Measurement of Inclusive Two-Particle Angular Correlations in Proton-Proton Collisions at sqrt{s} = 900 GeV and 7 TeV

Measurements of two-particle angular correlations in proton-proton collisions at centre-of-mass energies of 900 GeV and 7 TeV are presented. Correlations are measured for charged particles in the kinematic region pT > 100 MeV and |η| < 2.5 in Minimum Bias events, using data collected by the ATLAS detector at the LHC during 2009 and 2010. A complex correlation structure in Δη and Δφ is observed at both energies. Results are compared to Pythia 8 and Phojet as well as the MC09, DW and Perugia0 tunes of Pythia 6.