Photon Physics at the LHC

This thesis reports on the first studies of Standard Model photon production at the Large Hadron Collider (LHC) using

the ATLAS detector.  Standard Model photon production is a large background in the search for Higgs bosons decaying into

photon pairs, and is thus critical to understand.  The thesis explains the techniques used to reconstruct and identify

photon candidates using the ATLAS detector, and describes a measurement of the production cross section for isolated

prompt photons.  The thesis also describes a search for the Higgs boson in which the analysis techniques used in the

measurement are exploited to reduce and estimate non-prompt backgrounds in diphoton events.