Searches for monojets and monophotons with the ATLAS detector

Studies of events with a single high energy jet or photon, and large missing transverse momentum at the Large Hadron Collider is one of the most effective ways to search for physics beyond the Standard Model. The background from the Standard Model processes is dominated by jet/photon production associated with Z or W bosons undergoing leptonic decays to neutrinos and/or unidentified electrons or muons. The sensitivity to new physics signals relies on the good understanding and the accurate estimation of these backgrounds, and therefore the use of data-driven techniques is often required. In this article, I will present a compilation of the latest results from the monojet and monophoton searches based on the analysis of the 2011 and 2012 proton-proton collision data collected with the ATLAS detector at a center-of-mass energy of 7 TeV and 8 TeV, respectively. The results are interpreted in the context of various models beyond the Standard Model including large extra dimensions, gauge mediated supersymmetry breaking and effective field theory of dark matter production