phase transition might explain the asymmetry between matter and antimatter. It might also generate detectable gravitational waves.

In particle physics we deduce properties of the phase transition by using perturbative methods. But these methods suffer from severe problems such as gauge dependence, infrared divergences, and a breakdown of perturbation theory.

We have developed robust perturbative techniques to deal with the phase transition, and argue that a consistent power-counting is crucial.

In this talk I will discuss how the Higgs mechanism is affected by quantum and thermal fluctuations. I will describe the issues of the perturbative expansion, and how to resolve them. I will also show some numerical calculations performed in the Standard Model.