QED Radiative Processes in Deep Inelastic Scattering at HERA

High energy scattering processes of charged particles are accompanied by radiation of hard photons. Emission collinear to the incident particles, which leads to a reduction of the eective beam energy, and the possibility to directly measure these photons at the HERA electron-proton collider provides important physics opportunities. For deep inelastic scattering, the measurement of radiative processes extends the kinematic range accessible to the HERA experiments to lower Q 2 , as well as helps in separating the proton structure functions without the need to run at dierent collider energies. QED corrections to these radiative processes are discussed, and the calculation of the model-independent leptonic corrections is described in some detail for the complete one-loop contributions as well as for the higher order leading logarithms.