Heavy-ion physics with the ATLAS detector at the LHC

First results on jet, Jψ and Z production are presented from the first lead-lead run at the LHC, using the ATLAS detector. The transverse energies of opposed dijets are observed to show greater asymmetry with increasing event centrality, something not observed in proton-proton collisions. This may point to an interpretation in terms of strong jet energy loss in a hot, dense medium. Also, using the ATLAS muon spectrometer, a centrality-dependent suppression has been observed in the yield of J/ψ mesons. It is found to be qualitatively similar to the trends observed at previous, lower-energy experiments. The relative yields of Z bosons as a function of centrality are also presented, although the low statistics precludes any strong conclusions. These results provide a first look at the modification of high-pT processes in heavy-ion collisions at the highest-available beam energy