Phenomenological study of the minimal R-symmetric supersymmetric standard model

The Standard Model (SM) of particle physics gives a comprehensive description of numerous phenomena concerning the fundamental components of nature. Still, open questions and a clouded understanding of the underlying structure remain. Supersymmetry is a well motivated extension that may account for the observed density of dark matter in the universe and solve the hierarchy problem of the SM. The minimal supersymmetric extension of the SM (MSSM) provides solutions to these challenges. Furthermore, it predicts new particles in reach of current experiments. However, the model has its own theoretical challenges and is under fire from measurements provided by the Large Hadron Collider (LHC). Nevertheless, the concept of supersymmetry has an elegance which not only shines in the MSSM. Hence, it is also of interest to examine non-minimal supersymmetric models. They have benefits similar to the MSSM and may solve its shortcomings. R-symmetry is the only global symmetry allowed that does not commutate with supersymmetry and Lorentz symmetry. Thus, extending a supersymmetric model with R-symmetry is a theoretically well motivated endeavor to achieve the complete symmetry content of a field theory. Such a model provides a natural explanation for non-discovery in the early runs of the LHC and leads to further predictions distinct from those of the MSSM. The work described in this thesis contributes to the effort by studying the minimal R-symmetric supersymmetric extension of the SM (MRSSM). Important aspects of its physics and the dependence of observables on the parameter space of the MRSSM are investigated. The discovery of a scalar particle compatible with the Higgs boson of the SM at the LHC was announced in 2012. It is the first and crucial task of this thesis to understand the underlying mechanisms leading to the correct Higgs boson mass prediction in the MRSSM. Then, the relevant regions of parameter space are investigated and it is shown that they are also in agreement with other Higgs observables. Another observable that is measured with great accuracy and especially sensitive to corrections from additional supersymmetric states is the mass of the W boson. Contributing effects within the MRSSM are identified and their dependency on the model parameters is studied. The presence of a stable supersymmetric particle as candidate for dark matter is a prediction of the MRSSM. The interplay of the relevant processes generating the correct abundance of dark matter in the universe and explaining the non-discovery by direct searches is investigated. Moreover, results of Run 1 of the LHC are used to study the electroweak MRSSM sector. This leads to a classification of viable regions of parameter space consistent with dark matter and LHC constraints. In the last part of this thesis the different observables are analyzed in coherence. This allows to identify valid regions of parameter space and highlights promising predictions of the MRSSM for the coming runs of the LHC and other experiments.