Gluino solutions from grand unified theories to the large hadron collider

In this thesis we discuss the gluino mass in the CMSSM and Nonuniversal Gaugino Mass Models (NUGM) frameworks in light of the results from the current LHC and Dark Matter experiments. Assuming negative results from the current and near future LHC experiments, we probe the gluino mass scales by considering its decay modes into stop and top quarks. The region with gluino mass ≲ 2 TeV is excluded up to 68% CL in the CMSSM if the gluino decays into a stop and top quark, while the 95% CL exclusion requires gluino mass ≳ 1.9 TeV. Considering an error of about 10% in calculations of the SUSY mass spectrum, such exclusion bounds on the gluino mass more or less overlap with the current LHC results. Gluino can decay into top quarks with LSP neutralino if not allowed to decay into stop and top quark. One can probe the gluino mass in this case up to about 1.5 TeV with 68% CL in the CMSSM, and about 1.4 TeV with 95% CL. Imposing the Dark Matter constraints yields a lower bound on the gluino and stop masses of about 3.2 TeV from below, which is beyond the reach of the current LHC experiments. A similar analyses in the NUGM framework yield exclusion curves for the gluino mass ≳ 2.1 TeV at 14 TeV for both decay modes of the gluino under consideration. We also show that increasing the center of mass energy to 27 TeV can probe the gluino mass up to about 3 TeV through its decay mode into stop and top quark. The Dark Matter constraints are not very severe in the framework of NUGM, and they allow solutions with stop and gluino masses ≳ 1 TeV. With the 100 TeV FCC collider one can probe the gluino masses up to about 9 TeV with 3000 fb^-1 integrated luminosity.