  In the first part of this thesis, we consider an extension to the Standard
Model composed by a Massive Vector Doublet under SU(2)L and a Left-handed Heavy
Neutral Lepton. We study the production of these exotic leptons with a Same
Flavor Opposite Sign standard lepton pair, and jets. We establish limits on the
parameter space considering previous searches in this final state. After the
limit definition, we study a modification on the event selection criteria in
order to increase the possibility of probing these new particles at the Large
Hadron Collider. Finally, we perform a parameter scan considering the new
lepton as a dark matter candidate, identifying relevant regions on the
parameter space for future studies.
