  Precision studies of single W and Z production processes at hadron colliders
require progress in the calculation of electroweak radiative corrections. To
this end, higher-order QED corrections to the neutral-current Drell-Yan
process, due to multiple photon radiation in Z leptonic decays, are calculated.
Particular attention is paid to the effects induced by such corrections on the
experimental observables which are relevant for high-precision measurements of
the W-boson mass at the Tevatron Run II and the LHC. The calculation is
implemented in the Monte Carlo event generator HORACE, which is available for
data analysis.
