Measurement of Underlying Event Observables with the ATLAS detector
The modelling of the Underlying Event (UE) is a crucial component in the complete description of both soft and hard QCD processes at hadron colliders. The ATLAS collaboration presents new results on the number and transversemomentum sum of charged particles as a function of the leading high pT track in events taken at a center of mass energy of 13 TeV. These results are presented in regions towards, transverse, and away from the leading track and allow to test the modelling of the Underlying Event in modern MC generators. Furthermore, eventshape variables based on charged particles have been measured in Z-events at 7 TeV and have been compared with the predictions of different stateoftheart MC generators. These measurements test the Underlying Event in a complementary way.