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Abstract

In this thesis we investigate the fundamental features of radiatively induced spontaneous
symmetry breaking (RSSB) in multiscalar models without classical mass
terms. Motivated by addressing the hierarchy problem via the extension of the
conformal standard model (cSM) we present a general formalism to analyze the
generation of non-trivial minima in the one-loop effective potential via a set of exact
criticality equations. Given the intuitive nature of these equations we are able
to systematically analyze the RSSB in classically conformal multiscalar models.
Specifically, we investigate the interplay of contributions by different particles at
the scale of condensation and in the renormalization group running of the coupling
parameters. We compare the observed features of RSSB to results obtained when
using the commonly used Gildener-Weinberg approximation, which additionally
assumes the existence of a flat direction at tree-level. Without making further
assumptions to classical scale-invariance we already find cases where one-loop
gauge contributions can generally be of the same order of magnitude as the scalar
tree-level terms. Thus, allowing for the generation of non-trivial vacua without a
tree-level flat direction. The analysis using our approach reveals qualitatively new
scenarios of RSSB compared to the Gildener-Weinberg approximation and allows
for an intuitive investigation of fundamental properties of scale-setting without
making further assumptions to classical scale-invariance.