Production of vector bosons in association with jets in ATLAS

Abstract: Measurements of the production of jets in association with a W/Z boson in proton-proton collisions are presented using data collected by the ATLAS experiment at LHC at sqrt s = 8 and 13 TeV. Several kinematic regimes are explored with various approaches to probe different aspects of these processes. The differential cross sections of a Z boson in association with jets with pT > 30 GeV and |y|< 2.5 at sqrt s = 13 TeV are measured in a fiducial phase space, probing strong interactions that completely dominate in these processes, while measurements of a W boson in association with at least two jets at high pT and high di-jet invariant mass, where the electroweak production is enhanced, are performed with sqrt s = 8 TeV data. Angular distributions in W+jets events with high pT jets are also measured at sqrt s = 8 TeV focusing on small angular separation between the jets and the W decay products, where contributions from real W emission are expected large. Finally a measurement of the splitting scales occurring in the kt jet-clustering algorithm is presented for final states containing a Z boson at sqrt s = 8 TeV. This measurement based on charged-particle track information constitutes a complementary approach to study jet properties. Data distributions of all the measurements are corrected for detector effects and compared with state-of-art predictions.