The ATLAS liquid argon calorimeters: construction, commissioning, and selected beam results

All modules of the ATLAS electromagnetic calorimeter (32 barrel and 16 end-cap modules) are now assembled. The four wheels of the ATLAS hadronic endcap calorimeter and the two forward calorimeters are built and are being inserted in the cryostats. The status of the integration and tests at CERN are presented. Several production modules of the electromagnetic calorimeter (4 for the barrel, 3 for the endcap) have been tested on SPS electron beams, from 5 to 250 Ge V. A selection of results will be discussed with particular attention to linearity, uniformity, position and time measurement, photon- neutral pion and electron-pion separation. Besides, a segment of the electromagnetic and hadronic liquid argon endcap calorimeters, in a setup close to that of the ATLAS experiment, have been exposed to electron, pion and muon beams in the energy range 6 GeV to 200 GeV. Results on the hadronic shower signal reconstruction are presented.