Supersymmetry at pp¯, pp and e+e− Colliders in Light of Wmap Measurements of the Dark Matter Density of the Universe

The Standard Model (SM) describes almost all the particle physics experiments with a high accuracy. However, the SM has a lot of conceptual problems (spontaneous symmetry breaking is introduced by hand, the Higgs boson mass has to be very finely fine-tuned, there is no explanation for the number of generations or particle quantum numbers, there are at least 19 arbitrary model parameters). Therefore, it is reasonable to search for theories solving some or all of the problems that the SM has. One class of such theories is based on an assumption that at some large energy scale Nature chooses the maximal possible space-time symmetry, called supersymmetry (SUSY). Once the theory is constructed, it has to be tested against the experiment. This dissertation explores various collider signals in the framework of minimal Supergravity model (mSUGRA) and gaugino mediated SUSY breaking model (inoMSB). We calculate whether the signal predicted by these models could be detected at the Fermilab Tevatron and at the CERN LHC hadronic colliders, and also explore the capabilities of a future electron-positron Linear Collider. We show the collider reach contours in the mSUGRA parameter space, combined with constraints from other experiments. We also devise new cuts, optimizing the signal to background ratio in the regions where no such work was previously done.