Search for monotop events using the ATLAS detector at the LHC

A search for the production of single-top-quarks in association with missing energy performed in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=8$ TeV with the ATLAS experiment is presented. No deviation from the Standard Model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark.