Physics Performance Studies and Strategy of the Electron and Photon Trigger Selection

This note gives an overview of the implementation and performance of the electron and photon selection by the ATLAS trigger system. Trigger menus for commissioning as well as for the first physics run are presented together with the strategy for the early data taking phase. The physics performance in terms of selection efficiency and background rejection has been estimated using MC simulations for various luminosity scenarios. An example of a method to determine trigger efficiency from real data using Z to ee events is discussed.