Study of $Z \to ll\gamma$ decays at $\sqrt{s}$ = 8 TeV in the ATLAS experiment at the LHC

This note presents a study of $Z \to ll\gamma$ decays in the ATLAS experiment at the Large Hadron Collider. The analysis uses a proton--proton data sample corresponding to an integrated luminosity of 20.2~fb$^{-1}$ collected at a centre-of-mass energy $\sqrt{s}$ = 8 TeV. Integrated fiducial cross-sections together with normalised differential fiducial cross-sections, sensitive to the kinematics of final-state QED radiation, are obtained. The results are found to be in agreement with state-of-the-art predictions for final-state QED radiation. First measurements of $Z \to ll\gamma\gamma$~decays are also reported.