New results on W boson production with the ATLAS detector

Measurements of the production of jets in association with a W boson or a same-sign W boson pair in proton–proton collisions are presented using data collected by the ATLAS experiment at LHC at √s= 8 and 13 TeV. The cross section of the W boson production in association with jets is measured in nal states containing one electron and missing transverse momentum and jets with pT > 20 GeV and |y|<4.4. The measurement probes strong interactions, that completely dominate in these processes. The cross-section ratio of W+/W− is also measured in the same final state, improving the precision of the measurement. The observables and ratios selected provide valuable input for the understanding of parton distribution functions of the proton. A study of same-sign W boson pair production in association with two jets is performed requiring a large invariant mass and rapidity di erence of the jets. This mea- surement probes the scattering of two W bosons, that is a key process to test the nature of electroweak symmetry breaking. The observation and fiducial cross-section measurement of electroweak production of this nal state are presented.