Abstract

The conundrum of Dark Matter has been attacked for decades. Numerous independent astrophysical experiments have observed this mysterious substance, which comprises five times more of the Universe’s content than ordinary visible matter. The defining characteristic of DM is that it has only been observed to interact via the gravitational force, however DM may interact with particles from the Standard Model (SM) through some force at the weak scale or below. In this paradigm, DM particles are taken to be a type of Weakly Interacting Massive Particle (WIMP) which might be produced in hadronic collision at the LHC . Search for DM at ATLAS are extremely important as they can can probe entirely new regions of phase space. However WIMP DM particles are unobservable by ATLAS and stable enough not to decay within the detector. They manifest as Missing Momentum in the Transverse plane (MET). The presence of particles recoiling against WIMPS leads to a monoX+MET signature. Searching for such rare processes requires outstanding performance in terms of measurements of momenta of all the particles produced in the interactions (leptons, photons, hadronic jets) and dedicated techniques to suppress fake signals. In this talk, the key experimental points of the current searches for DM signatures at ATLAS are reviewed, together with the current results in the LHC Run-I data.