Dark sector searches with the mono-jet signature at the ATLAS detector at the LHC

This work investigates the possibility that dark matter could be produced at collider facilities, under the assumption that is weakly coupled to the ordinary matter and that it constitutes a new sector of particles (the dark sector). Under the assumption of a long-lived mediator that escapes detection in the detector, the mono-jet signature, in which high missing transverse momentum recoils against a highly energetic jet, is exploited.