A Search for Randall-Sundrum Gravitons Decaying to Photon Pairs in √s = 7 TeV pp Collisions at the ATLAS experiment of the Large Hadron Collider

A variety of new physics models involving extra dimensions predict photons in the final states from pp collisions at energies accessible at the Large Hadron Collider. The search for new particles in the diphoton channel, such as the Kaluza-Klein resonant mode of the graviton in the Randall-Sundrum model, carried out by the ATLAS experiment is presented. Event selection and optimization, as well as data-driven methods for estimating the background and efficiencies are discussed. Particular emphasis is given to the statistical treatment for the contrast of the null and alternative hypothesis. Making use of 36 pb-1 of pp collisions data at $sqrt{s} = 7$ TeV , bounds on the production cross section times branching ratio for the Randall-Sundrum graviton as a function of diphoton mass are shown, including a comparison with the results from Tevatron.