  We review, in the first part of this work, many pioneering works on
supersymmetry and organize these results to show how supersymmetric quantum
field theories arise from spin-statistics, N{\oe}ther and a series of no-go
theorems. We then introduce the so-called superspace formalism dedicated to the
natural construction of supersymmetric Lagrangians and detail the most popular
mechanisms leading to soft supersymmetry breaking. As an application, we
describe the building of the Minimal Supersymmetric Standard Model and
investigate current experimental limits on the parameter space of its most
constrained versions. To this aim, we use various flavor, electroweak
precision, cosmology and collider data. We then perform several
phenomenological excursions beyond this minimal setup and probe effects due to
non-minimal flavor violation in the squark sector, revisiting various
constraints arising from indirect searches for superpartners. Next, we use
several interfaced high-energy physics tools, including the FeynRules package
and its UFO interface that we describe in detail, to study the phenomenology of
two non- minimal supersymmetric models at the Large Hadron Collider. We
estimate the sensitivity of this machine to monotop production in R-parity
violating supersymmetry and sgluon-induced multitop production in R-symmetric
supersymmetry. We then generalize the results to new physics scenarios designed
from a bottom-up strategy and finally depict, from a theorist point of view, a
search for monotops at the Tevatron motivated by these findings.
