Endcap Photon Fake Rate Study: Background Estimation for ADD and RS Graviton Searches

We present a photon fake rate calculation for the endcaps that is used to estimate the reducible background components for high-mass diphoton resonances. Such resonances could be a signature of an excited state of either a Randall-Sundrum or ADD graviton. Quark and gluons may fragment in such a way that they produce fake photon signatures in the detector. A proper estimation of the reducible background is important in setting limits for the search for any excess over the total background. The data presented here are from proton-proton (pp) collisions at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.5fb−1. The same method is planned to be applied for data taken at a centre-of-mass energy of 13 TeV.