Studies of the underlying event with ATLAS

Particle distributions sensitive to the underlying even have been measured with the ATLAS detector at the LHC. Charged particle multiplicity, charged and inclusive sum transverse momentum (pT) densities and mean charged-particle pT in the regions of each event, azimuthally transverse to the hardest jet, are also presented. When compared to the predictions of different Monte Carlo models, the data show sensitivity to the modelling of the underlying event.