Item

Abstract

In this thesis the spectrum of top partners in the minimal composite Higgs model with
fundamental fermionic representation is explored. It is shown that by using a recently
developed softened symmetry breaking mechanism for the global symmetry, top partner
masses above 1.5TeV for a realistic Higgs mass of 125GeV can be produced without
raising the symmetry breaking scale. For a maximally symmetric version of this model,
which has also just been proposed, top partner masses above 2TeV can be realized,
while simultaneously a significantly reduced fine-tuning of O(10) is achieved providing a
quantitative proof for the existence of a natural minimal composite Higgs model which
is not in tension with current observations. To carry out this analysis, the 4-dimensional
effective field theory of the softened symmetry breaking is reviewed and then embedded
into a 5-dimensional holographic theory through the AdS/CFT duality. Numerical scans
on the resulting particle spectrum and the tuning in the holographic dual are performed
including a detailed parameter study of the outcome. A theoretical review of the 4- and
5-dimensional picture as well as their maximally symmetric extensions is also provided.