Search for ADD Direct Graviton Emission in Photon plus Missing Transverse Energy Final State at CMS

The exclusive gamma and met signature is used as a probe for the discovery reach of ADD large extra dimensions at the CMS detector. Signal samples for various model parameters as well as possible backgrounds have beensimulated partially using the CMS fast detector simulation. The reconstruction performance and efficiency obtained with the fast simulation has been compared with the detailed full simulation. A normalisation method is proposed to measure the main background Z (rightarrow nunubar) +gamma with high precision using reference spectra from Z (rightarrow mu^+mu^-) + gamma and Z (rightarrow e^+ e^-) + gamma. The discovery reach at the LHC with CMS is presented and the potential to determine parameters of the underlying model is discussed.