Search for Dark Matter in events with a hight- p$_T$ photon and high missing transverse momentum in ATLAS

We present the results of a search for new particles in events with a high-pT photon and high missing transverse momentum with the ATLAS experiment at the LHC. The analysis is performed on the data collected by ATLAS at a centre of mass energy of 8TeV and corresponding to a total integrated luminosity of 20.3 fb$^{−1}$. No excess has been found with respect to the Standard Model expectation. A modelindependent upper limit on the fiducial cross section for the production of events with a photon and large missing transverse momentum is set. Exclusion limits on the direct pair production of dark matter candidates are presented.