Investigating a Possible Dynamical Origin of the Electroweak Scale

Who: Martin Rosenlyst Jørgensen (CP3-Origins)
When: Thursday, June 1, 2017

One era came to an end in July 2012 when two experiments, CMS and ATLAS, at the Large Hadron Collider at CERN announced the discovery of a new resonance consistent with the Standard Model Higgs boson. The Higgs boson was the last missing piece of the Standard Model of elementary particle physics, our most fundamental description of the elementary particles and their interactions via three of the four forces, the exception being gravity. Although the Standard Model is in agreement with a great number of experimental measurements, it cannot explain all the observations.
The thesis begins with an introduction to the Standard Model, the reasons why there must be some more fundamental theory beyond the Standard Model. This thesis will elucidate extensions of the Stan- dard Model, where the Higgs sector is replaced by a strongly interacting sector. We will focus mostly on the naturalness i.e. the problem that the mass of the Higgs boson is very 􏰜ne-tuned.
Therefore, in this thesis we will investigate extensions of the Standard Model, where the standard Higgs sector is replaced by a strongly interacting sector. After we have developed the tools to study strongly interacting theories, we will discuss and develop three concrete examples: the Minimal Walking Technicolor (MWT) model, a Composite Higgs (CH) model and a Partially Composite Higgs (PCH) model. We will investigate the vacuum stability of the PCH model by calculating the running of a new fundamental scalar self-coupling, and we discover that this kind of models are 􏰜ne-tuned and the vacuum is unstable for a large part of the parameter space. This part of the thesis is novel research.