Search for new physics in a monojet plus missing transverse energy final state with ATLAS

A monojet plus large missing transverse energy final state is of interest as it is foreseen as a signal in several beyond SM physics scenarios. The search for new physics in this event topology is performed in pp collisions at √(s)=7 TeV with ATLAS. The analysis is model independent and three kinematic regions are explored. Results from the analysis are interpreted in terms of the ADD extra dimensions model. As with every search, a major challenge is the understanding and suppression of SM backgrounds. Vector boson+jet production constitutes the dominant contribution to the background for this signal. The irreducible background for this signal is Z+jet production where the Z decays to a neutrino-antineutrino pair giving rise to large missing transverse energy. The estimate for this background is obtained using a data driven method. Latest results from the analysis are presented using the 2011 dataset.