Measurements of the Vector boson production with the ATLAS Detector

Abstract

The electroweak sector of the Standard Model can be tested by precision measurements of its fundamental parameters, such as the W boson mass or the electroweak mixing angle. In this contribution we present the first measurement of the W boson mass, based on the 7 TeV data set corresponding to an integrated luminosity of 4.6 fb-1. With this data set the detector and physics modelling have been studied in great detail, leading to an overall uncertainty of 19 MeV. The ATLAS collaboration also performed a new precise triple differential Z/γ* Drell-Yan cross-section measurement as a function of the dilepton mass, the dilepton rapidity and cos θ* defined in the Collins-Soper frame. This measurement provides sensitivity to the PDFs and the Z forward-backward asymmetry, AFB, which is derived and will be presented. The latter builds the foundation for a possible future extraction of the weak-mixing angle. The production of jets in association with vector bosons is an important process to study perturbative QCD in a multi-scale environment. The ATLAS collaboration has performed new measurements of vector boson plus jets cross sections, differential in several kinematic variables, in proton-proton collision data, taken at center-of-mass energies of 8 TeV and 13 TeV. These measurements are presented and compared to state-of-the art theory predictions. They are sensitive to higher-order pQCD effects, and can be used to constrain the proton structure. In addition, we present a new measurement of the splitting scales of the kt jet-clustering algorithm for final states containing a Z-boson candidate at a centre-of-mass energy of 8 TeV.