Studies of particle production in inelastic pp events with the ATLAS detector

The measurement of the properties of proton-proton interactions at center-of-mass energies of 900 GeV, of 2.36 TeV and of 7 TeV in the ATLAS detector are presented. The charged-particle density, its dependence on transverse momentum and pseudo-rapidity, and the relationship between transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in a defined kinematic range. The measurements are compared to Monte Carlo models for inelastic events and to results from other experiments. and Studies of the long-lived resonances Ks and Lambda, reconstructed in inelastic collisions at 900 GeV and 7 TeV using a minimum bias trigger, have been performed using the ATLAS inner tracking detector. The spectra for these resonances are measured as a function of their transverse momentum and rapidity, and compared with Monte Carlo models.