This thesis presents a measurement of collinear ?-boson radiation from high-momentum jets using the full Run-2 dataset collected by the ATLAS collaboration at √? = 13 TeV, with an integrated luminosity of 140 fb−1 . The W+ jets signal, identified through leptonic decays in the electron or muon channels, focuses on events with small angular separation between the jet and lepton, often involving numerous QCD emissions. Accurate modeling of this phase-space requires sophisticated multi-jet merged setups. Over 86,000 ?-boson candidates were measured across various differential distributions with a precision of10-20%, and the data was compared against newly developed state-of-the-art generator predictions using Sherpa 2.2.11 and MadGraph5_aMC@NLO with FxFx multi-jet merged setups, which are accurate to next-to-leading order in the strong and weak coupling constants.